Pregnancy following Bariatric Surgery: feto-placental and neonatal considerations
File(s)
Author(s)
Maric, Tanya
Type
Thesis
Abstract
The prevalence of obesity in pregnancy is continuing to rise. Obese women have a three-fold risk of developing gestational diabetes mellitus (GDM), large for gestational age neonates (LGA) and the risk of preeclampsia (PE) doubles for every 5-7kg/m2 increase in pre-pregnancy bodyweight.
Bariatric Surgery (BS) is an effective treatment for sustained weight loss with a rapid increase in the number of procedures performed in the last 6 years. Long-term studies in non-pregnant populations have demonstrated that BS significantly improves insulin sensitivity and type 2 diabetes mellitus (T2DM) leading to long-term remission of the condition and improves cardiovascular outcomes.
Numerous retrospective studies have shown that pregnancy following BS is associated with a reduced risk of GDM/LGA neonates and hypertensive disorders, but increased risk of small for gestational age (SGA) neonates and late preterm delivery, relative to pregnancies with similar maternal pre-surgery and pre-pregnancy BMI. The increased risk of SGA babies appears to be higher in patients who have undergone a malabsorptive procedure. The underlying causes of fetal growth restriction in this group is unknown and warrants further investigation to enable the development and application of preventative strategies.
This study is a prospective, observational study aiming to investigate the effect of BS on perinatal growth and metabolic profile. We investigated the intra-uterine environment, metabolic profile and body composition of offspring of women who had undergone a previous BS compared to women without previous surgery.
• Using 2D ultrasound, the intra-uterine fetal environment was assessed by measuring fetal growth velocity and feto-placental Doppler indices, longitudinally, at four timepoints during gestation to assess whether placental dysfunction plays a role in the reduction in fetal growth, seen in this population.
• The intra-uterine fetal body composition was determined by calculating fractional limb (thigh and arm) volumes using 3D ultrasound and software. This was followed by anthropometric measurements at birth.
• In order to assess the neonatal metabolic profile at delivery, neonatal insulin resistance from venous cord blood using HOMA-IR, a surrogate marker of insulin resistance, peptides involved in glucose metabolism and inflammatory markers were measured.
• Finally, we investigated the placental expression of insulin-like growth factors, their binding proteins and glucose transporters as well as other peptides known to influence fetal growth.
Bariatric Surgery (BS) is an effective treatment for sustained weight loss with a rapid increase in the number of procedures performed in the last 6 years. Long-term studies in non-pregnant populations have demonstrated that BS significantly improves insulin sensitivity and type 2 diabetes mellitus (T2DM) leading to long-term remission of the condition and improves cardiovascular outcomes.
Numerous retrospective studies have shown that pregnancy following BS is associated with a reduced risk of GDM/LGA neonates and hypertensive disorders, but increased risk of small for gestational age (SGA) neonates and late preterm delivery, relative to pregnancies with similar maternal pre-surgery and pre-pregnancy BMI. The increased risk of SGA babies appears to be higher in patients who have undergone a malabsorptive procedure. The underlying causes of fetal growth restriction in this group is unknown and warrants further investigation to enable the development and application of preventative strategies.
This study is a prospective, observational study aiming to investigate the effect of BS on perinatal growth and metabolic profile. We investigated the intra-uterine environment, metabolic profile and body composition of offspring of women who had undergone a previous BS compared to women without previous surgery.
• Using 2D ultrasound, the intra-uterine fetal environment was assessed by measuring fetal growth velocity and feto-placental Doppler indices, longitudinally, at four timepoints during gestation to assess whether placental dysfunction plays a role in the reduction in fetal growth, seen in this population.
• The intra-uterine fetal body composition was determined by calculating fractional limb (thigh and arm) volumes using 3D ultrasound and software. This was followed by anthropometric measurements at birth.
• In order to assess the neonatal metabolic profile at delivery, neonatal insulin resistance from venous cord blood using HOMA-IR, a surrogate marker of insulin resistance, peptides involved in glucose metabolism and inflammatory markers were measured.
• Finally, we investigated the placental expression of insulin-like growth factors, their binding proteins and glucose transporters as well as other peptides known to influence fetal growth.
Version
Open Access
Date Issued
2018-11
Date Awarded
2019-08
Copyright Statement
Creative Commons Attribution NonCommercial Licence
Advisor
Savvidou, Makrina
Publisher Department
Department of Surgery & Cancer
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)