Associations between maternal overweight and obesity with cesarean section delivery in Middle East and North Africa region: a systematic review, meta-analysis, and attributable risk

Abstract

Background

Over the past 30 years, the global use of cesarean section (CS) has increased significantly, surpassing the recommended population-based rate of 10–15%. Increased maternal weight is a major factor for cesarean section (CS) delivery.

Objective

This systematic review and meta-analysis assessed the association between maternal overweight/obesity and CS delivery, estimating the proportion of CS deliveries attributable to excess maternal weight in Middle East and North Africa (MENA) countries.

Methods

Electronic databases (PubMed, Scopus, Embase, CINAHL, Web of Science, and Cochrane) were searched for studies published between Jan 2000 and Nov 2024 in MENA countries. Two authors reviewed studies and extracted data. Subgroup analyses examined obesity class (I–III) and CS type. Attributable risk fractions (ARFs) and population-attributable risk fractions (PARFs) were calculated. Random-effects models were used.

Results

Forty-five studies from 12 MENA countries, including 97,518 women, were analyzed. Compared to women with a normal body mass index (BMI), overweight and obese women had a 35.0% (aOR 1.35; 95% CI, 1.24–1.49) and a 77.0% (aOR 1.77; 95% CI, 1.49–2.11) elevated likelihood of CS, respectively. The likelihood of CS significantly increased with increasing obesity class by 78% for class I, 121% for class II, and 161% for class III. Overweight women were also at higher risk of emergency CS (aOR 1.34; 95% CI, 1.02–1.76). An estimated 25.9% and 43.5% of CS deliveries were attributable to maternal overweight and obesity. The highest estimated PARF for maternal overweight was in Syria (15.9%) and for obesity in Saudi Arabia (35.4%).

Limitations

Few included studies lacked standardized definitions or classifications of BMI and maternal weight, which may have affected comparability. Substantial heterogeneity was observed in subgroup analyses, requiring cautious interpretation of the pooled estimates.

Conclusions

Promoting healthy weight before and during pregnancy could reduce unnecessary and emergency CS deliveries, offering a critical intervention for improving maternal health.

Systematic review registration

PROSPERO CRD42024551878.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13643-025-03016-6.

Background

Cesarean section (CS) is a crucial lifesaving intervention when medically necessary; however, it may lead to both short- and long-term health risks for mothers and babies [1]. These risks, for instance, include respiratory distress and low Apgar scores in neonates [2, 3]. In the absence of a medical indication, CS can increase the likelihood of complications for both mother and child [4]. Over the past 30 years, the global use of CS has increased significantly, surpassing the recommended population-based rate of 10–15% [5]. CS rates have increased from approximately 7% in 1990 to 21% in 2021 [6], with a further rise expected in the coming decade. This upward trajectory is largely attributed to non-medically indicated CS deliveries. Importantly, studies have shown that CS rates above 20% do not lead to improved perinatal or neonatal outcomes. As such, the increasing trend of CS highlights the need for careful consideration to avoid unnecessary health risks [7].

A significant difference in the rate of CS among different countries and regions has been documented. Globally, the CS rate was more than 15% of total births in 106 and less than 10% in 48 countries between 2000 and 2015 [8]. Across various countries, the rate of CS deliveries varies from 0.6% in South Sudan to 58.1% in the Dominican Republic [8, 9]. Regionally, the MENA region has a higher CS rate than other regions, such as West and Central Africa, Eastern and Southern Africa, Latin America, and the Caribbean and South Asia [8]. This remarkable rise in the CS rate is attributed to an increase in the number of births and CS deliveries in private healthcare facilities among women with low obstetric risk [8].

Prepregnancy overweight and obesity increase the risk of complications such as gestational diabetes, cardiovascular diseases, cancer, diabetes, and hypertension, which may lead to increased possibilities of CS [10, 11]. Furthermore, overweight or obese women have nearly double the likelihood of undergoing CS delivery compared to normal weight women [12]. In the MENA region, obesity is an epidemic, and the prevalence is higher in women than men [13]. Since overweight and obesity are risk factors for CS delivery, the increasing prevalence of obesity may increase the rate of CS deliveries [12]. Therefore, it is vital that evidence reporting the relationship between maternal BMI and CS delivery is summarized. A systematic review and meta-analysis of 33 studies from 1980 to 2005 reported a crude pooled odds ratio (OR) of 1.46–2.89 for a CS delivery among overweight, obese, and severely obese women compared to normal weight women [14]. However, studies included in this review were from a single database (PubMed) and were conducted in America and Europe, not representing the MENA region. Another review of studies published from 1996 to 2007 reported that CS delivery risk is increased by 50% in overweight, more than double in obese, and 3.38 times more likely in morbidly obese compared to women with normal BMI [15].

While there has been growing research on factors influencing the risk of cesarean section (CS) delivery in the MENA region [16, 17], data synthesis on the relationship between maternal body mass index (BMI) and CS delivery remains limited. This systematic review and meta-analysis of observational studies conducted to provide a comprehensive assessment and quantify the strength of the association between maternal overweight and obesity and CS delivery. Additionally, the study estimated the proportion of CS deliveries attributable to maternal overweight and obesity, offering crucial insights for public health interventions targeting maternal health in the region.

Research contents and methods

This systematic review and meta-analysis were conducted following a registered protocol in the International Prospective Register of Systematic Reviews (PROSPERO, CRD42024551878, dated June 8, 2024). The review strictly adhered to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA 2020 statement) [18] (Additional file 1). All stages, including database searches, screening, eligibility assessment, data extraction, and quality appraisal, were performed independently by at least two reviewers, with discrepancies resolved by consensus or third-party adjudication. Random-effects models were used for meta-analyses to account for potential between-study heterogeneity, ensuring that the pooled estimates reflect both within- and between-study variability.

Search strategy, eligibility criteria, and information sources

A comprehensive literature search was conducted using key terms and MeSH headings related to maternal weight, cesarean section, and the MENA region. Six electronic databases (PubMed, Scopus, Embase, CINAHL, Web of Science, and Cochrane) were searched for studies published from January 2000 to January 2023, with an update on 14 November 2024. Reference lists were also manually screened (Additional file 2).

Primary studies reporting quantified or quantifiable associations between maternal BMI and cesarean delivery in any MENA country (as per WHO/EMR list) [19], regardless of publication language, were included. Excluded were qualitative studies, modeling studies, case reports/series, reviews, editorials, commentaries, letters, conference abstracts without accessible data, and studies lacking quantitative effect estimates. Also excluded were duplicate studies on the same population or those with contradictory or unverifiable estimates.

Study selection

All retrieved records were imported into Covidence software [20], and duplicates were removed. Titles/abstracts of records followed by full-text versions were screened independently by at least two of the four reviewers (J. F., S. M., S. Mo., Z. A.) against the pre-specified inclusion/exclusion criteria. Disagreements were resolved through discussion with a third reviewer (R. H. A.). Exclusion reasons are documented in the PRISMA flow diagram (Fig. 1).

Fig. 1.

PRISMA flow chart for selecting studies on maternal weight and cesarean section

Data extraction

A standardized template with predefined fields was used to ensure consistent data extraction. Two authors (J. F. and S. M.) independently extracted data, which was reviewed for accuracy by a third author (Z. A.). Discrepancies were resolved through discussion or consultation with a senior author (R. H. A. or B. A.). Extracted data included publication details (authors, year), study design, location, duration, setting, sample size, sampling strategy, and participant characteristics (age, BMI category, and pregnancy trimester at BMI measurement). Information on the mode of delivery, including gestational age at delivery and type of CS, was also recorded. Pre-quantified crude and adjusted effect estimates for the association between maternal BMI (continuous or categorical) and CS delivery, compared to normal BMI, were extracted along with 95% confidence intervals. Where available, effect estimates stratified by CS type (elective or emergency) and obesity class (I, II, III) were also collected. In studies where the association was not reported as a quantified estimate, raw data were extracted and used to calculate the effect estimate with their 95% confidence intervals (95% CI). In studies reporting crude odds ratios and with available crude data, the crude relative risk (RR) was quantified and utilized in the meta-analysis to generate weighted OR and RR.

Assessment of risk of bias

Quality assessment of included studies was conducted independently by at least two reviewers using the risk of bias (RoB). The 12 domains based on the National Institute of Health (NIH) quality assessment checklist for observational studies were used [21]. For a more robust evaluation, three additional RoB items were included: BMI ascertainment, sampling methodology, and sample size calculation. Each study was scored from 0 (high risk of bias) to 15 (low risk). Scores ≥ 12 indicated high quality, 7–11 moderate quality, and < 7 low quality.

Data synthesis

The characteristics of the included studies were narratively described and synthesized, reporting estimate ranges by type of exposure (overweight or obesity), effect estimate (crude [OR] or adjusted odds ratio [aOR] and RR), and CS delivery (elective or emergency). Weighted estimates of association and their corresponding 95% CIs were generated using the random-effects model. This model considers using the DerSimonian and Laird method, with the estimate of heterogeneity derived from the inverse-variance fixed-effect model [22]. Stratified estimates based on obesity subclass or other criteria were pooled using a random-effects model to generate a single composite estimate from each study. Similar stratified estimates across studies were pooled together to provide comprehensive stratum-specific insights on the strength of the association between the respective stratum (e.g., obesity class) and CS delivery. These pooled estimates were visually assessed using forest plots. Cochran’s Q statistic was used to test for evidence of heterogeneity, reporting the I-squared (I²) measure [23]. Tau-squared (τ²) was computed to estimate the between-study variance of the true association between maternal BMI and CS delivery and the 95% prediction interval to estimate the distribution of the true effect size among the included studies [23]. Meta-bias assessing the publication bias was reported using the funnel plots and supplemented with formal statistical testing using Egger’s test [24].

Attributable risk and population-attributable risk fraction

The attributable risk fraction (ARF) of CS delivery among overweight and obese women and the population-attributable risk fraction (PARF) for 18 MENA countries were estimated. Estimates were based on the generated pooled aORs and crude RRs derived from individual studies. These were used to quantify the proportion of CS deliveries attributable to maternal overweight and obesity, overall, and by CS type when available. Country-specific prevalence data of overweight and obesity among pregnant women informed PARF calculations using the pooled aORs for overweight and obese pregnant women.

Statistical analysis was performed using Stata SE 15 (Stata Corporation, College Station, TX, USA).

Results

Search results

The electronic search yielded 17,668 records, from which 6235 duplicates were removed. A total of 11,433 titles and abstracts were screened, followed by a full-text review of 155 articles. Ultimately, 45 studies met the eligibility criteria and were included in this systematic review [25–69] (Fig. 1).

Study characteristics

These studies were conducted across 12 countries in the MENA region, including Egypt (n = 2), Iran (n = 10), Iraq (n = 1), Jordan (n = 1), Lebanon (n = 3), Morocco (n = 2), Oman (n = 3), Pakistan (n = 3), Qatar (n = 6), Saudi Arabia (n = 8), Sudan (n = 1), and the United Arab Emirates (n = 3) (Fig. 2). Collectively, the included studies reported on 97,518 women who gave birth, with a total of 22,132 CS deliveries recorded in 42 studies. Three studies did not report the number of CS deliveries [30, 32, 56]. Of the total sample, 59,360 women (61.2%) were classified as overweight or obese (Table 1).

Fig. 2.

Geographical distribution of the 45 studies reported from 12 countries in the MENA region and included in the systematic review

Table 1.

Summary of the 45 research reports reporting on the association between various categories of maternal BMI and types of cesarean section delivery across the MENA region, illustrated by country

Author, year [Ref.]	Duration of data collection	Country, city	Design	Sampling strategy	Population	Sample size	With CS delivery	BMI category	C-section type	Estimate of association
										Type	Adjusted for	Magnitude (95% CI)
Ahmed M. M. et al., 2017 [25]	01 February 2016 to 28 February 2017	Egypt	Prospective cohort	Random	A total of 200 pregnant women with a mean age of 24.49 years and BMI ≥ 30 kg/m2 who presented to Kasr Al Ainy hospital in Egypt	200	113	Obese (BMI: ≥ 30 kg/m2)	Overall	Crude OR	–	1.87 (1.26–2.78)
										Crude RRc		1.38 (1.12–1.69)
Shaban M. M. et al., 2014 [26]	–	Egypt, Cairo	Cross-sectional	Random	A total of 235 pregnant obese women with mean BMI of 35.2 kg/m2	235	76	Obese (BMI: ≥ 30 kg/m2)	Overall	Crude OR	–	2.32 (1.56–3.43)
										Crude RRc		1.89 (1.40–2.55)
Mahnaz Z. et al., 2020 [27]	_	Iran, Shiraz	Cross-sectional	Consecutive	A total of 700 Iranian women of healthy and full-term infants (≥ 37 weeks) were recruited from five maternity hospitals	292	116	Overweight and/or obese — BMI ≥ 25 kg/m2	Elective CS	Adjusted OR	Age, education, employment status, maternity hospital, parity, diabetes, antenatal class, and infant birthweight	1.38 (1.01–1.88)
							110		Emergency CS			1.24 (0.90–1.69)
							116	Overweight and/or obese — BMI ≥ 25 kg/m2	Elective CS	Crude RRc		1.23 (1.01–1.50)
							110		Emergency CS			1.16 (0.94–1.42)
Maryam M. et al., 2019 [28]	06 July 2015 to 21 July 2015	Iran, Tehran	Cross-sectional	–	A study population of 4397 women who gave singleton birth in Tehran, Iran	1434	1081	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude OR	–	1.3 (1.12–1.51)
										Adjusted OR	Mother’s age and parity	1.21 (1.04–1.41)
						472	368	Obese (BMI: ≥ 30 kg/m2)	Overall	Crude OR	–	1.5 (1.18–1.9)
										Adjusted OR	Mother’s age and parity	1.35 (1.06–1.72)
						1434	1081	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude RRc	–	1.07 (1.03–1.11)
						472	368	Obese (BMI: ≥ 30 kg/m2)				1.11 (1.05–1.17)
Payam A. et al., 2018 [29]	06 July 2015 to 21 July 2015	Iran, Tehran	Cross-sectional	Whole population	A total of 4308 pregnant women with a mean age of 29 years and a mean BMI of 24.99 kg/m2 that had been referred to a maternity clinic in Iran	4308	3100	BMI — continuous variable	Overall	Crude OR	–	1.066 (1.05–1.09)
										Adjusted OR	Mother’s age, mother’s education, mother’s occupation, mother’s BMI, SES, parity, type of pregnancy, history of abortion, preeclampsia, ART, infant height, and baby’s head circumference	1.045 (1.03–1.07)
Hayedeh H. et al., 2018 [30]	01 September 2014 to 01 December 2016	Iran, Alborz	Cross-sectional	Random	A total of 1006 pregnant women with a mean age of 25.97 years and BMI ≥ 30 kg/m2	76	–	Obese (BMI: > 30 kg/m2)	Overall	Crude OR	–	1.4 (0.9–2.4)
										Adjusted OR	Age, parity, employment, and ethnicity	1.4 (0.8–2.3)
Saman M. et al., 2018 [31]	06 July 2015 to 21 July 2015	Iran, Tehran	Cross-sectional	Random	A total of 1529 pregnant women with a mean age of 28.25 years and a BMI of 24.49 kg/m2	2120	1529	BMI used as a continuous variable	Overall	Adjusted OR	Mothers’ age, mothers’ education, history of stillbirth, SES, infant weight, and baby’s head circumference	1.03 (0.99–1.075)
Manoochehr B., 2017 [32]	–	Iran, Gorgan	Cross-sectional	Random	A total of 612 singleton term pregnancies with a mean age of 25.08 years and a mean BMI of 27.37 kg/m2 that referred at ≤ 10 weeks of gestation to one of four public health care centers in rural areas in Iran	260	–	Overweight (BMI: 25.00–30 kg/m2)	Overall	Adjusted RR	Weight in early pregnancy, height, gestational age, parity, pre-term, history of abortion and stillbirth, smoking, alcohol, drug addiction, and chronic disease	1.52 (1.06–2.17) Urban
												1.49 (1.04–2.13) Rural
						116	–	Obese (BMI: ≥ 30 kg/m2)				1.74 (1.18–2.55) Urban
												1.62 (1.22–2.15) Rural
						260	–	Overweight pooled — urban and rural	Overall	Adjusted RR		1.51 (1.25–1.76)
						116	–	Obese Pooled—urban and rural				1.66 (1.43–1.89)
Afsaneh T. et al., 2017 [33]	2007 to 2011	Iran, Tehran	Prospective cohort	Consecutive	A total of 593 women in their first trimester of pregnancy with a mean age of 26.68 years	234	146	Overweight (≥ 25 kg/m2)	Overall	Crude RRc	–	1.07 (0.94–1.22)
Marzieh S. et al., 2016 [34]	01/10/2014 to 01/09/2015	Iran, Kermanshah	Prospective cohort	Sequential	A total of 370 pregnant women in their first trimester of pregnancy with a mean age of 24.1 years	120	20	Overweight (BMI: ≥ 25 kg/m2)	Overall	Crude OR	–	1.9 (0.94–4.16)
										Crude RRc		1.5 (0.81–2.88)
Hamideh P. et al., 2015 [35]	2010 to 2013	Iran, Kazvin	Retrospective cohort	Multiple cluster	A study population of 1376 pregnant women before their 12th week of pregnancy recruited from 5 different healthcare centers	422	197	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Adjusted OR	Age, education, and parity	1.35 (1.05–1.73)
						165	94	Obese (BMI: ≥ 30 kg/m2)				1.959 (1.37–2.79)
						422	197	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude RRc	–	1.17 (1.02–1.34)
						165	94	Obese (BMI: ≥ 30 kg/m2)				1.43 (1.21–1.68)
Zahra Y. et al., 2006 [36]	2002 to 2003	Iran, Urmia	Cross-sectional	–	A total of 270 women in their first 8 weeks of pregnancy with a mean age of 32.3 years	52	17	Overweight (BMI: 26.1–29 kg/m2)	Overall	Crude RRc	–	1.2 (0.75–1.93)
						48	18	Obese (BMI: > 29 kg/m2)				1.38 (0.88–2.18)
Waqar A. K. et al., 2014 [37]	01/01/2012 to 01/05/2012	Iraq, Baghdad	Cross-sectional	Convenience	A total of 404 pregnant women who presented to Al-Yarmouk Teaching Hospital in the city of Baghdad in Iraq	116	74	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude OR	–	17.34 (9.47–31.76)
						67	59	Obese (BMI: ≥ 30 kg/m2)				72.59 (30.2–174.4)
						116	74	Overweight (BMI: 25.00–29.9 kg/m2)		Crude RRc		6.92 (4.41–10.84)
						67	59	Obese (BMI: ≥ 30 kg/m2)				9.55 (6.17–14.78)
Sharief M. and Tareck A., 2000 [38]	01/12/1997 to 01/08/1998	Iraq, Basrah	Prospective cohort	–	A total of 40 pregnant women recruited from a maternity hospital with an age range of 19–42 years and parity between 2 and 4	40	3	BMI used as a continuous variable	Overall	Crude RRc	–	1.00 (0.23–4.37)
Eman F. B. et al., 2014 [39]	01 January 2009 to 31 December 2009	Jordan, Amman	Cross-sectional	Whole population	A total of 2129 Jordanian mothers with a mean age of 29.7 years	715	350	Overweight	Overall	Adjusted OR	Maternal age, parity, preexisting diabetes, preexisting hypertension, smoking, and gender of the baby	1.61 (1.32–1.97)
						715	166		Elective			3.39 (2.38–4.84)
						715	184		Emergency			1.84 (1.27–2.66)
						265	156	Obese	Overall			2.28 (1.71–3.04)
						265	93		Elective			1.81 (1.39–2.36)
						265	63		Emergency			1.55 (1.22–1.98)
						715	350	Overweight	Overall	Crude RRc	–	1.24 (1.11–1.38)
						715	166		Elective			1.51 (1.24–1.84)
						715	184		Emergency			1.06 (0.90–1.25)
						265	156	Obese	Overall			1.49 (1.31–1.69)
						265	93		Elective			2.29 (1.84–2.84)
						265	63		Emergency			0.98 (0.77–1.25)
Rouhana et al., 2023 [64]	–	Lebanon	Retrospective cohort	Random	A total of 683 pregnant women with a mean age of 31.15 years	163	91	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude OR	–	1.33 (0.92–1.94)
						175	52	Obese (BMI: ≥ 30 kg/m2)			–	2.38 (1.40–4.06)
Mayssa A. T. et al., 2021 [40]	01/01/2014 to 01/01/2016	Lebanon, Zgharta	Retrospective cohort	–	A total of 306 pregnant overweight women with a mean age of 18–34 years	344	116	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Adjusted OR	Weight gain, parity, age, income, educational level, parental jobs, residence, physical activity, and smoking habits	1.8 (1.2–2.7)
						306	174	Obese (BMI: ≥ 30 kg/m2)				2.1 (1.3–3.2)
						344	116	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude RRc	–	1.88 (1.51–2.34)
						306	174	Obese (BMI: ≥ 30 kg/m2)				3.17 (2.62–3.84)
Hala T. et al., 2007 [41]	01/01/2001 to 12/01/2002	Lebanon, Beirut	Cross-sectional	Consecutive	A total of 18,837 infants born at 9 hospitals from the National Collaborative Perinatal Neonatal Network (NCPNN)	5128	1376	Overweight (BMI: 26–29 kg/m2)	Overall	Crude OR	–	1.5 (0.7–3.1)
						5151	1746	Obese (BMI > 29 kg/m2)				2.1 (1.0–4.4)
						5128	1376	Overweight (BMI: 26–29 kg/m2)	Overall	Crude RRc	–	1.18 (1.10–1.28)
						5151	1746	Obese (BMI > 29 kg/m2)				1.50 (1.40–1.61)
								Overweight (BMI: 26–29 kg/m2)	Overall	Adjusted OR	Age, paternal occupation, mode of payment, parity, birth weight, prematurity, multiple gestation, care during pregnancy, hospital, and year	1.90 (0.80–4.30)
								Obese (BMI > 29 kg/m2)				2.7 (1.2–6.1)
Samim S. et al., 2024 [69]	November 2021 to December 2022	Morocco	Cross-sectional	Convenience	A total of 400 parturient women aged 18 years and over with singleton pregnancies	119	38	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude OR	–	1.27 (0.74–2.17)
						126	66	Obese ≥ 30 kg/m2			–	2.98 (1.79–4.97)
Latifa M. et al., 2013 [42]	10/01/2010 to 10/01/2011	Morocco, Benslimane	Cross-sectional	Consecutive	Pregnant Moroccan women in their first trimester with an average age of 30 years old who presented to the hospital’s maternity department	348	43	Overweight (BMI: 25.0–29.9 kg/m2)	Overall	Crude OR	–	1.17 (0.79–1.71)
						87	23	Obese (BMI: ≥ 30 kg/m2)				2.97 (1.76–5.01)
						348	43	Overweight (BMI: 25.0–29.9 kg/m2)		Crude RR		1.15 (0.81–1.61)
						87	23	Obese (BMI: ≥ 30 kg/m2)				2.5 (1.64–3.65)
Anita Z. et al., 2018 [43]	01/11/2011 to 01/04/2012	Oman, Muscat	Retrospective cohort	Whole population	A total of 2652 pregnant Omani women with available weight/height or BMI data at < 12 gestational weeks	440	66	Obese (BMI: ≥ 30 kg/m2)	Overall	Crude RR	–	1.48 (1.08–2.03)
Fatma M. A. et al., 2016 [44]	01/03/2011 to 01/04/2012	Oman, Muscat	Prospective cohort	Consecutive	Pregnant Omani women in their first trimester with an average age of 29 years old and who presented to the primary health care center	201	31	Overweight (BMI: 25.0–29.9 kg/m2)	Overall	Crude RR	–	1.4 (0.9–2.3)
						206	43	Obese (BMI: ≥ 30 kg/m2)				1.9 (1.2–3.0)
						155	8	Overweight (BMI: 25.0–29.9 kg/m2)	Elective	Crude RR	–	4.6 (1.0–21.4)
						144	12	Obese (BMI: ≥ 30 kg/m2)				7.5 (1.7–32.8)
						185	23	Overweight (BMI: 25.0–29.9 kg/m2)	Emergency	Crude RR	–	1.2 (0.6–2.0)
						182	31	Obese (BMI: ≥ 30 kg/m2)				1.6 (1.0–2.7)
Ibrahim A. B. et al., 2012 [45]	01/01/2009 to 01/03/2009	Oman	Case control	Random	A total of 500 pregnant women where 250 had cesarean section and 250 had vaginal deliveries among selected Obstetrics and Gynecology Departments of four hospitals in Oman	84	36	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Adjusted OR	Age, education, family income, diabetes mellitus, number of previous cesarean deliveries, parity, and birth spacing in the past	1.93 (0.94–3.97)
						83	58	Obese (BMI: > 30 kg/m2)				2.11 (1.04–4.3)
						84	36	Overweight (BMI: 25.00–29.9 kg/m2)		Crude RRc		0.97 (0.70–1.34)
						83	58	Obese (BMI: > 30 kg/m2)				1.59 (1.23–2.05)
Rafia G. et al., 2020 [46]	01/11/2018 to 01/10/2019	Pakistan, Lahore	Cross-sectional	–	A total of 2766 mother-neonate pairs who presented to the Department of Neonatology	910	705	Overweight (BMI: ≥ 25.00–29.9 kg/m2)	Overall	Crude OR	–	1.4 (1.15–1.7)
						456	344	Obese (BMI: ≥ 30 kg/m2)				1.25 (0.98–1.6)
						910	705	Overweight (BMI: ≥ 25.00–29.9 kg/m2)	Overall	Crude RRc		1.09 (1.04–1.15)
						456	344	Obese (BMI: ≥ 30 kg/m2)				1.06 (0.99–1.13)
Farheen Y. et al., 2016 [47]	01 January 2012 to 31 December 2012	Pakistan, Karachi	Retrospective cohort	–	A total of 183 pregnant women in their first trimester with a mean age of 27.61 years	81	47	Normal BMI = < 22.9 High BMI = > 23kg/m2	Overall	Crude OR		1.95 (1.09–3.57)
										Adjusted OR	Age, parity, reasons for induction of labor, hypertension, and diabetes mellitus	1.45 (0.72–2.92)
										Crude RRc	–	1.41 (1.05–1.90)
Shama M. and Humaira M., 2012 [48]	01/02/2003 to 01/02/2007	Pakistan, Karachi	Retrospective cohort	–	A total of 4735 Pakistani pregnant women with a mean age of 28.2 years	1344	311	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude OR	–	0.97 (0.83–1.14)
						1044	290	Obese (BMI: ≥ 30 kg/m2)				1.24 (1.05–1.47)
						1044	290	Obese (BMI: ≥ 30 kg/m2)		Adjusted OR	Ethnicity, age, parity, working status, and prepregnancy BMI	1.44 (1.17–1.78)
						1344	311	Overweight (BMI: 25.00–29.9 kg/m2)		Crude RRc	–	0.98 (0.87–1.11)
						1044	290	Obese (BMI: ≥ 30 kg/m2)				1.18 (1.04–1.33)
Habiba S. A. and Nida L., 2011 [49]	01/06/2009 to 01/06/2010	Pakistan	Cross-sectional	–	A total of 412 pregnant women with a parity of 0 to 5 coming for antenatal care during the first 3 months of pregnancy	120	58	Obese (BMI: ≥ 25 kg/m2)	Overall	Crude RRc	–	1.3 (1.03–1.66)
Minisha F. et al., 2023 [65]	01/01/2017 to 01/12/2020	Qatar	Retrospective cohort	Whole population	A total of 7044 women having singleton live births beyond 24 weeks of gestation, classified into 2 class IV obesity (BMI ≥ 50 kg/m2) and normal/overweight	247	143	Class IV obesity (BMI ≥ 50 kg/m2)	Overall	Crude OR	–	4.64 (3.58–6.01)
									Overall	Adjusted OR	Maternal age, parity, previous cesarean section, preexisting diabetes, hypertension, asthma, thyroid disease, and history of bariatric surgery	3.19 (2.26–4.5)
Lawand G. et al., 2023 [66]	01/01/2017 to 01/12/2017	Qatar	Retrospective cohort	Whole population	A total of 14,624 women having singleton births were categorized as underweight, overweight, obesity class I, obesity class II, and obesity class III and compared to those with normal BMI	5033	1465	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Adjusted OR	Age and parity categories, previous caesarean, pre-existing diabetes, and chronic hypertension	1.31 (1.16–1.48)
						3665	1327	Class I obesity (30 to < 35)				1.55 (1.36–1.77)
						1561	632	Class II obesity (35 to < 40)				1.96 (1.66–2.31)
						637	299	Class III (severe or fatal) — BMI: ≥ 40 kg/m2)				2.33 (1.85–2.94)
Al-Dewik N. A. I. et al., 2024 [67]	01 January 2017 to 31 December 2017	Qatar	Retrospective cohort	Whole population	A total of 6212 women who had singleton pregnancies and who had or had not (n = 315) undergone bariatric surgery	1953	624	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude OR	–	1.5 (1.30–1.72)
										Adjusted OR	Nationality, maternal age, DM, parity, and ethnicity	1.25 (1.06–1.48)
						1918	792	Obese ≥ 30 kg/m2		Crude OR	–	2.24 (1.96–2.57)
										Adjusted OR	Nationality, maternal age, DM, parity, and ethnicity	1.77 (1.49–2.11)
Shazia S. and Ula N., 2019 [50]	–	Qatar	Retrospective cohort	–	A total of 1134 nulliparous women of 50 nationalities (classified into Arab and non-Arab ethnicity) in Qatar	399	107	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude OR	–	1.48 (1.07–2.06)
						230	69	Obese (BMI: ≥ 30 kg/m2)				1.74 (1.19–2.52)
						399	107	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude RRc		1.35 (1.05–1.75)
						230	69	Obese (BMI: ≥ 30 kg/m2)				1.52 (1.15–2.00)
Mohammed B. et al., 2018 [51]	01/03/2015 to 12/01/2016	Qatar, Doha	Retrospective cohort	Whole population	A total of 1838 pregnant women with type 2 diabetes mellitus who attended the pregnancy clinic	383	239	Overweight and/or obese (combined group)	Overall	Crude OR	–	1.05 (1.01–1.08)
										Adjusted OR	Maternal age, pre-pregnancy, BMI and gestational weight gain, first trimester HbA1C (%)	1.05 (1.01–1.09)
							239			Crude RRc	–	1.79 (1.61–1.98)
Abu Yaacob S. et al., 2002 [52]	January 01, 2001 to June 30, 2001	Qatar, Doha	Prospective cohort	Random	A total of 276 pregnant women who presented to the maternity hospital based in Qatar	75	22	Obese (BMI: > 30 kg/m2)	Overall	Crude RRc	–	2.2 (1.12–4.32)
							16		Elective			2.67 (1.10–6.44)
							6		Emergency			1.5 (0.44–5.10)
Alshammari R. et al., 2023 [68]	01 October 2021 to 31 May 2022	Saudi Arabia	Retrospective cohort	Whole population	A total of 500 pregnant Saudi women who delivered a single neonate at a gestation age of 28 weeks	99	33	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude OR	–	0.42 (0.19–0.92)
						151	66	Class I obesity (30 to < 35)				0.65 (0.31–1.37)
						117	61	Class II obesity (35 to < 40)				0.92 (0.43–1.96)
						94	60	Class III (severe or fatal) — BMI: ≥ 40 kg/m2)				1.49 (0.68–3.26)
Hanan A. et al., 2021 [53]	12 January 2017 to 01 January 2018	Saudi Arabia, Riyad	Cross-sectional	Convenience	A total of 524 Saudi women who are currently or were previously pregnant and presented to different clinics of King Khalid University Hospital	142	42	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude OR	–	1.0 (0.57–1.78)
						112	39	Class I obesity (BMI: 30 to < 35 kg/m2)				1.28 (0.71–2.3)
						43	13	Class II obesity (BMI: 35 to < 40 kg/m2)				1.04 (0.47–2.28)
						32	15	Class III obesity (BMI: ≥ 40 kg/m2)				2.11 (0.93–4.81)
						142	42	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude RRc	–	1.004 (0.67–1.5)
						112	39	Class I obesity (BMI: 30 to < 35 kg/m2)				1.18 (0.79–1.76)
						43	13	Class II obesity (BMI: 35 to < 40 kg/m2)				1.03 (0.59–1.78)
						32	15	Class III obesity (BMI: ≥ 40 kg/m2)				1.59 (0.98–2.58)
Hayfaa W. et al., 2021 [54]	–	Saudi Arabia, Riyadh	Retrospective cohort	–	A total of 7029 Saudi pregnant women recruited from 3 hospitals	2338	148	Overweight (BMI: 25.00–29.9 kg/m2)	Elective	Crude OR	–	1.32 (1.01–1.7)
						2447	305	Obese (BMI: ≥ 30 kg/m2)				2.77 (2.2–3.5)
						2338	148	Overweight (BMI: 25.00–29.9 kg/m2)	Elective	Crude RRc		1.30 (1.01–1.66)
						2447	305	Obese (BMI: ≥ 30 kg/m2)				2.55 (2.05–3.17)
						2338	303	Overweight (BMI: 25.00–29.9 kg/m2)	Emergency	Crude OR	–	1.15 (0.96–1.37)
						2447	396	Obese (BMI: ≥ 30 kg/m2)				1.49 (1.26–1.78)
						2338	303	Overweight (BMI: 25.00–29.9 kg/m2)	Emergency	RRc		1.13 (0.97–1.33)
						2447	396	Obese (BMI: ≥ 30 kg/m2)				1.41 (1.22–1.64)
						2338	148	Overweight (BMI: 25.00–29.9 kg/m2)	Emergency	Adjusted OR	Maternal age, gestational age, parity	1.25 (1.03–1.50)
						2447	305	Obese (BMI: ≥ 30 kg/m2)				1.67 (1.39–2.01)
Nahla K. I. et al., 2020 [55]	–	Saudi Arabia, Jeddah	Case control	Random	A total of 300 pregnant women with a mean age of 30.09 years who presented to an Obstetrics & Gynecology Department in Saudi Arabia	227	123	Overweight and/or obese (combined group)	Overall	Crude OR	–	2.25 (1.23–4.1)
										Crude RRc		1.57 (1.08–2.28)
Muneera A., 2018 [56]	01/08/2016 to 01/10/2016	Saudi Arabia, Qassim	Cross-sectional	Convenience	A total of 936 pregnant women with an average age of 29 years who presented to the Maternity and Children’s Hospital (MCH), Buraidah, in Saudi Arabia	345	–	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude OR	–	1.38 (0.87–2.19)
						216		Obese (BMI: (≥ 30 kg/m2)				2.3 (1.51–3.48)
						207		Class III obesity				3.48 (2.16–5.6)
Yasmeen A. H., 2017 [57]	01/01/2012 to 01/12/2014	Saudi Arabia, Al-Khobar	Prospective cohort	–	A total of 300 pregnant patients in their first trimester with a BMI ≥ 29.9 kg/m2 and 300 nonobese pregnant females with a BMI < 29.9 kg/m2	300	99	Obese (BMI: ≥ 30 kg/m2)	Overall	Adjusted OR	Not specified	2.5 (1.3–5.6)
						300	99	Obese (BMI: ≥ 30 kg/m2)		Crude RRc	–	2.2 (1.61–3.01)
Abdel-Hady E. G. and Sabry H., 2010 [58]	–	Saudi Arabia, Al-Hassa	Prospective cohort	Whole population	A total of 787 pregnant women who presented to the antenatal care during the first month of pregnancy	187	21	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude RR	–	1.2 (0.6–2.0)
						226	43	Obese (BMI: ≥ 30 kg/m2)				2.0 (1.3–3.0)
Meher N. et al., 2009 [59]	01/11/2008 to 01/06/2009	Saudi Arabia, Buraida	Prospective cohort	Random	A study population of 1000 pregnant Saudi females randomly selected from the outpatient and emergency departments	331	49	Overweight (BMI: 25.00–29.5 kg/m2)	Overall	Crude RRc	–	3.06 (1.75–5.34)
						300	48	Obese (BMI: 30 to 39.9 kg/m2)				3.31 (1.89–5.78)
						39	9	Morbidly obese (BMI: ≥ 40 kg/m2)				4.78 (2.24–10.16)
Duria A. R. et al., 2011 [60]	01 February 2008 to 30 April 2008	Sudan, Khartoum	Cross-sectional	–	A total of 1574 Sudanese pregnant women with a mean age of 27.7 years	597	308	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Adjusted OR	Age, parity, education, and prenatal care	1.7 (1.4–2.2)
						215	130	Class I obesity (BMI: 30 to < 35 kg/m2)				2.50 (1.80–3.40)
						108	71	Class II obesity (BMI: 35 to < 40 kg/m2)				3.10 (2.00–4.80)
						597	308	Overweight (BMI: 25.00–29.9 kg/m2)		Crude RRc	–	1.37 (1.21–1.56)
						215	130	Class I obesity (BMI: 30 to < 35 kg/m2)				1.61 (1.39–1.86)
						108	71	Class II obesity (BMI: 35 to < 40 kg/m2)				1.75 (1.48–2.07)
Zainab T. et al., 2019 [61]	01/03/2017 to 01/09/2017	United Arab Emirates, Abu Dhabi	Cross-sectional	Random	A total of 1624 UAE nationals and nonnational women in their breastfeeding phase with a mean age of 30.1 years and a mean BMI of 23.9 kg/m2	1624	491	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Adjusted OR	Age, parent education, occupation, child gender, marital status, gestational age, and nationality	1.1 (0.85–1.42)
								Obese (BMI: ≥ 30 kg/m2)				1.79 (1.15–2.79)
Pooja R. V. and Lekshmi B., 2012 [62]	01/12/2010 to 01/10/2011	United Arab Emirates, Abu Dhabi	Retrospective cohort	–	A total of 1985 women with singleton pregnancies recruited from a tertiary care government referral hospital	635	103	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Adjusted OR	Age, parity, hypertension and diabetes, antenatal complications, labor and delivery complications, and neonatal outcomes	1.07 (0.76–1.52)
						520	103	Class I obesity (BMI: 30 to < 35 kg/m2)				1.51 (1.05–2.19)
						280	73	Class II obesity (BMI: 35 to < 40 kg/m2)				2.09 (1.38–3.17)
						130	37	Class III obesity (BMI: ≥ 40 kg/m2)				2.73 (1.61–4.65)
						635	32	Overweight (BMI: 25.00–29.9 kg/m2)	Elective	Adjusted OR	Age, parity, hypertension and diabetes, antenatal complications, labor and delivery complications, and neonatal outcomes	1.06 (0.59–1.89)
						520	40	Class I obesity (BMI: 30 to < 35 kg/m2)				1.80 (1.01–3.19)
						280	33	Class II obesity (BMI: 35 to < 40 kg/m2)				3.43 (1.89–6.31)
						130	16	Class III obesity (BMI: ≥ 40 kg/m2)				3.22 (1.50–6.91)
						930	89	Obese (pooled: Classes I–III)				2.74 (2.37–3.10)
						635	71	Overweight (BMI: 25.00–29.9 kg/m2)	Emergency	Adjusted OR	Age, parity, hypertension and diabetes, antenatal complications, labor and delivery complications, and neonatal outcomes	1.06 (0.70–1.61)
						520	63	Class I obesity (BMI: 30 to < 35 kg/m2)				1.26 (0.81–1.96)
						280	40	Class II obesity (BMI: 35 to < 40 kg/m2)				1.24 (0.74–2.08)
						130	21	Class III obesity (BMI: ≥ 40 kg/m2)				1.99 (1.05–3.79)
						930	124	Obese (pooled class I–III)				1.41 (1.11–1.71)
						635	103	Overweight (BMI: 25.00–29.9 kg/m2)	Overall	Crude RRc	–	Overall 1.05 (0.79–1.39)
						520	103	Class I obesity (BMI: 30 to < 35 kg/m2)				1.28 (0.96–1.70)
						280	73	Class II obesity (BMI: 35 to < 40 kg/m2)				1.68 (1.25–2.27)
						130	37	Class III obesity (BMI: ≥ 40 kg/m2)				1.84 (1.29–2.62)
						635	32	Overweight (BMI: 25.00–29.9 kg/m2)	Elective	Crude RRc	–	1.06 (0.61–1.82)
						520	40	Class I obesity (BMI: 30 to < 35 kg/m2)				1.62 (0.96–2.72)
						280	33	Class II obesity (BMI: 35 to < 40 kg/m2)				2.48 (1.45–4.22)
						130	16	Class III obesity (BMI: ≥ 40 kg/m2)				2.58 (1.38–4.84)
						635	71	Overweight (BMI: 25.00–29.9 kg/m2)	Emergency	Crude RRc	–	1.04 (0.73–1.48)
						520	63	Class I obesity (BMI: 30 to < 35 kg/m2)				1.13 (0.79–1.62)
						280	40	Class II obesity (BMI: 35 to < 40 kg/m2)				1.33 (0.90–1.99)
						130	21	Class III obesity (BMI: ≥ 40 kg/m2)				1.51 (0.93–2.43)
A. S. Kumari, 2000 [63]	1996 to 1998	United Arab Emirates, Abu Dhabi	Retrospective cohort	Whole population	A total of 188 obese women with BMI equal to or more than 40 kg/m2 and a mean age of 31.66 years	188	18	Class III (BMI: ≥ 40 kg/m2)	Elective	Crude OR	–	3.4 (1.5–7.8)
						188	18		Emergency			1.6 (0.8–3.1)
						188	36		Overall			2.3 (1.4–3.9)
						188	18	Class III (BMI: ≥ 40 kg/m2)	Elective	Crude RRc	–	3.19 (1.47–6.95)
						188	18		Emergency			1.51 (0.82–2.81)
						188	36		Overall			2.05 (1.30–3.25)

OR odds ratio, RR relative risk, RRc converted pre-calculated crude odds ratio into relative risk or directly calculated the relative risk from crude data reported in the study

Of the 45 included studies, 18 were cross-sectional [26–32, 36, 37, 39, 41, 42, 46, 49, 53, 56, 60, 61], 15 were retrospective cohort [35, 40, 43, 47, 48, 50, 51, 54, 62–68], 9 were prospective cohort [25, 33, 34, 38, 44, 52, 57–59], and 2 were case-control studies [45, 55]. All included studies were conducted in clinical settings with pregnant women recruited from maternity hospitals, clinics, and health centers. The main sampling method used was random sampling in 11 out of the 45 studies [25, 26, 30–32, 45, 52, 55, 59, 61] (Table 1).

Primary outcome: CS delivery

Association between BMI categories and CS delivery

All included studies reported an overall estimate for CS delivery, and seven provided estimates based on the type of CS (elective or emergency) [27, 39, 44, 52, 54, 62, 63]. A total of 32 studies reported estimates for maternal overweight, 30 studies provided estimates for maternal obesity, 3 studies reported estimates for combined overweight and obesity [27, 51, 55], and 8 studies reported estimates for different classes of maternal obesity and CS delivery [53, 56, 60, 62, 63, 65, 66, 68].

A total of 187 crude and adjusted estimates were extracted or calculated to assess the association between various maternal BMI categories and CS delivery (Table 1). The highest crude ORs for the association between maternal BMI and CS delivery, compared to normal BMI, were 17.34 (95% CI 9.47–31.76) for overweight and 72.59 (95% CI 30.2–174.4) for obesity [37]. The lowest crude ORs were 0.42 (95% CI 0.19–0.92) for overweight, 0.65 (95% CI 0.31–1.37) for class I obesity, 0.92 (95% CI 0.43–1.96) for class II obesity, and 1.49 (95% CI 0.68–3.26) for class III obesity [68]. The highest crude RRs were 6.92 (95% CI 4.41–10.84) for overweight and 9.55 (95% CI 6.17–14.78) for obesity [37]. The lowest crude RRs were 0.97 (95% CI 0.70–1.34) for overweight [45] and 1.06 (95% CI 0.99–1.13) for obesity [46]. The highest adjusted ORs were 1.93 (95% CI 0.94–3.97) for overweight [45], 2.70 (95% CI 1.2–6.1) for obesity [41], and 3.19 (95% CI 2.26–4.50) for class IV obesity [65]. The lowest adjusted ORs were 1.07 (95% CI 0.76–1.52) for overweight [62] and 1.35 (95% CI 1.06–1.72) for obesity [28]. Adjusted RRs from a study in Iran were 1.51 (95% CI 1.25–1.76) for overweight and 1.66 (95% CI 1.43–1.89) for obesity [32] (Table 1).

Weighted estimates of association between BMI categories and CS delivery

Compared to normal BMI, maternal overweight or obesity was associated with 1.46 (95% CI 1.19–1.78) and 2.20 (95% CI 1.74–2.79) times increased likelihood of CS (Fig. 3). Pooling adjusted individuals’ estimates for various potential confounders, the likelihood of CS was 1.35 (95% CI 1.24–1.49) and 1.77 (95% CI 1.49–2.11) times higher among maternal overweight and obese women, respectively, and 1.61 times (95% CI 1.37–1.90) for both overweight and obese (Fig. 4). After excluding one adjusted estimate of one case-control study [45], the likelihood of CS delivery due to maternal overweight and obesity was 1.36 times (95% CI 1.21–1.52) and 1.91 times (95% CI 1.58–2.32), respectively, with an overall 1.62 times (95% CI 1.35–1.93) increased likelihood of CS delivery among overweight and obese women (see Fig. S1 in Additional file 3). The unadjusted probability of CS increased by 27.0% (RR 1.27, 95% CI 1.17–1.37) for overweight, 76.0% (RR 1.76, 95% CI 1.54–2.02) for obesity, and 77.0% (RR 1.77, 95% CI 1.61–1.96) for both overweight and obesity (Fig. 5). In one study reporting adjusted relative risk [32], maternal overweight and obesity combined were associated with a 60% higher likelihood of cesarean delivery compared to normal BMI (aRR 1.60; 95% CI 1.43–1.78) (see Fig. S2 in Additional file 3).

Fig. 3.

Forest plot depicting crude odds ratio estimating the strength of association between overweight and obesity with C-section (crude odds ratio)

Fig. 4.

Forest plot depicting the adjusted odds ratio estimating strength of association between overweight and obesity with CS delivery

Fig. 5.

Forest plot depicting crude relative risk estimating strength of association between overweight and obesity with CS delivery

Subgroup meta-analyses

Maternal overweight was associated with a 35% increased risk of elective CS delivery (aRR 1.35; 95% CI 1.17–1.56) and a 26% increased risk of emergency CS delivery (RR 1.26; 95% CI 1.05–1.51) (Table 2, Fig. S7). Similarly, maternal obesity increased the risk of elective CS by 80% (RR 1.80; 95% CI 1.12–2.69) and emergency CS by 26% (RR 1.26; 95% CI 1.04–1.52), with an overall 49% higher risk of cesarean delivery across both types (RR 1.49; 95% CI 1.19–1.86) (Table 2, Fig. S9).

Table 2.

Summary pooled estimates of association between BMI categories and different types of C-section delivery, illustrated by type of the association estimate

Exposure-outcome pair	Estimate type	Studies included	Estimates range	Pooled weighted estimate (95% CI)	p-value	Heterogeneity index		Predictive interval (95% CI)	Additional file 3
						Chi-squared	I2, %
BMI (kg/m2)—continuous	OR	1	1.07 (1.05–1.09)	–	–	–	–	–	S3
	RR	1	1.0 (0.23–4.37)	–	–	–	–	–	S4
	aOR	2	1.05–1.03	1.04 (1.02–1.06)	0.524	0.41	NE	NE	S5
	aRR	0	–	–	–	–	–	–	–
Overweight—elective CS	OR	0	–	–	–	–	–	–	–
	RR	5	1.06–4.60	1.35 (1.17–1.56)	0.186	6.18	35.2	0.92–1.98	S7
	aOR	2	1.06–3.39	1.94 (0.62–6.06)	0.001	11.17	91.0	NE	S8
	aRR	0	–	–	–	–	–	–	–
Overweight—emergency CS	OR	1	1.15 (0.96–1.37)	–	–	–	–	–	S6
	RR	4	1.04–1.51	1.26 (1.05–1.51)	0.200	4.64	35.4	0.67–2.37	S7
	aOR	3	1.06–1.84	1.34 (1.02–1.76)	0.106	4.49	55.5	0.33–7.43	S8
	aRR	0	–	–	–	–	–	–	–
Obesity—elective CS	OR	1	2.77 (2.20–3.50)	–	–	–	–	–	S8
	RR	6	1.06–7.5	1.80 (1.20–2.69)	< 0.001	56.7	91.1	0.48–6.78	S9
	aOR	2	1.81–2.74	2.26 (1.51–3.39)	0.006	7.50	86.7	NE	S10
	aRR	0	–	–	–	–	–	–	–
Obesity—emergency CS	OR	1	1.49 (1.26–1.78)	–	–	–	–	–	S8
	RR	5	0.98–1.60	1.26 (1.04–1.52)	0.127	7.17	44.2	0.74–2.15	S9
	aOR	4	1.24–1.67	1.51 (1.34–1.69)	0.380	3.08	2.6	0.66–4.37	S10
	aRR	0	–	–	–	–	–	–	–
Obesity class
Class I obesity	OR	2	0.65–1.28	0.95 (0.49–1.84)	–	–	–	–	S11
	RR	4	1.18–3.31	1.58 (1.18–2.13)	0.013	10.84	72.3	0.46–5.48	S12
	aOR	3	1.51–2.50	1.78 (1.32–2.41)	0.022	7.65	73.8	NE	S13
	aRR	0	–	–	–	–	–	–	–
Class II obesity	OR	2	0.92–1.04	0.98 (0.56–1.69)	–	–	–	–	S11
	RR	4	1.03–4.78	1.79 (1.27–2.52)	0.016	10.38	71.1	0.43–7.37	S12
	aOR	3	1.96–3.10	2.21 (1.71–2.84)	0.158	3.69	45.8	0.17–28.8	S13
	aRR	0	–	–	–	–	–	–	–
Class III obesity	OR	5	1.49–3.48	2.84 (1.87–4.31)	0.000	4.90	69.5	0.71–11.41	S11
	RR	3	1.59–2.05	1.83 (1.43–2.33)	0.755	0.56	0.0	0.38–2.64	S12
	aOR	3	2.33–2.73	2.61 (2.14–3.18)	0.325	2.25	10.9	0.58–11.8	S13
	aRR	0	–	–	–	–	–	–	–
Class I obesity—elective CS	OR	0	–	–	–	–	–	–	–
	RR	1	1.62 (0.96–2.72)	–	–	–	–	–	S15
	aOR	2	1.80–1.38	1.47 (1.11–1.93)	0.426	0.63	0.00	NE	S16
	aRR	0	–	–	–	–	–	–	–
Class II obesity—elective CS	OR	0	–	–	–	–	–	–	–
	RR	1	2.48 (1.45–4.22)	–	–	–	–	–	S15
	aOR	1	3.43 (1.89–6.31)	–	–	–	–	–	S16
	aRR	0	–	–	–	–	–	–	–
Class III obesity—elective CS	OR	1	3.40 (1.50–7.80)	–	–	–	–	–	S14
	RR	2	2.58–3.19	2.81 (1.72–4.57)	0.677	0.17	0.0	NE	S15
	aOR	1	3.22 (1.51–6.91)	–	–	–	–	–	S16
	aRR	0	–	–	–	–	–	–	–
Class I obesity—emergency CS	OR	0	–	–	–	–	–	–	–
	RR	1	1.33 (0.90–1.99)	–	–	–	–	–	–
	aOR	1	1.26 (0.81–1.96)	–	–	–	–	–	S18
	aRR	0	–	–	–	–	–	–	–
Class II obesity—emergency CS	OR	0	–	–	–	–	–	–	–
	RR	1	1.51 (0.93–2.43)	–	–	–	–	–	S18
	aOR	1	1.24 (0.74–2.08)	–	–	–	–	–	S19
	aRR	0	–	–	–	–	–	–	–
Class III obesity—emergency CS	OR	1	1.60 (0.80–3.10)	–	–	–	–	–	S17
	RR	2	1.51–1.51	1.51 (0.91–2.11)	1.00	0.00	0.0	NE	S18
	aOR	1	1.99 (1.05–3.79)	–	–	–	–	–	S19
	aRR	0	–	–	–	–	–	–	–

Pooling adjusted estimates accounting for potential confounders, maternal overweight was associated with a 1.94-fold (95% CI 0.62–6.06) and 1.34-fold (95% CI 1.02–1.76) increased likelihood of elective and emergency cesarean delivery, respectively (Table 2, Fig. S8). Maternal obesity was associated with a 2.26-fold (95% CI 1.51–3.39) and 1.51-fold (95% CI 1.34–1.69) increased likelihood of elective and emergency cesarean delivery, respectively (Table 2, Fig. S10). Regarding obesity classes, the pooled crude RR for CS delivery was 1.58 (95% CI 1.18–2.13) for class I, 1.79 (95% CI 1.27–2.52) for class II, and 1.83 (95% CI 1.43–2.33) for class III (Table 2, Fig. S12). The corresponding pooled adjusted ORs were 1.78 (95% CI 1.32–2.41) for class I, 2.21 (95% CI 1.71–2.84) for class II, and 2.61 (95% CI 2.14–3.18) for class III (Table 2, Fig. S13). A comprehensive summary of pooled crude and adjusted RRs and ORs for all subgroups is provided in Table 2 and Appendix 2 (Figs. S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, S16, S17, S18, S19).

Risk fraction

ARF of CS by maternal BMI category

The pooled adjusted effect estimate for the association between maternal overweight and CS delivery was 1.35 and 1.77 for obesity. Based on these estimates, the attributable fractions of CS deliveries among overweight and obese women were 25.9% and 43.5%, respectively. Furthermore, a class-effect increase was observed in the proportion of CS deliveries across obesity classes, with the attributable fractions of CS deliveries among women with class I, II, and III obesity estimated at 43.8%, 54.7%, and 61.7%, respectively, and at 43.8% for both overweight and obese women. Of the 6356 and 5117 CS deliveries among overweight and obese women, an estimated 1646 and 2225 cases, respectively, were potentially attributable to maternal overweight and obesity (see Table S1 in Additional file 4).

PARF by maternal BMI category

The proportion of CS deliveries attributable to maternal overweight was highest in Syria (15.9%), Libya (15.5%), and Sudan (15.1%) and lowest in Jordan (3.1%). For maternal obesity, the highest PARFs were observed in Saudi Arabia (35.4%), Kuwait (31.5%), and the United Arab Emirates (30.1%), with the lowest in Jordan (1.8%) (see Table S2 in Additional file 4).

Risk of bias

All studies included in this systematic review were assessed for quality across 15 risk-of-bias (RoB) domains. All 45 studies clearly stated their research objectives. Maternal BMI was ascertained via direct measurement or from medical records in 42 studies. The mean RoB score was 12 (out of a maximum of 15), with scores ranging from 9 to 14. Based on these scores, 31 studies (68.9%) were classified as high quality (score ≥ 12) and 14 as moderate quality (score 9–11). The distribution of studies categorized as having low, moderate, or high RoB across each assessment domain is shown in Fig. 20 in Additional file 3.

Publication bias

Irrespective of the type of reported estimate, the generated funnel plots and statistical tests revealed evidence of potential publication bias and small-study effects (Egger’s test, p < 0.001) influencing the pooled estimates of association (see Fig. S21 in Additional file 3). The asymmetry observed in the funnel plot suggests that smaller studies with nonsignificant or negative results are likely underrepresented in the published literature. Such selective publication or outcome reporting can artificially inflate pooled effect sizes, thereby overestimating the true magnitude of the association between maternal BMI and cesarean section delivery.

The presence of publication bias is a well-recognized challenge in meta-analyses of observational studies, particularly in regions where research dissemination may be influenced by language, resource constraints, or selective journal indexing. To enhance future evidence synthesis, efforts should be made to include a broader spectrum of data sources beyond peer-reviewed journals. This includes gray literature, institutional and governmental health reports, regional registries, and postgraduate theses, which often contain null or unfavorable findings. Incorporating such sources would reduce the risk of reporting bias, improve the representativeness of the evidence base, and increase the robustness and generalizability of pooled estimates.

Discussion

Summary of main findings

This systematic review and meta-analysis comprehensively evaluated the association between overweight and obesity during pregnancy and the risk of CS delivery in the MENA region. The review also estimated the number of CS deliveries attributed to maternal overweight and obesity among the included overweight and obese women and among the general population of pregnant women in different countries in the MENA region. Pooling crude and adjusted estimates of association, we found that both overweight and obese pregnant women had significantly higher odds of undergoing CS compared to women with normal BMI. The risk increased progressively with higher maternal BMI categories (i.e., greater in obese than in overweight women). Overweight and obese women have significantly higher odds of CS, with obesity showing a more pronounced effect. Pooled estimates reveal a 1.46-fold increased likelihood of CS for overweight women and a 2.20-fold increase for obese women. Class-specific effects show a stepwise increase in CS delivery with higher BMI categories, particularly in women with class III obesity. Subgroup analyses indicate that both elective and emergency CS deliveries are influenced by maternal BMI, with obesity especially linked to a higher risk of elective CS.

In this review, we also found that a substantial proportion of CS deliveries was found to be attributable to maternal overweight and obesity, both among overweight and obese women themselves and at the population level, across all pregnant women in the included MENA countries. The population-attributable fractions varied by country, reflecting differences in the prevalence of maternal overweight and obesity as well as CS delivery practices in the region.

The findings highlight a preventable burden of CS deliveries linked to maternal excess weight, underscoring the importance of targeted preconception and antenatal weight management strategies in the MENA region. Due to the lack of studies from several countries in the MENA region, findings from our systematic review and meta-analysis lack generalizability to all MENA countries. However, the prediction interval allows us to consider the risk and type of CS delivery among overweight and obese women.

Our findings are consistent with a previous meta-analysis of global estimates of the association between maternal weight and CS, from studies published between 2000 and 2005, showing that compared to normal BMI, maternal overweight, obesity, and severe obesity are associated with 46%, 105%, and 189% increased risk of CS, respectively [70]. Another meta-analysis estimated the risk of CS types (elective, emergency) among maternal overweight, obese, and morbidly obese nulliparous women to be 53%, 126%, and 238% for elective CS, respectively, and 64% and 123% for emergency CS, among overweight and obese women, respectively [15]. Although this is also seen in the MENA region, the risk of CS associated with maternal overweight and obesity is lower compared to the global level. This difference may be attributed to unique sociocultural and healthcare system factors within the region, such as variations in clinical decision-making or maternal care practices [71]. Recent studies have shown stronger associations than observed in our MENA-related estimates. For example, a study from Peru found that obese women had an 81% increased CS risk [72]. Furthermore, a large-scale meta-analysis involving over 20 million pregnancies worldwide reported that maternal obesity was associated with a 2.15-fold increased risk of CS [73].

The differences in the strength of association between maternal weight and CS at the global versus MENA level may reflect variations in clinical practice, access to maternity services, and thresholds for recommending elective CS across healthcare systems [74]. Cultural attitudes toward childbirth and maternal healthcare-seeking behavior may also influence these patterns [71], highlighting the need to interpret our findings within their local context. Since maternal overweight and obesity are modifiable risk factors, there is a clear opportunity for intervention through preconception counseling, targeted antenatal care, and lifestyle-based weight management programs [75]. Also, educating women on the risks of excessive weight gain before and during pregnancy, paired with accessible support for healthy eating and physical activity, could help reduce CS rates, especially elective ones [76]. Therefore, it is highly recommended that healthcare systems in the MENA region update clinical guidelines that consider local population risks and evidence-based thresholds for recommending CS [77]. Training clinicians to adopt a more standardized, risk-based approach may minimize unnecessary procedures and improve maternal and neonatal outcomes [78]. As CS rates are projected to rise globally, potentially exceeding 48% in North Africa by 2030 [79], our findings highlight the urgency of preventive strategies tailored to the MENA region. These strategies may integrate clinical, behavioral, and policy-level responses to address both maternal obesity and the overuse of CS.

Limitations and strengths

Some limitations should be acknowledged when interpreting the present findings. Inconsistencies in BMI classification criteria and the timing of BMI assessment in some of the included studies represent an important limitation. While most studies adopted the WHO’s BMI thresholds for overweight and obesity, others used country-specific or unstated criteria, introducing potential misclassification bias. Furthermore, BMI measurements were taken at varying stages—before conception, during early pregnancy, or in later trimesters—each reflecting different physiological states and degrees of gestational weight change. These methodological inconsistencies limit cross-study comparability and may partially explain the observed heterogeneity. Future research should adopt standardized BMI definitions and prioritize prepregnancy or early gestational measurements to improve the validity and comparability of regional evidence.

Another methodological limitation pertains to the inconsistent adjustment for potential confounders across included studies. Although several studies controlled the effect of key factors such as maternal age, parity, and comorbidities, others reported only crude associations without multivariable adjustment. This variability may have resulted in residual confounding, leading to over- or underestimation of the true relationship between maternal BMI and CS delivery. Future primary studies should adopt standardized adjustment models that include sociodemographic factors, obstetric history, and medical conditions to yield more accurate and comparable estimates.

The variability in methodological quality among the included studies represents an additional limitation. Although most studies were rated as high quality based on the NIH RoB assessment, a notable proportion were classified as moderate or low quality. These studies often lacked clear descriptions of sampling procedures, BMI ascertainment methods, or adjustment for confounding variables, which could have introduced bias and affected the precision of pooled estimates. The inclusion of such studies, while necessary to capture the full scope of available evidence in the MENA region, may have weakened the overall strength of the conclusions.

A further limitation that involves the lack of data from several MENA countries represents a notable limitation that restricts the generalizability of our findings to the entire region. Most of the included studies originated from countries with well-established health research infrastructures, such as Saudi Arabia, Iran, and Qatar, while limited or no data were available from other nations, particularly those in North Africa and parts of the Levant. Consequently, the pooled estimates may disproportionately reflect countries with stronger surveillance and reporting systems.

Substantial heterogeneity observed across the included studies represents an important limitation that may influence the precision and interpretability of the pooled estimates. This heterogeneity likely arises from multiple methodological and contextual factors, including variations in study design, population demographics, sample size, healthcare setting, and analytical approaches. Differences in BMI assessment methods, particularly the timing of measurement (pre-pregnancy, early gestation, or at delivery), and inconsistent adjustment for key confounders, such as maternal age, parity, and comorbidities, further contributed to the observed variability.

Although subgroup analyses were conducted to explore potential sources of heterogeneity, including obesity class, CS type (elective versus emergency), and adjustment level, these analyses only partially accounted for the observed variation. This residual heterogeneity underscores the complex and multifactorial nature of the relationship between maternal BMI and CS delivery in the MENA region. Future meta-analyses should incorporate advanced analytical techniques such as meta-regression or hierarchical modeling to systematically assess study-level characteristics and contextual factors contributing to heterogeneity. Strengthening data standardization, improving methodological rigor, and enhancing reporting transparency in primary studies will also be essential to reduce heterogeneity and improve the reliability and generalizability of pooled regional estimates. Furthermore, the absence of data from several MENA countries limits the generalizability of the findings to the entire region.

The quantified ARFs and PARFs provide valuable insights into the proportion of CS deliveries linked to maternal overweight and obesity; however, these estimates are based on several underlying assumptions that may limit their robustness. The presence of substantial between-study heterogeneity, variability in BMI assessment methods, and differences in healthcare practices across countries could have influenced the accuracy of the pooled effect estimates used in these calculations. Moreover, incomplete data coverage from several MENA countries may have restricted the representativeness of regional population prevalence estimates, thereby affecting the precision of the derived PARFs. Consequently, these findings should be interpreted as approximate indicators of the potential burden rather than exact quantifications. Future analyses incorporating meta-regression models, nationally representative datasets, and harmonized data collection methods would enhance the robustness and interpretability of attributable risk estimates across the region.

Despite the acknowledged potential limitations, this systematic review has several strengths. The review followed a registered protocol on PROSPERO [80]. It is the first comprehensive and systematic effort to review, analyze, and synthesize evidence on the association between maternal weight and CS delivery in the MENA region. The systematic review was conducted using a rigorous and transparent methodology, with at least two independent reviewers involved at each stage of the process, minimizing potential bias and enhancing reliability. The meta-analysis incorporated various types of pooled effect estimates that were adjusted for key confounders, including maternal age and parity, thereby enhancing the accuracy and validity of the findings. Moreover, by pooling both relative risks and odds ratios, the analysis provides complementary insights, capturing both the probability and the likelihood of undergoing cesarean delivery, respectively, rather than relying on a single type of effect estimate. The inclusion of many studies and participants allowed for robust meta-analyses, yielding precise and stable estimates, as evidenced by narrow confidence intervals. To assess the robustness of the results, a sensitivity analysis was conducted by excluding two case-control studies, which further reinforced the consistency and strength of the observed associations. Importantly, this review goes beyond overall associations by providing country-specific estimates of the proportion of CS deliveries potentially attributable to maternal overweight and obesity, both among women with excess weight and in the general pregnant population. It also offers stratified analyses by BMI categories and type of CS (elective versus emergency), based on the level of detail reported in the original studies. Furthermore, the quality and risk of bias of the included studies were systematically evaluated using a well-established and validated risk of bias assessment tool, ensuring that the synthesized evidence is both credible and contextually relevant for guiding maternal health policies and interventions across the region.

Implications for practice and future research

This systematic review and meta-analysis confirm that elevated maternal BMI is a major determinant of CS delivery in the MENA region, with both overweight and obesity significantly increasing the likelihood of elective and emergency CS. These findings emphasize the pressing need for regionally tailored strategies aimed at promoting optimal maternal weight before and during pregnancy.

While consistent with global evidence, the present review provides novel region-specific insights by highlighting contextual drivers that may underline the observed associations in the MENA region. Factors such as the high and rising prevalence of overweight and obesity among women of reproductive age, rapid urbanization, and the expanding role of the private healthcare sector likely contribute to the escalating CS rates. Additionally, sociocultural preferences for elective CS delivery, variable clinical decision-making thresholds, and limited access to standardized antenatal counseling appear to reinforce these trends.

Despite the acknowledged potential limitations, these regionally distinctive findings underscore the importance of integrating cultural, socioeconomic, and healthcare system considerations into maternal health interventions. Efforts should focus on implementing evidence-based, context-sensitive programs that promote preconception counseling, healthy gestational weight gain, and equitable access to high-quality maternity care. Future research should also aim to elucidate the complex interplay between lifestyle, clinical practice, and systemic factors contributing to maternal obesity and CS delivery in the region. Such work will be critical for informing sustainable policies and practice guidelines designed to mitigate the burden of obesity-related cesarean deliveries and improve maternal and neonatal outcomes across the MENA region.

Conclusion

This review of 45 observational studies from 12 countries in the MENA region found a strong association between maternal overweight and obesity and CS delivery. In particular, increased obesity class was found to be associated with an increased likelihood of emergency CS delivery. The review also estimated that one-quarter of and nearly 44.0% of CS deliveries among overweight and obese women were attributable to overweight and obesity. Findings would provide insights necessary for creating tailored interventions aimed at managing maternal weight before and during pregnancy, ultimately decreasing the risk of CS delivery and enhancing outcomes for both mothers and newborns.

Authors’ contributions

RHA conceptualized and designed the study. LÖ designed and reviewed the database search strategies. ZA, JF, and SAM assessed the eligibility of the retrieved citations in the titles/abstracts and full-text screening phases. JF and SAM extracted data and assessed the quality of the included studies. ZA and SM cross-checked the extracted data. RHA performed the meta-analyses. RHA, BA, and ZA drafted the initial draft of the manuscript. All authors contributed to the article and approved the submitted version.

Funding

This study was supported by a research grant from the College of Medicine and Health Sciences, United Arab Emirates University (fund code: 31M472). The funder had no role in the study design, data collection, analysis, interpretation, or manuscript preparation.

Data availability

The original data utilized in the study are included in the article and additional files. Further inquiries can be directed to the corresponding author.

Declarations

Ethics approval and consent to participate

Not applicable. This manuscript does not contain any data involving individual human participants in any form. The review is based solely on previously published data from peer-reviewed journals. As such, ethical approval and informed consent were not required.

Competing interests

Nothing declared.