After bariatric surgery, it is recommended to wait at least 12-18 months (with some guidelines recommending to wait two full years) before considering pregnancy. This is because rapid weight loss and a higher risk for nutritional deficiencies occurs during this phase, which may be a poor environment for fetal development. However, a recent study suggests that waiting two years may not be enough.
The study, published in JAMA Surgery, looked at data from women and their infants in Washington state who had had bariatric surgery (n=1859), and compared them to women and their infants who had not had bariatric surgery (n=8437). They found that babies who were born to mothers who had had bariatric surgery had a 57% higher risk of prematurity, 25% higher risk of needing to be admitted to the NICU, 93% higher risk of being small for gestational age.
However, when 4 years or more had elapsed since bariatric surgery, the risk of these outcomes was lower when compared to women where 2 years or less had elapsed. Specifically, the risk for babies born less than 2 years after bariatric surgery was 48% higher for prematurity and 54% higher for NICU admission, compared to babies born to mothers where 4 years or more had elapsed (the difference for being small for gestational age was not significant). For babies born in the 2-4 year window after bariatric surgery, the authors note that the prevalence of prematurity and NICU admission was not meaningfully different from babies born to women who had not had bariatric surgery.
So how do we interpret these data? Well, we already knew that the risks identified in this study exist for babies born to mothers after bariatric surgery, but we need to remember that there are benefits to pregnancy outcomes after bariatric surgery as well – for example, less babies born large for gestational age, less labor and delivery complications, lower risk of C section birth, lower risk of gestational diabetes and high blood pressure in pregnancy. However, based on these data, it may be better to wait even longer than two years after bariatric surgery before conceiving.
