In a large-scale retrospective study that analyzed more than 55,000 postbariatric surgery pregnancies in France, researchers found that while maternal risks such as gestational hypertension, preeclampsia, and gestational diabetes decreased, neonatal complications such as small-for-gestational-age births, prematurity, and stillbirth were elevated.
Pierre Bel Lassen and colleagues from the Center for Research in Epidemiology and Statistics in Paris, France, examined nationwide data from 2013 to 2022, comparing post-bariatric surgery (post-BS) pregnancies with matched controls and presurgery pregnancies. The researchers found a lower risk of gestational hypertension, a reduction in preeclampsia, and a decrease in gestational diabetes, according to their results published in The Lancet Regional Health - Europe.
However, post-BS pregnancies had an increased risk of small-for-gestational-age births and a higher likelihood of prematurity. Stillbirth risk was also elevated, as was perinatal death risk.
The investigators also found that pregnancy timing influenced outcomes. Conception within 6 months of surgery showed the highest risks of small-for-gestational-age (SGA). Compared with sleeve gastrectomy, gastric bypass was associated with higher risks of SGA and prematurity. Malnutrition further compounded these risks and significantly increased the likelihood of SGA and prematurity.
The researchers wrote: "The risk of prematurity was higher with post-BS than control pregnancies but not when comparing infants born from the same woman pre- and post-BS."
Given these findings, post-BS pregnancies should be considered high risk and necessitate close nutritional and obstetric monitoring, they noted.
They concluded that longer-term studies are needed to evaluate neonatal outcomes over time: "As poor outcomes are mainly mediated by SGA and prematurity, and SGA and prematurity [are] strongly associated with maternal malnutrition, research should focus on investigating nutritional mechanisms and optimizing maternal nutritional care."
Full disclosures can be found in the published research.
