Impact of maternal bariatric surgery on offspring perinatal cardiac function: A prospective study.

OBJECTIVE: To assess perinatal cardiac function in offspring of women with previous bariatric surgery and examine its association with maternal glucose control. DESIGN: Prospective study. SETTING: Maternity unit, UK. POPULATION: Fifty-four fetuses/neonates; 29 of post-bariatric surgery women and 25 of women without surgery. METHODS: Prospective, longitudinal observational study of pregnant women with and without previous bariatric surgery, matched for early pregnancy body mass index. Cardiac function of all offspring was assessed by two-dimensional conventional, spectral tissue Doppler and speckle-tracking echocardiography at 35-37 weeks of gestation and at 5-7 weeks of age. Maternal glycated haemoglobin (HbA1c) was measured at 27-30 weeks of gestation. Maternal demographics and fetal/infant cardiac function indices were compared between the groups. Correlation coefficient (r) is reported. MAIN OUTCOME MEASURES: Fetal/infant cardiac function indices. RESULTS: Compared with no-bariatric neonates, offspring of post-bariatric women were smaller at birth (birthweight centiles: 64.96 ± 36.41 versus 40.17 ± 27.99; p = 0.007). There were no significant differences in fetal/infant cardiac function indices and perinatal cardiac changes, between groups. There was a positive correlation between maternal HbA1c and fetal left ventricular (LV) longitudinal strain (r = 0.33) and LV longitudinal strain rate (r = 0.29), suggesting an inverse relation between HbA1c and fetal LV systolic function, but this was mainly seen in offspring of women with no previous bariatric surgery (r = 0.56 and r = 0.50, respectively). CONCLUSIONS: Maternal bariatric surgery does not appear to inadvertently affect the offspring cardiac performance. We found an inverse correlation between maternal HbA1c levels and fetal LV systolic function but this was mainly seen in the no-bariatric pregnancies.

Gestational Weight Gain in Pregnancies Following Bariatric Surgery.

INTRODUCTION: To compare the gestational weight gain (GWG) between women with previous bariatric surgery and those without and investigate whether GWG correlates with birthweight (BW) or delivery of a small-for-gestational-age (SGA) neonate. MATERIALS AND METHODS: Prospective, longitudinal study, include 100 pregnant women with previous bariatric surgery and 100 without weight loss surgery, but with similar early-pregnancy body mass index (BMI). In a sub-study, 50 of the post-bariatric women were also matched to 50 women without surgery, but early-pregnancy BMI similar to the pre-surgery BMI of the post-bariatric ones. All women had their weight/BMI measured at 11-14 and 35-37 weeks of gestation, and the difference in maternal weight/BMI between the two time points was expressed as GWG/BMI gain. Associations between maternal GWG/BMI gain and birthweight (BW) were examined. RESULTS: Compared to no bariatric women with similar early-pregnancy BMI, post-bariatric women had similar GWG (p = 0.46), and the number of women with appropriate, insufficient, and excessive weight gain was comparable between groups (p = 0.76). However, post-bariatric women delivered smaller babies (p < 0.001), and GWG was not a significant predictor of BW or of delivering a SGA neonate. Compared to no bariatric women with similar pre-surgery BMI, post-bariatric ones had higher GWG (p < 0.01) but still delivered smaller neonates (p = 0.001). CONCLUSIONS: Post-bariatric women seem to have similar or greater GWG compared to women without surgery matched for early-pregnancy or pre-surgery BMI, respectively. Maternal GWG was not associated with BW or higher prevalence of SGA neonates seen in women with previous bariatric surgery.

Effect of postbariatric maternal weight loss and surgery to conception interval on perinatal outcomes of nulliparous women.

BACKGROUND: Bariatric surgery is associated with an increased risk of delivering a small neonate. The role of maternal weight loss and surgery to conception interval is unclear. OBJECTIVES: To investigate the effect of maternal weight loss, as a result of bariatric surgery, and surgery to conception interval on fetal growth and birthweight (BW). SETTING: Inner London Teaching Hospital METHODS: We studied prospectively nulliparous women with previous bariatric surgery. Information on type, time, and presurgery weight was obtained. Surgery-to-conception interval was calculated as the time between surgery and conception, defined as the fourteenth day of the pregnancy dated by first trimester ultrasound scan. In the first trimester, maternal weight was measured. Assessment of maternal weight change between presurgery and first trimester of pregnancy was defined as total weight loss (TWL) (%). Fetal ultrasound scans were performed twice; 30-32 and 35-37 weeks' gestation and estimated fetal weight (EFW) was calculated. Fetal growth rate was calculated as the ratio of EFW increase (in grams) between 30-32 and 35-37 weeks divided by the time interval (in days) between the 2 examinations. BW was recorded. RESULTS: The study included 54 pregnant women, 26 with a restrictive procedure (gastric band or vertical sleeve gastrectomy) and 28 with a gastric bypass. Surgery to conception interval was not a significant predictor of the offspring's growth. Maternal TWL was a significant predictor of fetal growth rate (P = .04) and predictor of BW (P = .005), even after adjustment for confounders. CONCLUSIONS: Maternal weight loss, as a result of bariatric surgery, has an inverse correlation with fetal growth rate and BW.

Fetal fractional limb volumes in pregnancies following bariatric surgery.

INTRODUCTION: Obesity rates have reached an epidemic level and bariatric surgery is the most effective method of sustainable weight loss. Pregnancy following bariatric surgery is associated with an increased prevalence of small babies. The objective of the study is to compare the fetal fat distribution, as assessed by fractional arm and thigh volume using three-dimensional ultrasonography, in pregnancies following maternal bariatric surgery with those without such history. MATERIAL AND METHODS: This is a prospective, longitudinal, observational study conducted in a Maternity Unit in the UK. The study included 189 pregnant women; 63 with previous bariatric surgery [27 restrictive (13 with gastric band, 14 with sleeve gastrectomy) and 36 malabsorptive procedures] and 126 with no previous surgery but similar maternal booking body mass index. Fetal arm and thigh volume were obtained at 30-33 and 35-37 weeks' gestation and fractional limb volumes were calculated using a commercially available software. Women underwent a 75 g, 2 h oral glucose tolerance test at 28-31 weeks of gestation. RESULTS: Overall, adjusted fetal arm and thigh volume were smaller in the post-bariatric, compared to the no surgery, group and this was more marked in women who had undergone a previous sleeve gastrectomy (P < .001 and P = .002, respectively) or a malabsorptive procedure (P < .001 for both). There was a strong positive correlation between maternal fasting/post-prandial (2 h) glucose levels, at the time of the oral glucose tolerance test, and arm and thigh volume at both 30-33 and 35-37 weeks (P < .01 for all). CONCLUSIONS: The study has demonstrated that in the third trimester of pregnancy, fetuses of women with previous bariatric surgery have smaller fractional limb volumes, therefore less soft tissue, compared to fetuses of women without such surgery and this may be related to the lower maternal glucose levels seen in the former pregnancies.

Longitudinal metabolic and gut bacterial profiling of pregnant women with previous bariatric surgery.

OBJECTIVE: Due to the global increase in obesity rates and success of bariatric surgery in weight reduction, an increasing number of women now present pregnant with a previous bariatric procedure. This study investigates the extent of bariatric-associated metabolic and gut microbial alterations during pregnancy and their impact on fetal development. DESIGN: A parallel metabonomic (molecular phenotyping based on proton nuclear magnetic resonance spectroscopy) and gut bacterial (16S ribosomal RNA gene amplicon sequencing) profiling approach was used to determine maternal longitudinal phenotypes associated with malabsorptive/mixed (n=25) or restrictive (n=16) procedures, compared with women with similar early pregnancy body mass index but without bariatric surgery (n=70). Metabolic profiles of offspring at birth were also analysed. RESULTS: Previous malabsorptive, but not restrictive, procedures induced significant changes in maternal metabolic pathways involving branched-chain and aromatic amino acids with decreased circulation of leucine, isoleucine and isobutyrate, increased excretion of microbial-associated metabolites of protein putrefaction (phenylacetlyglutamine, p-cresol sulfate, indoxyl sulfate and p-hydroxyphenylacetate), and a shift in the gut microbiota. The urinary concentration of phenylacetylglutamine was significantly elevated in malabsorptive patients relative to controls (p=0.001) and was also elevated in urine of neonates born from these mothers (p=0.021). Furthermore, the maternal metabolic changes induced by malabsorptive surgery were associated with reduced maternal insulin resistance and fetal/birth weight. CONCLUSION: Metabolism is altered in pregnant women with a previous malabsorptive bariatric surgery. These alterations may be beneficial for maternal outcomes, but the effect of elevated levels of phenolic and indolic compounds on fetal and infant health should be investigated further.

Maternal, neonatal insulin resistance and neonatal anthropometrics in pregnancies following bariatric surgery.

OBJECTIVE: An increasing number of women present pregnant having undergone bariatric surgery, a popular treatment for sustainable weight loss. The aim of the study was to investigate the effect, if any, of bariatric surgery on maternal and neonatal insulin resistance (IR) and neonatal body fat composition. METHODS: Maternal IR, at 28 weeks of gestation during 2-hour 75 g oral glucose tolerance test (OGTT), neonatal IR, from umbilical cord venous blood, and neonatal birthweight and body fat composition (calculated by measuring skin folds) at birth were evaluated in 41 post-bariatric and 82 pregnant women with similar early pregnancy body mass index but no history of such surgery. Insulin resistance was assessed using the homeostasis model assessment of IR (HOMA-IR). RESULTS: In the post-bariatric surgery group, compared to the no surgery group, maternal HOMA-IR (1.15 [1.04-2.07] vs 2.20 [1.53-3.38]; p < 0.01), neonatal birthweight (p < 0.01) and body fat (p < 0.01) were significantly lower whereas neonatal cord HOMA-IR was similar (1.29 [0.65-2.39] vs 1.19 [0.46-1.93]; p = 0.49). In the no surgery group, there was a positive correlation between maternal and neonatal HOMA-IR (p = 0.03) and between neonatal HOMA-IR and body fat (p < 0.01). However, no such significant correlations were detected in the post-bariatric surgery group. CONCLUSION: Pregnancy following bariatric surgery is associated with a reduction in maternal IR and altered neonatal body composition with significantly lower birthweight and adiposity but no improvement in cord IR.