Roux-en-Y Gastric Bypass Increases Glycemic Excursions During Pregnancy and Postpartum: A Prospective Cohort Study

Gestational Weight Gain Following Metabolic Bariatric Surgery: A Scoping Review

Metabolic bariatric surgery remains the most effective and durable treatment for severe obesity. Women of reproductive age represent the largest demographic group undergoing these procedures. Metabolic bariatric surgery can have both beneficial and adverse effects on pregnancy outcomes. One of the most common adverse effects is fetal growth restriction. To mitigate these adverse effects, it is crucial to explore lifestyle modifications aimed at promoting a healthy pregnancy. Modifiable factors during pregnancy after metabolic bariatric surgery include the amount of gestational weight gain. The aim of this comprehensive review is to provide an overview of what is known about gestational weight gain in pregnancy after bariatric metabolic surgery. This review is focused on the two most performed procedures: sleeve gastrectomy and Roux-en-Y gastric bypass.

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.

Pregnancy Outcomes After Bariatric Surgery: Importance of Maternal Ferritin on Birth Weight

PURPOSE

The risks carried by pregnancy after bariatric surgery (BS) include small-for-gestational age (SGA) newborn and prematurity. However, the underlying mechanisms are not yet fully understood in pregnant women after BS.

MATERIAL AND METHODS

This single-center retrospective observational cohort study includes all women with a first and single pregnancy after BS who completed at least one clinical and biological nutritional assessment during pregnancy between 2010 and 2016. The quarterly biological assessment comprised blood count, ferritin, calcium, 25OH vitamin D, parathyroid hormone, fasting glucose, albumin, prealbumin, vitamin A, vitamin B12, folic acid, and zinc.

RESULTS

Among 120 pregnancies analysed, two-thirds underwent gastric bypass (Roux-en-Y and one-anastomosis) and one-third a restrictive procedure (adjustable gastric band or sleeve gastrectomy). The median [Q1-Q3] preoperative BMI was 43.8 [41.1-47.7] kg/m2 and the mean age at pregnancy was 32.6 ± 5.3 years. Weight loss and time from surgery to pregnancy were 35.1 ± 15.4 kg and 2.9 [1.3-4.5] years, respectively. Ten women (8%) gave birth prematurely, and 22 newborns (19%) were SGA. Univariate analysis shows that ferritin was significantly higher in mothers with SGA than in those without SGA (35.5 [22.3-69.5] vs. 15 [10-32] ng/ml) at third trimester of pregnancy. Women who received pre-pregnancy nutritional assessment seemed less likely to give birth to a SGA newborn (32% vs. 54%, p = 0.07).

CONCLUSION

Iron supplementation should be carefully prescribed and closely monitored during pregnancy in women who have undergone BS.

Glucose levels measured with continuous glucose monitoring in uncomplicated pregnancies

INTRODUCTION

To characterize glucose levels during uncomplicated pregnancies, defined as pregnancy with a hemoglobin A1c <5.7% (<39 mmol/mol) in early pregnancy, and without a large-for-gestational-age birth, hypertensive disorders of pregnancy, or gestational diabetes mellitus (ie, abnormal oral glucose tolerance test).

RESEARCH DESIGN AND METHODS

Two sites enrolled 937 pregnant individuals aged 18 years and older prior to reaching 17 gestational weeks; 413 had an uncomplicated pregnancy (mean±SD body mass index (BMI) of 25.3±5.0 kg/m2) and wore Dexcom G6 continuous glucose monitoring (CGM) devices throughout the observed gestational period. Mealtimes were voluntarily recorded. Glycemic levels during gestation were characterized using CGM-measured glycemic metrics.

RESULTS

Participants wore CGM for a median of 123 days each. Glucose levels were nearly stable throughout all three trimesters in uncomplicated pregnancies. Overall mean±SD glucose during gestation was 98±7 mg/dL (5.4±0.4 mmol/L), median per cent time 63-120 mg/dL (3.5-6.7 mmol/L) was 86% (IQR: 82-89%), median per cent time <63 mg/dL (3.5 mmol/L) was 1.8%, median per cent time >120 mg/dL (6.7 mmol/L) was 11%, and median per cent time >140 mg/dL (7.8 mmol/L) was 2.5%. Mean post-prandial peak glucose was 126±22 mg/dL (7.0±1.2 mmol/L), and mean post-prandial glycemic excursion was 36±22 mg/dL (2.0±1.2 mmol/L). Higher mean glucose levels were low to moderately associated with pregnant individuals with higher BMIs (103±6 mg/dL (5.7±0.3 mmol/L) for BMI ≥30.0 kg/m2 vs 96±7 mg/dL (5.3±0.4 mmol/L) for BMI 18.5-<25 kg/m2, r=0.35).

CONCLUSIONS

Mean glucose levels and time 63-120 mg/dL (3.5-6.7 mmol/L) remained nearly stable throughout pregnancy and values above 140 mg/dL (7.8 mmol/L) were rare. Mean glucose levels in pregnancy trend higher as BMI increases into the overweight/obesity range. The glycemic metrics reported during uncomplicated pregnancies represent treatment targets for pregnant individuals.

Beyond Weight Loss: A Comprehensive Review of Pregnancy Management following Bariatric Procedures

The increasing prevalence of bariatric surgery among women of childbearing age raises critical questions about the correct management of pregnancy following these procedures. This literature review delves into the multifaceted considerations surrounding pregnancy after bariatric surgery, with a particular focus on the importance of preconception counselling, appropriate nutrition assessment, and the necessity of correct folic acid supplementation. Key areas of investigation include nutrient absorption challenges, weight gain during pregnancy, and potential micronutrient deficiencies. Examining the relationship between bariatric surgery and birth defects, particularly heart and musculoskeletal issues, uncovers a twofold increase in risk for women who underwent surgery before pregnancy, with the risk emphasized before folic acid fortification. In contrast, a nationwide study suggests that infants born to mothers with bariatric surgery exhibit a reduced risk of major birth defects, potentially associated with improved glucose metabolism. In addition, this review outlines strategies for managing gestational diabetes and other pregnancy-related complications in individuals with a history of bariatric surgery. By synthesizing existing literature, this paper aims to provide healthcare providers with a comprehensive framework for the correct management of pregnancy in this unique patient population, promoting the health and well-being of both mother and child.

Increased glycemic variability in pregnant women with Roux-en-Y gastric bypass compared with sleeve gastrectomy

INTRODUCTION

Bariatric surgery is associated with adverse pregnancy outcomes such as reduced birth weight and premature birth. One possible mechanism for this is increased glycemic variability (GV) which occurs after bariatric surgery. The objective of this study was to compare the effect of Roux-en-Y gastric bypass (RYGB) versus vertical sleeve gastrectomy (SG) on GV during pregnancy and to investigate the relationships of GV, type of bariatric surgery and maternal and neonatal outcomes.

RESEARCH DESIGN AND METHODS

Fourteen pregnant women after RYGB and 14 after SG were investigated with continuous glucose monitoring in their second or third trimester in this observational study carried out as part of routine clinical care.

RESULTS

Pregnant women with RYGB had similar mean interstitial glucose values but significantly increased indices of GV and a lower %time in range 3.9-7.8 mmol/L (70-140 mg/dL), compared with SG.

CONCLUSIONS

Pregnant women who have undergone RYGB have greater GV during pregnancy compared with those who have undergone SG. Further research is needed to establish the relationship between GV and pregnancy outcomes to determine the preferred bariatric operation in women of reproductive age, and whether interventions to reduce GV might improve outcomes.

Medical and Psychological Aspects of Pregnancy in Women with Obesity and after Bariatric Surgery

Chronic diseases are potential risk factors for pregnancy duration and neonatal outcomes. This narrative review aimed to summarize the research results on the specifics of pregnancy in women with obesity and after bariatric surgery. PubMed and Google Scholar databases were searched. Systematic reviews, meta-analyses, clinical trials, and references to identified articles from the last ten years (2013-2023) were included. Ultimately, 107 literature items were qualified. It has been shown that women with obesity planning pregnancy should reduce their body weight because obesity is a risk factor for adverse obstetric and neonatal outcomes. Bariatric surgery effectively reduces excessive body weight and the health risks in women with obesity during pregnancy and their offspring. However, at least a year interval between surgery and conception is recommended. An interdisciplinary medical team should provide patient care during pregnancy with knowledge and skills related to people after bariatric surgery. Due to the increased risk of mental disorders, especially depression, it is necessary to constantly monitor the mental state of women and provide psychological support and education on a healthy lifestyle during pregnancy and the postpartum period.

Post-bariatric hypoglycaemia diagnosed during pregnancy

Summary

There is a scarcity of literature relating to post-bariatric hypoglycaemia (PBH) in pregnancy. Recurrent hyperglycaemia and hypoglycaemia can have significant consequences for both the mother and the developing fetus. We describe a case of a young pregnant woman who was diagnosed with symptomatic PBH in the second trimester of pregnancy using continuous glucose monitoring (CGM) 3 years after Roux-en-Y gastric bypass (RYGB) surgery. Instigating a low glycaemic index and complex carbohydrate diet significantly improved the patient's glycaemic excursions. Given that this condition is likely underdiagnosed as a complication of RYGB surgery, a greater awareness of this complication is needed. Patients should be adequately consented pre-operatively for this relatively frequent late surgical complication to enable patients to identify symptoms of this condition at an early stage and seek medical treatment.

Learning points

PBH is an important diagnosis in patients post-RYGB surgery, particularly in women of childbearing age when consequences of both hyperglycaemia and hypoglycaemia during pregnancy can adversely affect both mother and the fetus. Adverse outcomes of recurrent hypoglycaemia to the fetus can include small for gestational age, intrauterine growth restriction and possible impairment of beta cell function. Providing adequate carbohydrate intake to allow growth of the fetus during pregnancy while also attempting to resolve both hyperglycaemia and hypoglycaemia associated with PBH by reducing the intake of simple carbohydrates and high glycaemic index foods can prove challenging. Patients should be adequately consented for late complications of RYGB surgery such as PBH in order to allow early recognition of symptoms and enable prompt treatment.

Comment: pregnancy after bariatric surgery - achievements and open questions

Bariatric surgery confers potential advantages for obese patients, but also risks for pregnancy. Perinatal outcomes may be varying between surgical procedures. This topic was recently addressed by a systematic review in BMC Pregnancy and Childbirth. This commentary will discuss the scientific background and implications for future research.

Use of Continuous Glucose Monitoring in Patients Following Bariatric Surgery: A Scoping Review

The objective of this scoping review was to summarize the emerging literature on the use of continuous glucose monitoring (CGM) in post-bariatric surgery patients, with a focus on its features (e.g., device, mode, and accuracy), as well as purposes and outcomes of utilization. Three databases (PubMed, EMBASE, and Web of Science) were searched to obtain relevant studies. Results suggested that most studies used CGM for 3-7 days under blinded mode. Accuracy data were available in only one study, which reported a mean absolute relative difference of 21.7% for Freestyle Libre. The primary applications of CGM were for elucidating glucose patterns and assessing glycemic treatment outcomes. No study has tested the effect of CGM as an intervention strategy to enhance glucose control.