It is well-established that gestational conditions, including obesity, can affect offspring, but relatively little is known about how pre-pregnancy weight loss can affect the early life growth trajectory of children born to mothers who have undergone bariatric surgery. Vidhu Thaker, MD, a pediatric endocrinologist at NewYork-Presbyterian and Columbia, recently conducted a study comparing two weight loss procedures, sleeve gastrectomy and Roux-en-Y gastric bypass with no bariatric surgery, to assess how different types of bariatric surgery may influence early childhood weight gain. Below, Dr. Thaker discusses her study and how they can help inform future treatment approaches for childhood obesity.
Study Background
There were two reasons why we chose to focus on mothers who have had bariatric surgery to learn more about how pre-pregnancy weight loss in mothers can affect children's growth trajectory. First, bariatric surgery is a way for patients to achieve sustained weight loss prior to surgery. Second, weight loss resulting from bariatric surgery is not undone as may happen with discontinuation of weight loss medications during pregnancy.
Research Methods
Out of a total of 20,515 deliveries between 2020 and early 2023 at NewYork-Presbyterian and Columbia, there were 450 mothers who had bariatric surgery prior to their pregnancy. About half of babies born at Columbia return for well visits, which provided a large study population of children born to mothers who underwent bariatric surgery as well as children born to mothers who did not.
We compared babies’ birth weight and weight gain in their first two years of life between the three groups: children born to mothers who had sleeve gastrectomy, children born to mothers who had Roux-en-Y gastric bypass, and children born to mothers who did not have bariatric surgery. Among the 450 deliveries involving mothers who had bariatric surgery, 57% had sleeve gastrectomy and 41% had Roux-en-Y gastric bypass. In a sensitivity analysis, we matched for age, race, ethnicity, pre-pregnancy weight, and number of children born to the mother.
Key Findings
At birth, the babies’ weights were approximately the same across the three groups. However, we soon noticed that babies born to mothers who had the gastric sleeve procedure were gaining weight faster than their peers – by their second birthday, they weighed approximately 1.4 kilograms more than children born to mothers who did not have bariatric surgery.
While we observed relatively rapid weight gain in children born to mothers who had sleeve gastrectomy, we did not find the same pattern in children born to mothers who had Roux-en-Y gastric bypass. Children in this group had a body mass index that was closer to the children whose mothers did not have pre-pregnancy bariatric surgery.
Though data on the extent of the mother’s pre-pregnancy weight loss was not available for either type of bariatric surgery for this study, we know that Roux-en-Y gastric bypass is linked to more weight loss than sleeve gastrectomy. It is possible that the magnitude of change in gestational condition brought on by Roux-en-Y gastric bypass is responsible for the offspring’s weight trajectory.
Future Implications
This is the first study to examine longitudinal weight change among children born to mothers who have undergone bariatric surgery. We need to consider how rising obesity rates in adults can impact future generations. There are now more weight loss options than ever before, though unlike weight loss medications that need to be stopped before pregnancy, bariatric surgery is a means of sustained weight loss, that is especially important for individuals of child-bearing age.
These findings open the door to important conversations for physicians to have with their patients about how different types of weight loss methods can affect longitudinal weight gain in their offspring if they are considering having children in the future.
We know that social determinants of health can play a role in overall health, especially body weight. In this study, we did not have access to the dietary data of the participants, their access to food, food insecurity, their living conditions or the feeding practices of the newborns. Therefore, our next steps will include conducting a prospective study to collect information on social determinants of health in similar populations to assess how they can influence early childhood weight gain in children whose mothers have undergone bariatric surgery.
