Skip to main content
NCBI home page
Indian Journal of Endocrinology and Metabolism logoLink to Indian Journal of Endocrinology and Metabolism
. 2025 Jul 11;29(4):381–393. doi: 10.4103/ijem.ijem_140_25

Hypoglycaemia During Oral Glucose Tolerance Test in Pregnancy and Feto-Maternal Outcomes: A Systematic Review and Meta-Analysis

Deep Dutta 1,✉, Manoj Kumar 2, Radhika Jindal 3, Ameya Joshi 4, Abul B M Kamrul-Hasan 5, Saptarshi Bhattacharya 6
PMCID: PMC12410962  PMID: 40917325

Abstract

The significance of hypoglycaemia during oral glucose tolerance tests (OGTT) in pregnancy is uncertain. This systematic review and meta-analysis (SRM) evaluated if hypoglycaemia during OGTT predicts feto-maternal outcomes. Electronic databases were searched for studies in pregnancy where an OGTT at 24–28 weeks was done and feto-maternal outcomes were documented. Hypoglycaemia during OGTT (reactive hypoglycaemia) was defined as blood glucose < 90 mg/dl or less than the fasting-glucose value. Primary outcomes were the occurrence of small-for-gestational-age (SGA) and neonatal intensive-care unit (NICU) admission. Secondary outcomes were birthweight, macrosomia, large-for-gestational-age (LGA), gestational age at delivery (GA), 5-minute Apgar score (5AS), caesarean section (CS), and pregnancy-induced hypertension (PIH). Association of hypoglycaemia with pre-pregnancy maternal weight, maternal weight gain during pregnancy, and maternal age was noted. PRISMA guidelines were followed, and the preestablished protocol was registered on PROSPERO (CRD42025644556). From initially screened 448 articles, data from 13 articles involving 30,462 women were analysed. Compared to normoglycemia, hypoglycaemia during OGTT was associated with significantly higher SGA [OR1.81;95%CI1.31-2.50; P = .0003], higher NICU admission [OR 1.44; 95% CI 1.17–1.76; P < .001; I2 = 0%], lower birthweight [MD-68.38g; 95%CI -126.25- -10.52; P = .020], lower macrosomia [OR 0.60;95%CI 0.42-0.86;P < .005], higher 5AS <8 [OR2.53;95%CI1.37-4.68; P = .003], lower CS [OR 0.82;95%CI0.75-0.90; P < .0001], lower maternal pre-pregnancy weight [MD -4.90 kg; 95%CI 9.17-0.62; P = .02; I2 = 75%] and higher gestational-hypertension [OR 1.31; 95%CI 1.03 –1.66;P = .030]. The rates of SGA, LGA, 5AS <8, and maternal age were similar in women with hypoglycaemia and gestational diabetes. Hypoglycaemia during OGTT is associated with gestational hypertension, lower birthweight, increased SGA, higher NICU admission, and higher 5AS <8. Lower maternal pre-pregnancy weight was a predictor of hypoglycaemia during OGTT.

Keywords: Hypoglycaemia, maternal outcomes, neonatal outcomes, pregnancy

INTRODUCTION

Pregnancy is a state of physiologic glucose intolerance and hyperinsulinemia that can manifest as different degrees of dysglycaemia, including reactive hypoglycaemia (RH).[1] Traditionally, screening for gestational diabetes (GDM) is done between 24 and 28 weeks of gestation using an oral glucose tolerance test (OGTT), coinciding with a surge in insulin resistance secondary to hormonal alterations.[2] With the increasing prevalence of obesity and insulin resistance, OGTT is increasingly being done before 20 weeks of gestation, leading to early diagnosis of GDM.[3] Hyperglycaemia throughout pregnancy has been linked with adverse feto-maternal outcomes.[4] Hence, traditionally the focus has been on picking up hyperglycaemia during OGTT.

Hypoglycaemia during OGTT is not uncommon, having a prevalence of 3.6–11.3%.[5,6] The definition for hypoglycaemia during OGTT (RH) has not been uniform in literature, ranging from blood glucose (BG) values less than 45–90 mg/dL.[7] It has been suggested that hypoglycaemia during OGTT (RH) in pregnancy be defined as BG level lower after glucose load compared with fasting BG values.[8] The mechanisms for RH during OGTT is not well understood, likely multifactorial, with hyperinsulinism and loss of first-phase insulin release being key components.[9] An associated increased second-phase insulin release may result in RH during OGTT in pregnancy.[9] Several studies have been published evaluating feto-materal outcomes with RH in pregnancy during OGTT.[5,6] However, a systematic-review has not been conducted to assess if hypoglycaemia during OGTT in pregnancy is linked to feto-maternal outcomes. Hence we undertook this study to address this knowledge gap following the PRISMA guidelines.[10]

METHODS

We conducted an extensive literature search across databases including PubMed, Ovid Embase, Ovid Medline, Cochrane Library, ClinicalTrials.gov, CNKI, ctri.nic.in, and Google Scholar. All studies published up to February 2025 were examined. The search strategy utilized combinations of key terms such as “hypoglycaemia” “hypoglycemia,” “reactive hypoglycemia” along with “glucose tolerance test”, “oral glucose tolerance test” and “pregnancy” Additionally, reference lists of relevant studies were reviewed to identify further publications.

Eligibility criteria

The PICOS criteria were utilized to screen and select the studies. The population (P) included women with pregnancy who underwent OGTT. The intervention (I) comprised of women with pregnancy who were documented to have hypoglycaemia during OGTT (reactive hypoglycaemia), defined as 1-hour or 2-hour post-glucose (OGTT) blood glucose < 90 mg/dl or less than the fasting blood glucose value. The control (C) group comprised women with pregnancy who did not have hypoglycaemia during OGTT. The outcomes (O) focused on adverse neonatal and maternal outcomes. The study type (S) comprised of randomized controlled trials (RCTs), cohort studies and case-control studies. Cross-sectional studies, case reports, case series, reviews, expert opinions, editorials, letters to the editor, and duplicate reports were excluded from the analysis. Bariatric surgery prior to pregnancy has been associated with increased occurrence of dumping syndrome and reactive hypoglycaemia during pregnancy.[11] Hence studies having pregnant women with prior history of bariatric surgery were excluded. Additionally, studies focusing solely on multi-fetal pregnancies or those lacking sufficient information to assess methods or data analysis were excluded. Duplicates were removed before screening articles by title and abstract, followed by full-text screening to confirm eligibility.

Study outcomes

The primary outcomes analysed were small for gestational age (SGA) and need for NICU admission. The secondary neonatal outcomes examined were birth weight (g), occurrence of large for gestational age (LGA), macrosomia and 5 minute Apgar score (5AS) <8. LGA refers to a birth weight above the 90th percentile or more than 2 standard deviations (SDs) above the mean for a specific gestational age.[12] Macrosomia has been defined as a birth-weight of ≥ 4000 g or ≥ 4500 g in the literature.[13] For analysis in our SRM, we have included participants based on the prespecified definition of macrosomia in the respective studies. When both the cut-offs for macrosomia were provided in a trial, we used the lower cut-off of 4000 g. The secondary maternal outcomes were gestational age at the time of childbirth (weeks), need for caesarean section (CS), maternal pre-pregnancy body weight, weight gain during pregnancy, hypertension in pregnancy and preterm birth (<37 weeks of gestation).

Study selection

Two reviewers independently screened the titles and abstracts of the identified studies. The full text was reviewed if a study could not be excluded based on the title and abstract alone. Any disagreements regarding the study’s eligibility were resolved by consulting a third author.

Data synthesis

The data analysis focused on prespecified outcomes, comparing 2 groups: pregnant women detected to have hypoglycaemia during OGTT (intervention group) and pregnant women without hypoglycaemia during OGTT (control group). Pooled effect estimates with corresponding 95% confidence intervals (CIs) were calculated. Forest plots were generated for visualization, and meta-analysis tests were performed using random effects models. Dichotomous outcomes, such as treatment success, were reported as odds ratio (OR) with 95% CIs. Adverse events were presented as absolute risk differences post-treatment. Heterogeneity was assessed using the prediction interval, and Higgin’s I2 test. Thresholds for I² values were defined as follows: 25% for low heterogeneity, 50% for moderate heterogeneity, and 75% for high heterogeneity.[14] When a particular meta-analysis showed high levels of heterogeneity between studies, the prediction interval was used to see how much variation in effect sizes might be expected in new studies.[15] A prediction interval analysis helps us to understand how much variability exists across different study populations, potentially highlighting limitations of the current analysis.[15] RevMan Web (Cochrane Collaboration UK 2025) was used to compare the primary and secondary outcomes between the intervention and control groups. A P value < .050 was considered statistically significant.

Methodological quality and certainty of evidence

The risk of bias in the included studies was meticulously evaluated by 2 independent reviewers. The Cochrane Risk of Bias Tool, version 2, was employed to assess potential biases in RCTs, focusing on key domains such as randomization processes, deviations from intended interventions, incomplete outcome data, measurement of outcomes, and selective reporting.[16] The Newcastle-Ottawa scale was employed to study the risk of bias of the cohort studies.[17]

RESULTS

An initial search yielded 448 articles. After removing 30 duplicates, the remaining 418 articles were subjected to title screening, narrowing the selection to 103 articles. The abstracts of these 103 studies were further reviewed, resulting in 19 articles of interest. A comprehensive review of these 19 articles was done, and we found 13 articles involving 30,462 women with pregnancy, which evaluated the impact of hypoglycaemia during OGTT in pregnancy on feto-maternal outcomes.[5,6,8,18,19,20,21,22,23,24,25,26] The details have been elaborated in Figure 1.

Figure 1.

Figure 1

Open in a new tab

Flowchart elaborating on study retrieval and inclusion in this systematic review

Study characteristics

The characteristics of the patients evaluated in different studies analysed in our SRM have been elaborated in Table 1. Different definitions of hypoglycaemia during OGTT (reactive hypoglycaemia) were used in different studies. One study, four studies, two studies, one study, two studies, one study and one study defined hypoglycaemia during OGTT (reactive hypoglycaemia) as BG <90 mg/dl,[24] <88 mg/dl,[7,20,21,22] <70 mg/dl,[17,19] <63 mg/dl,[25] <60 mg/dl,[6,23] <50 mg/dl,[18] and <45 mg/dl[5] respectively. In the study by Rehman et al.,[8] hypoglycaemia during OGTT (reactive hypoglycaemia) was defined as blood glucose value less than the fasting glucose value.

Table 1.

Characteristics of the patients in different studies analysed in this systematic review

Author; year; Country Type of study OGTT details; Hypoglycaemia definition used for study group Inclusion Criteria Exclusion Criteria Hypoglycaemia Group (n) Normoglycaemia Group (n) Gestational diabetes group (n)
Bayraktar 2020; Turkey[18] Retrospective study 2-h 75-g OGTT (WHO & IADPSG criteria); post-glucose BG <70 mg/dl Included women in 24th –28th gestational weeks Aged <19 or >35 years, multiple pregnancies, delivery before 24th gestational week & <500-g newborn; diabetes 71 554 0
Blunt 2024; UK[19] Retrospective study 2-h 75-g OGTT (WHO & IADPSG criteria); post-glucose BG <70 mg/dl Included women in 24th –28th gestational weeks Multiple pregnancies, pre-existing diabetes 120 39 41
Budak 2018; Turkey[25] Retrospective study 50-g OGTT 1hBG ≥140 mg/dl, followed by 100-g or 75-g OGTT; post-glucose BG <90 mg/dl Included women in 24th –28th gestational weeks Multiple pregnancies, pre-existing diabetes 312 1712 0
Calfee 1999; USA[24] Prospective study 50-g OGTT 1hBG ≥140 mg/dl, followed by 100-g OGTT (ACOG criteria); post-glucose BG <88 mg/dl Singleton pregnancies, >=24 weeks gestation Multiple pregnancies, pre-existing diabetes 116 248 0
Delibas 2018; Turkey[5] Retrospective study 50-g OGTT 1hBG ≥140 mg/dl, followed by 100-g OGTT (ACOG criteria); post-glucose BG <45 mg/dL (2.5 mmol/L) Singleton pregnancies, >=24 weeks gestation Multiple pregnancies, pre-existing diabetes, incomplete records, multiple OGTTs done 15 316 82
Feinberg 2009; USA[23] Retrospective study 50-g OGTT 1 hBG ≥140 mg/dl, followed by 100-g OGTT (ACOG criteria); post-glucose BG <88 mg/dl Early pregnancy & 24th–28th weeks gestation screening Women with confirmed GDM following OGTT, diabetes, multiple OGTTs done in the same pregnancy 334 334 0
Haggiag 2024; Israel[7] Retrospective study 50-g OGTT 1hBG ≥140 mg/dl, followed by 100-g OGTT (Carpenter & Coustan criteria); post-glucose <60 mg/dl 24th–28th weeks gestation Multiple pregnancies, diabetes 2367 11025 1730
Pugh 2009; USA[21] Retrospective study 50-g OGTT 1hBG ≥140 mg/dl, followed by 100-g OGTT; 1 hBG <88 mg/dl 24th–28th weeks gestation - 436 434 0
Raviv 2017; Israel[6] Retrospective study 2-h 75-g OGTT; post-glucose BG <60 mg/dl 24th–28th weeks gestation Preterm deliveries (<34 weeks), multiple pregnancies and major anomalies 216 1072 791
Rehman 2025; UK[8] Retrospective study 2-h 75-g OGTT; post-glucose BG <fasting BG value 24th–28th weeks gestation Multiple pregnancies, diabetes 417 400 681
Topcu 2017; Turkey[22] Retrospective study 50-g OGTT; 1 hBG <88 mg/dl 24th–28th weeks gestation Multiple pregnancies, diabetes 2091 2091 0
Weissman 2005; Israel[20] Retrospective study 50-g OGTT 1 hBG ≥140 mg/dl, followed by 100-g OGTT; post-glucose BG <50 mg/dl 24th–28th weeks gestation Multiple pregnancies, diabetes; past history of GDM 46 538 0
Yuen 2019; Australia[26] Prospective study 2-h 75-g OGTT (WHO criteria); post-glucose BG <63 mg/dl 24th–28th weeks gestation Multiple pregnancies, diabetes; past history of GDM 52 1249 532
Open in a new tab

OGTT: oral glucose tolerance test; BG: blood glucose; 1hBG: 1-hour blood glucose; GDM: gestational diabetes; WHO: world health organization; IADPSG; International Association of the Diabetes and Pregnancy Study Groups; ACOG: American College of Obstetrics & Gynaecology; n: number of participants

Risk of bias and quality assessment of the included studies

The summary of the risk of bias of the cohort studies is elaborated in Supplementary Table 1. The Newcastle-Ottawa Scale (NOS) assessments indicate that all the studies had a low risk of bias, with scores ranging from 8 to 9 out of 9.

Hypoglycaemia vs. normoglycaemia during glucose tolerance test

Primary outcomes

Five studies, including 4852 participants, reported SGA. Women who had hypoglycaemia during OGTT had a significantly higher occurrence of SGA childbirth [OR 1.81; 95%CI 1.31-2.50; P < .001; I2 = 0%; Figure 2a]. A predictive interval of the effect size (1.31 to 2.50) complemented the significant impact on the mean effect size [Figure 2a]. Eight studies, including 6323 participants, reported the need for NICU admission. Children born to women who had hypoglycaemia during OGTT had significantly higher need for NICU admission after childbirth [OR 1.44; 95%CI 1.17-1.76; P < .001; I2 = 0%; Figure 2b]. A predictive interval of the effect size (1.17 to 1.76) complemented the significant impact on the mean effect size [Figure 2b].

Figure 2.

Figure 2

Open in a new tab

Forest plot highlighting the impact of hypoglycaemia during oral glucose tolerance test (OGTT) as compared to those having normoglycaemia during OGTT on (a) Small for gestational age (SGA); (b) need for intensive care unit (NICU) admission; (c) Birthweight; (d) Large for gestational age (LGA); (e) Macrosomia; (f) 5-minute Apgar score <8

Secondary outcomes

Neonatal outcomes

Nine studies, including 7848 participants, reported on birth weight. Children born to women who had hypoglycaemia during OGTT had significantly lower birthweight [Mean Difference (MD) -68.38 g; 95%CI -126.25 - -10.52; P = .020; I2 = 71%; Figure 2c]. A predictive interval of the effect size was significantly larger (−214.11 to 77.34g) due to the presence of data heterogeneity [Figure 2c]. Five studies, including 3698 participants, reported on LGA. Children born to women who had hypoglycaemia during OGTT had lower chances of having LGA, but statistically not significant [OR 0.68; 95%CI 0.44–1.05; P = .080; I2 = 28%; Figure 2d]. A predictive interval of the effect size was similar and not significant (0.35–1.32) [Figure 2d]. Four studies, including 3367 participants, reported on macrosomia. Children born to women who had hypoglycaemia during OGTT had significantly lower chances of having macrosomia [OR 0.60; 95%CI 0.42-0.86; P = .005; I2 = 0%; Figure 2e]. A predictive interval of the effect size (0.42–0.86) complemented the significant impact on the mean effect size [Figure 2e]. Seven studies, including 6887 participants, reported on the 5-minute Apgar score of < 8 in the newborn. Children born to women who had hypoglycaemia during OGTT had significantly higher chances of having a 5-minute Apgar score < 8 [OR 2.53; 95%CI 1.37–4.68; P = .003; I2 = 19%; Figure 2f]. A predictive interval of the effect size (1.00–6.42) complemented the significant impact on the mean effect size [Figure 2f].

Maternal outcomes

Ten studies, including 23,875 participants, reported on maternal age at the time of pregnancy. Women who had hypoglycaemia during OGTT had an age comparable to mothers who had normoglycaemia during OGTT [MD -.63 years; 95%CI -1.47 –.21; P = .140; I2 = 95%; Figure 3a]. A predictive interval of the effect size was significantly larger (-3.16 to 1.91 years) and was not statistically significant due to the presence of significant data heterogeneity [Figure 3a]. Eleven studies, including 13,113 participants, reported on the need for caesarean section for delivery. Women who had hypoglycaemia during OGTT had significantly lower need for caesarean section as compared to women who had normoglycaemia during OGTT [OR 0.82; 95%CI 0.75-0.90; P < .001; I2 = 0%; Figure 3b]. A predictive interval of the effect size (0.75–0.90) complemented the significant impact on the mean effect size [Figure 3b]. Ten studies, including 25,172 participants, reported on gestational age at the time of childbirth. Women who had hypoglycaemia during OGTT had similar gestational age compared to mothers who had normoglycaemia during OGTT [MD -.03 weeks; 95%CI -.18 -.13; P = .750; I2 = 77%; Figure 3c]. A predictive interval of the effect size was significantly larger (-.44 to. 39 weeks) due to the presence of significant data heterogeneity [Figure 3c]. Four studies, including 3926 participants, reported on maternal weight gain during pregnancy. Women who had hypoglycaemia during OGTT had higher weight gain during pregnancy, but not statistically significant [MD.25 kg; 95%CI -.07 -.58; P = .130; I2 = 7%; Figure 3d]. A predictive interval of the effect size was significantly larger (−0.12 to 0.63 kg) due to data heterogeneity [Figure 3d]. Two studies, including 1234 participants, reported on maternal pre-pregnancy weight. Women who had hypoglycaemia during OGTT had significantly lower maternal pre-pregnancy weight [MD -4.90 kg; 95%CI 9.17 –.62; P = .020; I2 = 75%; Figure 3e]. A predictive interval of the effect size was significantly larger (−11.77 to 1.97 kg) and not significant due to the presence of significant data heterogeneity [Figure 3e]. Four studies, including 17,165 participants, reported on maternal hypertension during pregnancy. Women who had hypoglycaemia during OGTT had a higher occurrence of hypertension during pregnancy [OR 1.31; 95%CI 1.03 – 1.66; P = .030; I2 = 0%; Figure 3f]. A predictive interval of the effect size (1.03–1.66) complemented the significant impact on the mean effect size [Figure 3f].

Figure 3.

Figure 3

Open in a new tab

Forest plot highlighting the impact of hypoglycaemia during oral glucose tolerance test (OGTT) as compared to those having normoglycaemia during OGTT on (a) maternal age; (b) need for caesarean section; (c) Gestational age at the time of childbirth; (d) Weight gain during pregnancy; (e) Maternal pre-pregnancy weight; (f) Hypertension during pregnancy

Hypoglycaemia vs hyperglycaemia (gestational diabetes) during glucose tolerance test

Two studies, including 1104 participants, reported on SGA and LGA. As compared to women with GDM, women who had hypoglycaemia during OGTT had similar SGA [OR 1.56; 95%CI.39 – 6.31; P = .530; I2 = 65%; Figure 4a] and LGA [OR 1.01; 95%CI.68 – 1.50; P = .970; I2 = 0%; Figure 4b]. Three studies, including 1921 participants, reported on Apgar score at 5 min < 8. As compared to women with GDM, children born to women who had hypoglycaemia during OGTT had similar Apgar score at 5 min <8 [OR 2.35; 95%CI.27 – 20.41; P = .441; I2 = 66%; Figure 4c].

Figure 4.

Figure 4

Open in a new tab

Forest plot highlighting the impact of hypoglycaemia during oral glucose tolerance test (OGTT) as compared to those having gestational diabetes during OGTT on (a) Small for gestational age (SGA); (b) Large for gestational age (LGA); (c) 5 minute Apgar score <8; (d) Maternal age; (e) Need for caesarean section Macrosomia; (f) Gestational age at the time of childbirth

Four studies, including 4939 participants, report on maternal age. As compared to women with GDM, women who have hypoglycaemia during OGTT had similar age [MD -1.75 years; 95%CI -4.24 – 0.74; P = .170; I2 = 93%; Figure 4d]. A predictive interval of the effect size was larger for maternal age (-7.06 to 3.56 years), and the analysis lost its clinical significance. Five studies, including 2666 participants, reported on the need for caesarean section. As compared to women with GDM, women who have hypoglycaemia during OGTT had significantly lower need for caesarean section [OR 0.53; 95%CI.37 –.78; P = .001; I2 = 56%; Figure 4e]. A predictive interval of the effect size was significantly larger (−0.27 to 1.07) and not significant due to the presence of data heterogeneity Figure 4e).

Five studies, including 6602 participants, reported on gestational age at the time of delivery. As compared to women with GDM, women who had hypoglycaemia during OGTT had similar gestational age at the time of delivery [MD 0.43 weeks; 95%CI -.35 – 1.21; P = .281; I2 = 97%; Figure 4f].

DISCUSSION

Though hypoglycaemia is not uncommon during OGTT in pregnancy for screening GDM, it is most often ignored. This is the first SRM to highlight that hypoglycaemia detected during OGTT in pregnancy is clinically relevant. Compared to women with normoglycaemia, hypoglycaemia during OGTT in pregnancy was associated with significantly lower birthweight, increased risks of SGA, increased NICU admission, and increased risk of 5-min Apgar score <8 at birth, suggestive of an adverse impact on foetal outcomes. Decreased risk of macrosomia is on expected lines. The reduced need for CS in women with hypoglycaemia during OGTT can be explained by the smaller babies, which are more easily delivered vaginally.

Our SRM also noted that lower pre-pregnancy maternal body weight, a trend towards increased weight gain during pregnancy are predictors of hypoglycaemia. Maternal pre-pregnancy weight is known to be closely linked with the birth weight of the neonate.[27] Women who are overweight or obese are more likely to have infants with higher birth weight, whereas underweight mothers are more likely to have SGA infants.[27] The profile of women having low pregnancy weight with increased weight gain during pregnancy may represent the thrifty phenotype. Our analysis showed that women with hypoglycaemia during OGTT in pregnancy were more likely to have gestational hypertension. Gestational hypertension is well known to be associated with adverse feto-maternal outcomes.[28] The higher degree of insulin resistance in these women enhances the risk of reactive hypoglycaemia and is associated with adverse feto-maternal outcomes. The excessive weight gain during pregnancy is believed to result in foetal programming that predisposes offspring to obesity and metabolic syndrome later in life.[29]

Our analysis noted similar rates of SGA, LGA, 5AS, maternal age, CS, and gestational age at time of delivery in women with hypoglycaemia during OGTT as compared to GDM. This indicates that the hypoglycaemia during OGTT could be an additional marker that needs to be addressed. The novelty of this SRM is that it highlights, for the first time hypoglycaemia during OGTT can be a marker of adverse feto-maternal outcomes. Hypoglycaemia detected during OGTT in pregnancy should not be ignored and should be given importance similar to GDM. Studies are warranted looking at therapeutic diet and lifestyle changes in women with hypoglycaemia during OGTT in pregnancy to improve the feto-maternal outcomes. The strengths of this SRM include analysis of data derived from multiple studies conducted across diverse geographic regions and healthcare settings. However, limitations include the presence of data heterogeneity, and not all studies reported on all the outcomes studied. Also lack of sufficient RCTs on this topic is another drawback.

CONCLUSION

To conclude, hypoglycaemia during OGTT is associated with lower birthweight, increased SGA, higher NICU admission, and higher probability of 5 min Apgar score <8. Lower maternal pre-pregnancy weight is a predictor of hypoglycaemia during OGTT. The adverse feto-maternal outcome rates are similar to GDM, and further studies to define strategies to improve outcomes in women who developed hypoglycaemia during OGTT are necessary.

Author contributions

The study was conceptualized by DD. Literature search was done by DD, SB and RJ. Data entry was done by ABMKH, RJ and AJ. Analysis was done by DD, MK, ABMKH and AJ. All authors contributed equally to manuscript preparation.

The systematic review and metanalysis followed a preestablished protocol registered on PROSPERO (CRD42025644556) and adhered to PRISMA guidelines.

Conflicts of interest

There are no conflicts of interest.

Use of artificial intelligence

Artificial intelligence was not used in any form in the planning as well as the execution of the study and manuscript preparation.

Data availability

The raw data is available with the authors and can be provided on request.

Acknowledgements

None.

Funding Statement

Nil.

REFERENCES

  • 1.Sweeting A, Hannah W, Backman H, Catalano P, Feghali M, Herman WH, et al. Epidemiology and management of gestational diabetes. Lancet Lond Engl. 2024;404:175–92. doi: 10.1016/S0140-6736(24)00825-0. [DOI] [PubMed] [Google Scholar]
  • 2.Wang H, Li N, Chivese T, Werfalli M, Sun H, Yuen L, et al. IDF diabetes atlas: Estimation of global and regional gestational diabetes mellitus prevalence for 2021 by International Association of Diabetes in pregnancy study group's criteria. Diabetes Res Clin Pract. 2022;183:109050. doi: 10.1016/j.diabres.2021.109050. [DOI] [PubMed] [Google Scholar]
  • 3.Bhattacharya S, Nagendra L, Dutta D, Kamrul-Hasan ABM. Treatment versus observation in early gestational diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials. J Clin Endocrinol Metab. 2024:dgae878. doi: 10.1210/clinem/dgae878. [DOI] [PubMed] [Google Scholar]
  • 4.Bhattacharya S, Nagendra L, Dutta D, Mondal S, Bhat S, Raj JM, et al. First-trimester fasting plasma glucose as a predictor of subsequent gestational diabetes mellitus and adverse fetomaternal outcomes: A systematic review and meta-analysis. Diabetes Metab Syndr. 2024;18:103051. doi: 10.1016/j.dsx.2024.103051. [DOI] [PubMed] [Google Scholar]
  • 5.Delibas IB, Tanriverdi S, Cakmak B. Does reactive hypoglycemia during the 100 g oral glucose tolerance test adversely affect perinatal outcomes? Ginekol Pol. 2018;89:25–9. doi: 10.5603/GP.a2018.0005. [DOI] [PubMed] [Google Scholar]
  • 6.Raviv S, Wilkof-Segev R, Maor-Sagie E, Naeh A, Yoeli Y, Hallak M, et al. Hypoglycemia during the oral glucose tolerance test in pregnancy-maternal characteristics and neonatal outcomes. Int J Gynaecol Obstet. 2022;158:585–91. doi: 10.1002/ijgo.14037. [DOI] [PubMed] [Google Scholar]
  • 7.Haggiag N, Rotman M, Hallak M, Toledano Y, Gabbay-Benziv R, Maor-Sagie E. Hypoglycemia in oral glucose tolerance test during pregnancy and risk for type 2 diabetes-A five-year cohort study. J Clin Med. 2024;13:3806. doi: 10.3390/jcm13133806. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8.Rehman S, Kazi S, Shah H, Wallis N, Mahindra P, Al Wattar BH, et al. Reactive hypoglycaemia at glucose tolerance test-another presentation of gestational diabetes: A multicentre retrospective study. BJOG. 2025 Feb 25; doi: 10.1111/1471-0528.18105. doi:10.1111/1471-0528.18105. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 9.Quansah DY, De Giorgi S, Le Dizes O, Camponovo C, Benhalima K, Cosson E, et al. Reactive hypoglycaemia during the OGTT after gestational diabetes mellitus: Metabolic implications and evolution. Diabet Med J Br Diabet Assoc. 2022;39:e14920. doi: 10.1111/dme.14920. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10.Moher D, Liberati A, Tetzlaff J, Altman DG PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses:the PRISMA statement. PLoS Med. 2009;6:e1000097. doi: 10.1371/journal.pmed.1000097. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 11.Stentebjerg LL, Madsen LR, Støving RK, Juhl CB, Vinter CA, Andersen LLT, et al. Hypoglycemia in pregnancies following gastric bypass-A systematic review and meta-analysis. Obes Surg. 2022;32:2047–55. doi: 10.1007/s11695-022-06021-z. [DOI] [PubMed] [Google Scholar]
  • 12.Macrosomia: ACOG Practice Bulletin. Number 216. Obstet Gynecol. 2020;135:e18–35. doi: 10.1097/AOG.0000000000003606. [DOI] [PubMed] [Google Scholar]
  • 13.Ye J, Zhang L, Chen Y, Fang F, Luo Z, Zhang J. Searching for the definition of macrosomia through an outcome-based approach. PLoS One. 2014;9:e100192. doi: 10.1371/journal.pone.0100192. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 14.Higgins JPT, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta-analyses. BMJ. 2003;327:557–60. doi: 10.1136/bmj.327.7414.557. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Roth JV. Prediction interval analysis is underutilized and can be more helpful than just confidence interval analysis. J Clin Monit Comput. 2009;23:181–3. doi: 10.1007/s10877-009-9165-0. [DOI] [PubMed] [Google Scholar]
  • 16.Sterne JAC, Savović J, Page MJ, Elbers RG, Blencowe NS, Boutron I, et al. RoB 2: A revised tool for assessing risk of bias in randomised trials. BMJ. 2019;366:l4898. doi: 10.1136/bmj.l4898. [DOI] [PubMed] [Google Scholar]
  • 17.Stang A. Critical evaluation of the Newcastle-Ottawa scale for the assessment of the quality of nonrandomized studies in meta-analyses. Eur J Epidemiol. 2010;25:603–5. doi: 10.1007/s10654-010-9491-z. [DOI] [PubMed] [Google Scholar]
  • 18.Bayraktar B, Balıkoğlu M, Kanmaz AG. Pregnancy outcomes of women with hypoglycemia in the oral glucose tolerance test. J Gynecol Obstet Hum Reprod. 2020;49:101703. doi: 10.1016/j.jogoh.2020.101703. [DOI] [PubMed] [Google Scholar]
  • 19.Blunt C, Mathew S, Mung SM, Krishnamurthy R, Jude EB. Hypoglycaemia following the 2-hour 75g OGTT in pregnancy-Investigating maternal and foetal outcomes. Diabetes Metab Syndr. 2024;18:102977. doi: 10.1016/j.dsx.2024.102977. [DOI] [PubMed] [Google Scholar]
  • 20.Weissman A, Solt I, Zloczower M, Jakobi P. Hypoglycemia during the 100-g oral glucose tolerance test: Incidence and perinatal significance. Obstet Gynecol. 2005;105:1424–8. doi: 10.1097/01.AOG.0000159577.28448.f9. [DOI] [PubMed] [Google Scholar]
  • 21.Pugh SK, Doherty DA, Magann EF, Chauhan SP, Hill JB, Morrison JC. Does hypoglycemia following a glucose challenge test identify a high risk pregnancy? Reprod Health. 2009;6:10. doi: 10.1186/1742-4755-6-10. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 22.Topçu HO, İskender CT, Çelen Ş, Oskovi A, Uygur D, Erkaya S. Maternal hypoglycemia on 50 g glucose challenge test:outcomes are influenced by fetal gender. J Perinat Med. 2016;44:369–76. doi: 10.1515/jpm-2015-0060. [DOI] [PubMed] [Google Scholar]
  • 23.Feinberg JH, Magann EF, Morrison JC, Holman JR, Polizzotto MJ. Does maternal hypoglycemia during screening glucose assessment identify a pregnancy at-risk for adverse perinatal outcome? J Perinatol Off J Calif Perinat Assoc. 2005;25:509–13. doi: 10.1038/sj.jp.7211336. [DOI] [PubMed] [Google Scholar]
  • 24.Calfee EF, Rust OA, Bofill JA, Ross EL, Morrison JC. Maternal hypoglycemia: Is it associated with adverse perinatal outcome? J Perinatol. 1999;19:379–82. doi: 10.1038/sj.jp.7200048. [DOI] [PubMed] [Google Scholar]
  • 25.Budak MŞ, Araç E. Maternal hypoglycaemia on the 50 g oral glucose challenge test-evaluation of obstetric and neonatal outcomes. Ginekol Pol. 2018;89:370–4. doi: 10.5603/GP.a2018.0063. [DOI] [PubMed] [Google Scholar]
  • 26.Yuen L, Bontempo S, Wong VW, Russell H. Hypoglycaemia on an oral glucose tolerance test in pregnancy-Is it clinically significant? Diabetes Res Clin Pract. 2019;147:111–7. doi: 10.1016/j.diabres.2018.11.018. [DOI] [PubMed] [Google Scholar]
  • 27.Vats H, Saxena R, Sachdeva MP, Walia GK, Gupta V. Impact of maternal pre-pregnancy body mass index on maternal, fetal and neonatal adverse outcomes in the worldwide populations: A systematic review and meta-analysis. Obes Res Clin Pract. 2021;15:536–45. doi: 10.1016/j.orcp.2021.10.005. [DOI] [PubMed] [Google Scholar]
  • 28.Nzelu D, Dumitrascu-Biris D, Hunt KF, Cordina M, Kametas NA. Pregnancy outcomes in women with previous gestational hypertension: A cohort study to guide counselling and management. Pregnancy Hypertens. 2018;12:194–200. doi: 10.1016/j.preghy.2017.10.011. [DOI] [PubMed] [Google Scholar]
  • 29.Arentson-Lantz EJ, Buhman KK, Ajuwon K, Donkin SS. Excess pregnancy weight gain leads to early indications of metabolic syndrome in a swine model of fetal programming. Nutr Res N Y N. 2014;34:241–9. doi: 10.1016/j.nutres.2014.01.001. [DOI] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

The raw data is available with the authors and can be provided on request.

Articles from Indian Journal of Endocrinology and Metabolism are provided here courtesy of Wolters Kluwer -- Medknow Publications

RESOURCES