Comparison of the Maternal and Neonatal Outcomes between Women Who Conceived Within 12 Months Following Different Types of Bariatric Surgery (Early Pregnancy) with those Who Conceived Later (Late Pregnancy): A Systematic Review and Meta-analysis of Observational Studies

Abstract

Background: Obesity is linked to an increased risk of a variety of complications during pregnancy and these problems can have a long-term impact on the mother and her child's health. Bariatric surgery (BS) is widely recognised as a safe and effective method of treating obesity and achieving long-term weight loss in obese individuals. However, having BS before becoming pregnant might raise the risk of certain complications. To decrease the chances of these consequences, some clinicians recommend delaying pregnancy for at least 12 to 24 months following surgery. Aim: This systematic review and meta-analysis aims to compare the maternal and neonatal outcomes of women who conceived within 12 months after BS (early pregnancy) with those who conceived later, within more than 12 months after BS (late pregnancy). Methodology: A comprehensive literature search of NUsearch, PubMed and ScienceDirect, was conducted up to 31st July 2021 to identify relevant studies in English. The Newcastle-Ottawa scale was used to assess the quality of the included research. The meta-analysis was performed using the computer program Cochrane Review Manager 5.4. Outcomes of interest were the incidence of gestational diabetes, pregnancy-induced hypertension, preeclampsia, anaemia, caesarean delivery, data of gestational weight (kg), number of preterm births, large or small for gestational age birth, infants with congenital malformations, neonatal mortality, and birth weight (g). Results: Nine observational studies with good quality met the research criteria and were included. Meta-analyses of all maternal and neonatal outcomes found no statistically significant differences between pregnancies occurring prior to or post one-year of weight loss surgery. However, the number of cases recorded in each study and the number of studies included in some meta- analyses are insufficient to arrive at firm conclusions, and there was a degree of heterogeneity in some outcomes among studies. Conclusion: Pregnancy after BS is safe, both for the pregnant mother and the foetus. This study found no evidence to support the advice to postpone conception until the first year after BS and the best timing to get pregnant after surgery is currently uncertain. More detailed knowledge from well-conducted studies with larger samples is needed regarding the effects of early and late conception for the woman and her babies. Also, the long-term follow-up after birth requires further investigation.