Abstract
Obesity in women, a global issue, is being widely managed with bariatric surgery worldwide. According to recommended guidelines, pregnancy should be avoided for 12 to 24 months following surgery due to various risks. We assessed if surgery-to-conception time has a relation with pregnancy outcomes taking into account gestational weight gain. A cohort study between 2015 and 2019 followed-up pregnancies after various types of bariatric surgeries performed (e.g. Roux-en-Y gastric bypass, sleeve gastrectomy, gastric banding, gastric bypass with Roux-en-Y gastroenterostomy) in Tawam Hospital, Al Ain, United Arab Emirates. There were 5 surgery-to-conception groups: <6 months, 6 to 12 months, 13 to 18 months, 19 to 24 months, and >24 months. There were 3 gestational weight gain groups: inadequate, adequate, or excessive (based on the National Academy of Medicine classification). Maternal and neonatal outcomes were compared using analysis of variance and chi-square tests. There were 158 pregnancies. Booking maternal body mass index and weight were higher among mothers who conceived <6 months following surgery (P < .001). Gestational weight gain was not related to the type of bariatric surgery (P = .24), but it was far more often inadequate in mothers who conceived <12 months following surgery (P = .002). Maternal (including pregnancy-induced hypertension and gestational diabetes mellitus) and neonatal outcomes were not statistically significantly associated with surgery-to-conception duration. However, birth weight was lower when gestational weight gain was inadequate (P = .03). There is a negative relationship between shorter bariatric surgery-to-conception interval and gestational weight gain, a feature related to neonatal birth weight. Conception should be delayed to improve pregnancy outcomes following bariatric surgery.
Keywords: gestational weight gain, maternal and neonatal outcomes, Roux-en-Y gastric bypass, sleeve gastrectomy
1. Introduction
Obesity is a global epidemic due to its high prevalence throughout the world. It has emerged as one of the most significant health challenges, including in the middle east.[1] Over the past 2 decades, its frequency has more than doubled on a global scale.[2] Bariatric surgery is a frequently used treatment for morbid obesity.[3] Its growing popularity might be due to poor success with weight loss by diet alone. The efficacy of bariatric surgery in achieving significant weight loss and improving obesity-related comorbidities has been well documented.[4,5] Obese women of reproductive age undergoing bariatric surgery need to be aware of the issues relevant to a future pregnancy.
The optimal timing of pregnancy following bariatric surgery requires uniformity in recommendations among guidelines. Women are generally advised not to conceive for 12 to 18 or 24 months following bariatric surgery.[6,7] Fertility is improved after bariatric surgery through the restoration of ovulation so the timing of conception after bariatric surgery becomes a key clinical issue.[8] Pregnancies following bariatric surgical procedures should be regarded as high-risk and closely monitored by a multidisciplinary team due to the increased incidence of intrauterine growth restriction, small for gestational age, congenital abnormalities, and preterm birth.[9] These risks might be more obvious in pregnancies that occur within the first 12 months following bariatric surgery because malnutrition risk is thought to be highest during this time due to reduced caloric intake and rapid weight loss.[10] As a result, the growing fetus may receive less nutrition. An important factor influencing pregnancy outcomes, particularly neonatal birthweight, is gestational weight gain.[11] However, the risks of pregnancy-induced hypertension and gestational diabetes mellitus are likely to be reduced.[12]
Previous studies have looked at the outcomes of pregnancies following bariatric procedures. They have examined the pregnancy trajectory and neonatal outcomes in women who conceived at various intervals following bariatric surgery, but the results were frequently constrained by study design and sample size-related issues.[6,7,13] Importantly, the effects of gestational weight gain have not been fully examined. Given this background, the objective of our study was to assess pregnancy outcomes for both mother and neonate based on the time from surgery to conception and compliance with the guidelines for gestational weight gain.
2. Methods
This study’s protocol was approved by the Ethics Committee for Research in Tawam Hospital, Al Ain, United Arab Emirates (UAE) (Ref. No.: AA/AJ/819, December 16, 2021). It was a cohort study. The data were extracted from electronic medical records of female patients who underwent bariatric surgery and sought obstetric care at Tawam Hospital between 2015 and 2019. The types of bariatric surgery included Roux-en-Y gastric bypass, sleeve gastrectomy, gastric banding, and gastric bypass with Roux-en-Y gastroenterostomy. Exclusion criteria included multiple births, spontaneous or elective abortions, preexisting diabetes mellitus, and insufficient information about the pregnancy’s course.
The time from surgery to conception and adherence to the National Academy of Medicine’s gestational weight gain recommendations were used to categorize all pregnancies. The time from surgery to conception was defined as the period in months between the date of surgery and the first day of the last menstrual period. Based on the surgery-to-conception time interval, patients were categorized into 5 groups: <6 months, 6 to 12 months, 13 to 18 months, 19 to 24 months, and >24 months. Booking body mass index (BMI) was calculated and documented. Gestational weight gain was calculated as the difference between predelivery pregnancy weight and booking (8–12 weeks) pregnancy weight. The National Academy of Medicine’s gestational weight gain recommendations were then used to categorize weight gain as inadequate, adequate, or excessive.[14]
In addition to surgery-to-conception interval and gestational weight gain, the primary outcome variables included gestational age at delivery, preterm birth, birth weight, and intrauterine growth restriction. Preterm birth was defined as occurring before 37 weeks of pregnancy. Pregnancy-related complications such as preeclampsia (hypertension and proteinuria), gestational diabetes mellitus (new-onset, diagnosed by glucose monitoring), pregnancy-induced hypertension (new-onset, above 140/90 mm Hg on 2 occasions), and postpartum hemorrhage (postpartum bleeding of >1000 mL) were also investigated.
Maternal and neonatal outcomes were compared using analysis of variance and chi-square tests. Statistical significance threshold was P < .05.
3. Results
A total of 158 pregnant women who previously underwent bariatric surgery were included. The most commonly performed bariatric procedure was sleeve gastrectomy (81.5%), followed by Roux-en-Y gastric bypass (10.2%), gastric banding (7.01%), and gastric bypass with Roux-en-Y gastroenterostomy (1.2%). Bariatric surgery-to-conception interval was < 6 months in 13.8%, 6 to 12 months in 29.7%, 13 to 18 months in 18.4%, 19 to 24 months in 8.9%, and > 24 months in 29.1%. Gestational weight gain was adequate in 26.6% of the pregnancies, inadequate in 58.2%, and excessive in 15.2%. The demographic characteristics of the sample are shown in Tables 1 and 2. Maternal age was not different according to the surgery-to-conception interval or maternal weight gain categories. Booking BMI and weight were higher among mothers who conceived <6 months following surgery (P < .001).
Table 1.
Prepregnancy characteristics according to time from surgery to conception.
| Time period | ||||||
|---|---|---|---|---|---|---|
| Characteristics | <6 months (n = 22) | 7–12 months (n = 47) | 13–18 months (n = 29) | 19–24 months (n = 14) | >24 months (n = 46) | P value |
| Age | 32 ± 6.03 | 31.74 ± 5.86* | 33.48 ± 5.51 | 29.28 ± 5.19 | 31.76 ± 6.09 | .639 |
| Booking BMI (kg/m2) | 33.81 ± 6.53 | 29.71 ± 5.28 | 29.01 ± 5.36 | 25.07 ± 4.49 | 28.63 ± 5.42 | .001 |
| Booking weight (kg) | 86.91 ± 14.96 | 76.36 ± 15.01 | 75.57 ± 15.59 | 65.57 ± 16.50 | 72.11 ± 13.19 | .001 |
| Type of surgery† | .031‡ | |||||
| Sleeve gastrectomy | 15 (71.4) | 36 (76.6) | 28 (96.5) | 11 (78.6) | 38 (82.6) | |
| Roux-en-Y gastric bypass | 3 (14.3) | 7 (14.9) | 1 (3.5) | 2 (14.3) | 3 (6.5) | |
| Gastric banding | 1 (4.8) | 4 (8.5) | 0 | 1 (7.1) | 5 (10.9) | |
| Roux-en-Y gastric bypass and gastroenterostomy | 2 (9.5) | 0 | 0 | 0 | 0 |
Data presented as mean ± SD or frequencies (percentages).
BMI = body mass index.
1 patient’s data missing.
†1 patient’s data missing in group 1.
‡Calculated by chi-square test.
Table 2.
Prepregnancy characteristics according to adherence to the National Academy of Medicine recommendations for gestational weight gain.
| Characteristics | Inadequate (n = 92) | Adequate (n = 42) | Excessive (n = 24) | P value |
|---|---|---|---|---|
| Age | 32.01 ± 5.73 | 31.31 ± 6.59 | 32.08 ± 5.07 | .76 |
| Booking BMI (kg/m2) | 30.1 ± 5.71 | 28.03 ± 5.42 | 29.26 ± 6.59 | .16 |
| Booking weight (kg) | 76.51 ± 14.34 | 72.49 ± 16.55 | 76.81 ± 18.15 | .348 |
| Type of surgery† | .24‡ | |||
| Sleeve gastrectomy | 73 (80.2) | 36 (85.7) | 18 (75) | |
| Roux-en-Y gastric bypass | 13 (14.3) | 2 (4.8) | 2 (8.3) | |
| Gastric banding | 3 (3.3) | 4 (9.5) | 4 (16.7) | |
| Roux-en-Y gastric bypass and gastroenterostomy | 2 (2.2) | 0 | 0 |
Data presented as mean ± SD or frequencies (percentages).
BMI = body mass index.
*1 patient’s data missing.
†1 patient’s data missing in group 1.
‡Calculated by chi-square test.
We tabulated maternal and neonatal outcomes according to surgery-to-conception interval in Tables 3 and 4. Gestational weight gain was not related to the type of bariatric surgery (P = .24), but it was far more often inadequate in mothers who conceived <12 months following surgery (P = .002). Maternal complications showed gestational diabetes mellitus to be the most prevalent (13.3%). Only 1 mother suffered from new-onset hypertension during pregnancy and 2 experienced postpartum hemorrhage. There was a single case of intrauterine fetal death. Maternal and neonatal outcomes were not statistically significantly associated with surgery-to-conception interval. Maternal outcomes were not statistically significantly associated with gestational weight gain groups, but birth weight was lower when gestational weight gain was inadequate (P = .03).
Table 3.
Pregnancy outcomes according to time from surgery to conception.
| Time period | ||||||
|---|---|---|---|---|---|---|
| Characteristics | <6 months (n = 22) | 7–12 months (n = 47) | 13–18 months (n = 29) | 19–24 months (n = 14) | >24 months (n = 46) | P value |
| Maternal outcomes | ||||||
| Gestational age (wk) | 38.27 ± 1.07 | 38.13 ± 1.92 | 37.55 ± 1.48 | 37.93 ± 1.14 | 37.82 ± 2.15 | .54 |
| Gestational weight gain (kg) | −9.29 ± 14.24 | 3.14 ± 7.23 | 6.44 ± 9.44 | 9.73 ± 6.15 | 8.44 ± 6.85 | .001 |
| Delivery weight (kg) | 77.61 ± 8.21 | 79.49 ± 15.91 | 82.01 ± 16.54 | 75.30 ± 16.79 | 80.55 ± 14.14 | .81 |
| Preterm birth (<37 wk) | 2 (9.1) | 9 (19.1) | 8 (27.6) | 1 (7.1) | 10 (21.7) | .42 |
| Weight gain according to the National Academy of Medicine recommendations | .002** | |||||
| Inadequate | 20 (90.9) | 32 (68.1) | 13 (44.8) | 6 (42.9) | 21 (45.6) | |
| Adequate | 1 (4.5) | 12 (25.5) | 10 (34.5) | 3 (21.4) | 16 (34.8) | |
| Excessive | 1 (4.5) | 3 ((6.4) | 6 (20.7) | 5 (35.7) | 9 (19.6) | |
| Maternal complications | ||||||
| Gestational diabetes | 5 (22.7) | 7 (14.9) | 2 (6.9) | 2 (14.3) | 5 (10.9) | .52 |
| Pregnancy-induced hypertension | 0 | 0 | 0 | 0 | 1 (2.2) | .65 |
| Postpartum hemorrhage | 1 (4.5) | 0 | 1 (3.4) | 0 | 1 (2.2) | .67 |
| Neonatal outcomes | ||||||
| Intrauterine growth restriction (based on ultrasound estimated fetal weight) | 4 (18.2) | 9 (19.1) | 5 (17.2) | 3 (21.4) | 11 (23.9) | .95 |
| Birth weight (kg) | 2.91 ± 0.47 | 2.74 ± 0.66 | 2.71 ± 0.41* | 2.86 ± 0.37 | 2.77 ± 0.49 | .36 |
| Admission to neonatal intensive care unit | 2 (9.1) | 9 (19.1) | 6 (20.7) | 3 (21.4) | 8 (17.4) | .75 |
Data are presented as mean ± SD or frequencies (percentages).
Intrauterine fetal demise (n = 1).
Calculated by chi-square test.
Table 4.
Pregnancy and neonatal outcomes according to adherence to the National Academy of Medicine recommendations for gestational weight gain.
| Characteristics | Inadequate (n = 92) | Adequate (n = 42) | Excessive (n = 24) | P value |
|---|---|---|---|---|
| Pregnancy outcomes | ||||
| Gestational age (wk) | 37.4 ± 4.31 | 37.97 ± 1.71 | 36.21 ± 1.84 | .66 |
| Gestational weight gain (kg) | −1.49 ± 9.67 | 9.64 ± 3.23 | 16.09 ± 5.40 | .001 |
| Delivery weight | 75.02 ± 10.5 | 82.14 + 16.44 | 92.91 ± 16.63 | .001 |
| Preterm birth | 19 (20.6) | 7 (16.7) | 4 (16.7) | .82* |
| Maternal complications | ||||
| Gestational diabetes | 15 (16.3) | 4 (9.5) | 2 (3.4) | .41* |
| Pregnancy-induced hypertension | 2 (2.2) | 0 | 0 | .69* |
| Postpartum hemorrhage | 1 (1.1) | 1 (2.4) | 1 (4.2) | .59* |
| Neonatal outcomes | ||||
| Intrauterine growth restriction (based on ultrasound estimated fetal weight) | 19 (20.6) | 12 (28.6) | 1 (4.2) | .059* |
| Birth weight (kg) | 2.66 ± 0.63 | 2.87 ± 0.44 | 2.82 + 0.73 | .03 |
| Admission to neonatal intensive care unit | 16 (17.4) | 9 (21.4) | 3 (12.5) | .66* |
Data presented as mean ± SD or frequencies (percentages).
Calculated by chi-square test.
4. Discussion
We found that booking BMI and weight were higher among mothers who conceived early following bariatric surgery. Gestational weight gain was not related to the type of bariatric surgery, but it was far more often inadequate in mothers who conceived early following surgery. Maternal (including pregnancy-induced hypertension and gestational diabetes mellitus) and neonatal outcomes were not statistically significantly associated with surgery-to-conception interval. However, birth weight was lower when gestational weight gain was inadequate. Thus, early conception following bariatric surgery was associated with undesirable outcomes.
To our knowledge, limited data are available regarding the optimal timing of pregnancy following bariatric surgery and related outcomes in the UAE population. This study adds important information to available data on pregnancy timing following bariatric surgery in a UAE sample that will help clinicians as well as patients. STROBE checklist was followed to report the findings of this study transparently. Our study had some limitations, including its small sample size which may be an obstacle in generalizing the results of our study. It is recommended that future researchers should include a larger sample size. Further, we were not able to perform the analysis for large and small gestational age neonates (>90th percentile and <10th percentile respectively) due to the unavailability of data. The outcomes of our study might have been influenced by the different types of bariatric surgeries that were performed. Although the design was retrospective, there were no issues related to recall bias as the variables studied were objective in nature. This lends credibility to our findings.
Comparison of our findings with previous studies leads to interesting observations. A 2019 cohort study in UAE reported >70% had abnormal, either inadequate or excessive, gestational weight gain. The risk of excessive weight gain was associated with higher prepregnancy BMI.[15] Nearly 75% of women had abnormal gestational weight gain in our study and booking BMI was higher in women who had shorter surgery-to-conception interval. A multicenter retrospective study of pregnant women following bariatric surgeries in the Netherlands concluded that the pregnancy should be avoided for at least 12 months following bariatric surgery as early pregnancy carries a risk of lower gestational weight gain.[6] Our findings also support this claim. In a retrospective cohort study conducted in the USA, it was reported that women who conceived early (<12 months) following bariatric surgery had significantly lower gestational weight gain compared to women who conceived late (>12 months).[7] Our study also showed inadequate gestational weight gain in women who conceived in <12 months following bariatric surgery. A previous bicentric retrospective study reported that adequate gestational weight gain following bariatric surgery resulted in better obstetrical outcomes in conceiving mothers.[11] In our study, inadequate gestational weight gain was observed in mothers who conceived earlier than 12 months following bariatric surgery. Though maternal outcomes were not statistically significant, low birth weight was prevalent in women with inadequate gestational weight gain. Contrary to this, a recent 2023 study’s results showed that gestational weight gain following bariatric surgery was not associated with birth weight.[16] This could be because the majority of the women conceived many years after their bariatric surgery, following the optimal timing of pregnancy following bariatric surgery.
Our findings provide recommendations regarding the timing of pregnancy following bariatric surgery. The conception should be delayed to improve pregnancy outcomes following bariatric surgery. Contraception should be effectively deployed as fertility is regained following surgery. Maternal weight gain guidance should be closely adhered to in practice. Future research should focus on the effect of inadequate gestational weight gain and maternal undernutrition on the duration of pregnancy and fetal growth, aiming to reduce the increased prevalence of small for gestational-age neonates after maternal bariatric surgery. These should deploy prospective designs with large sample sizes for more precise, valid, and generalizable findings.
5. Conclusion
Our study confirms that postponement of pregnancy for 12 to 24 months following bariatric surgery is recommendable. Conception should be delayed to improve pregnancy outcomes following bariatric surgery and nutritional aspects of pregnancy should be observed to avoid inadequate or excessive maternal gestational weight gain.
Author contributions
Conceptualization: Sadia Solaiman, Omaema Omar Al-Baghdadi, Thin Thin Hla, Shabana Abdulmajid Kapadia.
Data curation: Sadia Solaiman.
Formal analysis: Hassan M. Elbiss.
Methodology: Sadia Solaiman, Hassan M. Elbiss.
Supervision: Hassan M. Elbiss.
Writing – original draft: Sadia Solaiman, Omaema Omar Al-Baghdadi, Shabana Abdulmajid Kapadia.
Writing – review & editing: Thin Thin Hla, Hassan M. Elbiss.
Abbreviations:
- BMI
- body mass index
- UAE
- United Arab Emirates
The authors have no funding to disclose.
The authors have no conflicts of interest to disclose.
The datasets generated during and/or analyzed during the current study are not publicly available, but are available from the corresponding author on reasonable request.
How to cite this article: Solaiman S, Al-Baghdadi OO, Thin Hla T, Abdulmajid Kapadia S, Elbiss HM. Maternal and perinatal outcomes in women conceiving after bariatric surgery: A cohort study. Medicine 2023;102:24(e33913).
Contributor Information
Sadia Solaiman, Email: sadia.solaiman@gmail.com.
Omaema Omar Al-Baghdadi, Email: oalbaghdadi@yahoo.co.uk.
Thin Thin Hla, Email: thla@seha.ae.
Shabana Abdulmajid Kapadia, Email: skapadia@seha.ae.
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