Outcomes of pregnancy after bariatric surgery: results of a French matched-cohort study

The Relationship Between Obesity, Bariatric Surgery, and Infertility: A Systematic Review

BACKGROUND

Obesity is a complicated, chronic condition that has a major impact on reproductive health, leading to infertility, anovulation, and poor pregnancy outcomes. It alters the hypothalamic-pituitary-ovarian (HPO) axis, promotes insulin resistance, and causes persistent low-grade inflammation, all of which result in hormonal abnormalities that compromise normal ovarian function. Because standard weight loss procedures frequently fail to provide significant and long-term reproductive benefits, bariatric surgery is becoming increasingly popular as a therapeutic option for obese women trying to conceive. However, continuous research is being conducted to determine the degree of its advantages and potential hazards to fertility and pregnancy outcomes.

METHODS

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards and entered into the PROSPERO database. Comprehensive searches in the PubMed, Scopus, and Web of Science databases turned up relevant studies. Studies that examined the effects of bariatric surgery on female fertility, ovulatory function, pregnancy rates, and neonatal outcomes were considered. Methodological quality and risk of bias were evaluated using the Newcastle-Ottawa Scale (NOS) for observational studies and the Cochrane Risk of Bias Tool for randomized controlled trials.

RESULTS

This review comprised 34 studies. More than 75% of the studies analyzed showed improvements in ovulatory function, monthly regularity, or spontaneous pregnancy after bariatric surgery. Post-surgical pregnancies are related to a lower incidence of gestational diabetes, hypertension, and macrosomia. However, several studies raised concerns about nutritional inadequacies and the possibility of small-for-gestational-age newborns, particularly following Roux-en-Y gastric bypass. Studies suggest delaying conception for 12 to 18 months after surgery to reduce nutritional hazards and improve pregnancy outcomes. Variability in study design, follow-up duration, and surgical methods reduces the generalizability of findings, emphasizing the importance of uniform research protocols.

CONCLUSIONS

Bariatric surgery is a highly effective treatment for increasing fertility and pregnancy outcomes in obese women, particularly those with PCOS. However, rigorous preconception planning, postoperative nutritional monitoring, and multidisciplinary follow-up are required to reduce the related hazards. Future research should concentrate on long-term reproductive outcomes, standardizing fertility assessment criteria, and improving clinical guidelines for managing post-bariatric pregnancies. These findings support the incorporation of bariatric surgery into fertility treatment regimens for obese women, and they may shape future revisions to clinical guidelines on reproductive care following weight loss surgery.

Pregnancy and offspring outcomes after prepregnancy bariatric surgery

BACKGROUND

Bariatric surgery is internationally performed as a treatment option in obesity to achieve significant and sustained weight loss. There is an increasing number of women having pregnancies after bariatric surgery with mixed maternal and fetal outcomes, with a limited number of large, matched studies.

OBJECTIVE

This study aimed to describe the type of prepregnancy bariatric surgery, analyze maternal, pregnancy, and offspring outcomes relative to matched women, and assess the impact of prepregnancy bariatric surgery on fetal growth, particularly the proportions of small for gestational age and large for gestational age infants.

STUDY DESIGN

A cross-sectional, matched study was performed using a statewide hospital and perinatal data register. A total of 2018 births of 1677 women with prepregnancy bariatric surgery were registered between 2013 and 2018. Of those, 1282 were included and analyzed, matched in a 1:10 ratio for age, parity, smoking status, and body mass index to women without bariatric surgery. The first singleton pregnancy following bariatric surgery for each woman was used for analysis. Pregnancy and neonatal outcomes based on International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification, and neonatal birth records were analyzed. Multivariable logistic regression was used to estimate the association between small for gestational age and large for gestational age infants and prepregnancy bariatric surgery.

RESULTS

Of the 1282 women, 93% had undergone laparoscopic sleeve gastrectomy. Among women with prepregnancy bariatric surgery compared with matched women, offspring had lower absolute birthweight (3223±605 vs 3418±595 g; P<.001), and a lower rate of large for gestational age infants (8.6% vs 14.1%; P<.001) and a higher rate of small for gestational age infants (10.7% vs 7.3%; P<.001) were found. Offspring of mothers with prepregnancy bariatric surgery were more likely to be born preterm (10.5% vs 7.8%; P=.007). Fewer women with previous bariatric surgery were diagnosed with gestational diabetes mellitus (15% vs 20%; P<.001) or pregnancy-induced hypertension (3.7% vs 5.4%; P=.01). In the adjusted model, prepregnancy bariatric surgery was associated with lower risk of large for gestational age (odds ratio, 0.54; 95% confidence interval, 0.44-0.66) and higher risk of small for gestational age infants (odds ratio, 1.78, 95% confidence interval, 1.46-2.17).

CONCLUSION

These data suggest that prepregnancy bariatric surgery was associated with a reduction in several obesity-related pregnancy complications at the expense of more preterm births and small for gestational age offspring.

The approach to a pregnancy after bariatric surgery

With a rising worldwide incidence of obesity, particularly in the young, bariatric surgery offers an effective method of meaningful and sustained weight loss. At present, most bariatric procedures are carried out in women and increasingly in younger age groups. In line with the fertility benefits associated with weight loss, pregnancy after bariatric surgery is now a very common scenario. Although there is limited evidence to support optimal care in this group, most women appear to have good pregnancy outcomes, with reduced rates of pre-eclampsia and gestational diabetes (GDM). However, rates of stillbirth and small-for-gestational-age (SGA) babies are increased, suggesting that screening and supplementation of micronutrients is likely to be very important in this cohort. The risks and benefits that bariatric surgery may pose to pregnancy outcomes, both maternal and fetal, are largely dependent upon the degree of weight loss, weight stability upon entering pregnancy, surgical complications and the time interval between bariatric surgery and pregnancy. Ideally, preconception care would be more widely available, helping to assess and address micronutrient deficiencies and support preparation for pregnancy.

Gestational Diabetes Risk and Low Birth Weight After Metabolic Bariatric Surgery: a Complex Interplay to be Balanced

INTRODUCTION

Metabolic bariatric surgery (MBS) is known to improve the obstetric outcomes of women with obesity and to prevent gestational diabetes (GD). To what extent does MBS decreases GD, without incurring at additional risks is a matter of concern.

METHODS

A retrospective case-control study to compare the pregnancy outcomes of women previously submitted to MBS to those of age and preconception body mass index (PC BMI) matched non-operated controls.

RESULTS

Pregnancies of women after MBS (n = 79) and matched controls (n = 79) were included. GD was significantly less frequent after MBS (7.6% vs. 19%; p = 0.03). Fasting blood glucose (76.90 ± 0.77 vs 80.37 ± 1.15 mg/dl, p < 0.05; 70.08 ± 1.34 vs. 76.35 ± 0.95 mg/dl; p < 0.05, first and second trimesters respectively) and birth weight (2953.67 ± 489.51 g vs. 3229.11 ± 476.21 g; p < 0.01) were significantly lower after MBS when compared to controls. The occurrence of small-for-gestational-age (SGA) was more frequent after MBS (22.8% vs. 6.3%; p < 0.01), but no longer significant after controlling for smoking habits (15.5% vs. 6%, p = 0.14). There were no significant differences in gestational weight gain, prematurity rate nor mode of delivery between groups.

CONCLUSION

MBS was associated with a lower prevalence of GD than observed in non-operated women with the same age and BMI. After controlling for smoking, this occurred at the expense of a lower birth weight. Our data reinforces the hypothesis that MBS has body weight independent effects on glucose kinetics during pregnancy with distinctive impacts for mother and offspring, which need to be balanced.

Maternal and fetal/neonatal outcomes in pregnancy, delivery and postpartum following bariatric surgery and comparison with pregnant women with obesity: a study protocol for a prospective cohort

BACKGROUND

Being obese can lead to various complications during pregnancy, such as Gestational Diabetes Mellitus (GDM), pregnancy induced hypertension (PIH), Pre-Eclampsia (PE), and Large Gestational Age (LGA). Although bariatric surgery is an effective way to treat obesity, it can also result in complications and may be linked to having small for gestational age (SGA) babies. This cohort study protocol aims to compare the maternal and fetal/neonatal outcomes of two groups of Iranian pregnant women: those who have undergone bariatric surgery and those who are obese but have not had bariatric surgery.

METHODS

In this study Pregnant women (< 14 weeks' gestation) (n = 38 per group) are recruited either from one of the obesity clinic (exposure group = with a history of bariatric surgery) or primary healthcare clinics in Tehran city (comparison group = pregnant women with obesity and and no history of bariatric surgery). Dietary intake and nutrient status are assessed at < 14, 28, and 36 weeks. Maternal and fetal/neonatal outcomes are compared between the two groups, including gestational diabetes, preeclampsia, preterm labor, intrauterine growth restriction, severe nausea and vomiting, abortion, placenta previa and abruption, venous thrombosis, vaginal bleeding, cesarean delivery, meconium aspiration, and respiratory distress. Maternal serum levels of ferritin, albumin, zinc, calcium, magnesium, selenium, copper, vitamins A, B9, B12, and 25-hydroxy Vit D are checked during 24th to 28th weeks. Maternal and neonatal outcomes, including height, weight, head circumference, fetal abnormality, infection, small or large fetus, low birth weight, macrosomia, NICU admission, and total weight gain during pregnancy, are measured at birth. Maternal and offspring outcomes, including weight, height, head circumference, total weight gain during pregnancy, newborn diseases, postpartum bleeding, breastfeeding, and related problems, are assessed 6 weeks after delivery. Child's weight, height, and head circumference are followed at 2, 4, 6, 8, 10, and 12 months after birth. Maternal stress, anxiety, and depression are assessed with the DASS-21 questionnaire, and physical activity is evaluated using the PPAQ questionnaire in the first and third trimesters.

DISCUSSION

By assessing the levels of micronutrients in the blood of pregnant women along with the evaluation of pregnancy outcomes, it is feasible to gain a more accurate understanding of how bariatric surgery affects the health and potential complications for both the mother and the fetus/newborn. This information can help specialists and patients make more informed decisions about the surgery. Additionally, by examining issues such as stress, anxiety, and depression in women undergoing surgery, this study can contribute to recognizing these problems, which can also affect pregnancy outcomes.

The Timing of Pregnancies After Bariatric Surgery has No Impact on Children's Health-a Nationwide Population-based Registry Analysis

PURPOSE

Bariatric surgery has a favorable effect on fertility in women. However, due to a lack of data regarding children's outcomes, the ideal time for conception following bariatric surgery is unknown. Current guidelines advise avoiding pregnancy during the initial weight loss phase (12-24 months after surgery) as there may be potential risks to offspring. Thus, we aimed to analyze health outcomes in children born to mothers who had undergone bariatric surgery. The surgery-to-delivery interval was studied.

MATERIALS AND METHODS

A nationwide registry belonging to the Austrian health insurance funds and containing health-related data claims was searched. Data for all women who had bariatric surgery in Austria between 01/2010 and 12/2018 were analyzed. A total of 1057 women gave birth to 1369 children. The offspring's data were analyzed for medical health claims based on International Classification of Diseases (ICD) codes and number of days hospitalized. Three different surgery-to-delivery intervals were assessed: 12, 18, and 24 months.

RESULTS

Overall, 421 deliveries (31%) were observed in the first 2 years after surgery. Of these, 70 births (5%) occurred within 12 months after surgery. The median time from surgery to delivery was 34 months. Overall, there were no differences noted in frequency of hospitalization and diagnoses leading to hospitalization in the first year of life, regardless of the surgery-to-delivery interval.

CONCLUSION

Pregnancies in the first 24 months after bariatric surgery were common. Importantly, the surgery-to-delivery interval had no significant impact on the health outcome of the children.

Pregnancy and post-partum outcomes of obese women after bariatric surgery: A case-control study

INTRODUCTION

Bariatric surgery (BS) is known to reduce several obesity-related complications during pregnancy, but there is concern that it may increase the risk of maternal-fetal morbidity because of the malabsorption. This study aimed to investigate the impact of restrictive BS on several pregnancy outcomes in comparison with different grades of obesity.

MATERIALS AND METHODS

A single-center retrospective case-control study. All primiparous singleton pregnant women who underwent BS between the previous 1-5 years or with body mass index (BMI) ≥ 30 kg/m² delivering in our center were included. Obstetric and perinatal outcomes were analyzed and compared between the two groups.

RESULTS

Overall, 90 women were included: 30 underwent BS and 60 were obese. The mean pre-pregnancy BMI was 31.0 ± 4.2 kg/m² in the BS group and 38.1 ± 4.3 kg/m² in the control group (p < 0.001). The obese group experienced higher rate of fetal macrosomia (25% vs 6.7%; p = 0.049), gestational hypertension (23.3% vs 3.3%; p = 0.04), preeclampsia (23.3% vs 0%; p = 0.04), gestational diabetes (33.3% vs 6.7%; p = 0.01), and cesarean section (68.3% vs 20%; p < 0.0001). The BS group showed higher frequency of small for gestational age (SGA) (46.7% vs 18.3%; p = 0.006), late preterm delivery (PTD) (33.3% vs 10%; p = 0.009), cholestasis (13.3% vs 1.7%; p = 0.049). Breastfeeding ≥ 6 months was higher among BS mothers (36.7% vs 11.7%; p = 0.007).

CONCLUSIONS

Our findings support the positive impact of BS on several obstetric outcomes, at the expense of a higher frequency of SGA and PTD. BS mothers more frequently achieved the recommended goal of breastfeeding for 6 months compared to obese women.

Reproductive outcomes after bariatric surgery in women

The presence of obesity may significantly influence female fertility through various mechanisms. Impairment of the hypothalamic-pituitary-ovarian axis in obese women may induce anovulation and infertility. Obesity may have an effect on women’s spontaneous and assisted conception rates, increased miscarriage rates, premature labor, stillbirth and perinatal risks, and menstrual irregularity. It has been suggested that weight loss improves reproductive outcomes due to fertility amelioration and an improvement in menstrual irregularity and ovulation. It is still not known which weight reduction procedures (changes in lifestyle, pharmacological management or bariatric intervention) result in optimal outcome on infertility. Currently, bariatric surgery is defined as the best available method for the management of obesity and its associated diseases.

We have analyzed literature facts about effects of bariatric surgery on the function of the hypothalamic-pituitary-ovarian axis, polycystic ovary syndrome (PCOS), anti-Mullerian hormone (AMH) and sexual dysfunction in obesity and pregnancy in obesity. Immediate positive effects of bariatric surgery are evident at the moment, while for long-term outcomes more prolonged follow-up investigations should be done.