Maternal Bariatric Surgery and Offspring Health: A Sibling Matched Analysis Comparing Offspring Born before and after the Surgery †

(1) Background: Due to the global escalation in the prevalence of obesity, bariatric surgeries have become a popular solution in many western countries. The aim of the current study was to compare offspring health and the obesity of women before and after undergoing bariatric surgeries. (2) Methods: A retrospective population-based study was performed, including all singleton deliveries which occurred at a tertiary medical center between the years 1991–2021. Among women who had bariatric surgeries, the health of the offspring born before and after the surgery were compared. The offspring were followed up until the age of 18 years, and their hospitalization records were summarized. The incidence of hospitalization with either endocrine, cardiac, respiratory, neurologic, or infectious diagnoses were compared between the groups, as well as offspring obesity. Multivariable Cox proportional models were used to match between siblings and to address confounding variables, including maternal age, gestational age at delivery, fertility treatment, smoking and pregnancy hypertensive disorders. (3) Results: The study population included 3074 deliveries of women who underwent bariatric surgeries (1586 were before and 1488 after the surgery). Offspring born after maternal bariatric surgeries were at a comparable risk for most morbidities, besides endocrine-related morbidities (3.1% vs. 5.0%, OR = 1.61; 1.1–2.35) and obesity (2.5% vs. 4.1%, OR = 1.63; 1.08–2.48). The risk for these morbidities was higher among the offspring of mothers after, vs. before, the surgery, despite adjustment for maternal age and other confounding variables. (4) Conclusions: While bariatric surgeries are considered an effective treatment for obesity, it seems to have less of an effect on the offspring of women who underwent such surgeries. Other persistent factors are most likely associated with the offspring’s risk for morbidities, especially endocrine morbidities and obesity, which remain even though the mother underwent bariatric surgeries.