Bariatric Surgery

Women who have undergone weight-loss surgery appear to at higher risk of developing complications during pregnancy; their babies seem more likely to born prematurely; small for gestational age, have congenital anomalies and be admitted to intensive care, according to the most comprehensive assessment of how bariatric surgery affects pregnancy outcomes; being presented at this year’s European Congress on Obesity (ECO) in Glasgow, UK (28 April-1 May).
The systematic review and meta-analysis, synthesizing all the available evidence from the scientific literature; compared over 14,800 pregnancies in women who had previously undergone weight-loss surgery with almost 4 million pregnancies in mothers who had not. The authors say that pregnant women with a history of weight-loss surgery should considered as high-risk, be provided additional support throughout pregnancy; mother and baby should monitor closely.

History of bariatric surgery

The findings indicate that women with a history of bariatric surgery; in particular gastric bypass surgery; are at much greater risk of several adverse perinatal outcomes. “These women require specific preconception and pregnancy nutritional support. This highlights the importance of dietary supplements and extra monitoring of fetal growth and development. Health professionals also need training and guidance to able to provide the right advice.”

Pregnant women with obesity are at higher risk of developing complications such as gestational diabetes and hypertension. Weight-loss surgery before pregnancy improves these outcomes; but some bariatric procedures, such as gastric bypass, affect the absorption of micronutrients and may impair fetal development. In the UK, 3 out of every 4 bariatric surgery patients are women; the majority of them are of childbearing age.

Systematic review and meta-analysis

In this study, the researchers conducted a systematic review and meta-analysis of observational studies comparing adverse perinatal outcomes after bariatric surgery to pregnancies without prior weight-loss surgery up to December 2018. Data from 33 articles analyzed; comparing 14,880 pregnancies after bariatric surgery with almost 4 million pregnancies in women who had not undergone surgery.
“It is not clear how weight-loss surgery may influence fetal development, but they know that people who have bariatric surgery are more likely to have micronutrient deficiencies”, says Zainab. “More work needs to done to better understand the causes of these differences so that steps can taken to support women to achieve the best possible pregnancy outcomes for themselves and their babies.”
The authors acknowledge that their findings show observational differences; so no firm conclusions can drawn about cause and effect, and they point to several limitations; including that unmeasured confounding (ie, differences in unmeasured factors which may have affected the health outcomes of the study) may have influenced the results.