A new research letter in JAMA tells us that more new mothers are using GLP-1s for weight management. The rise of use in this context is dramatic – roughly 500% between 2022 and 2024.

Note that these data come from Denmark. There, we estimate the per capita use of GLP-1s for obesity is somewhat less than it is in the U.S. It’s also important to note that this percentage increase appears so large because the use in 2022 was so small. In 2022, the number of new mothers using GLP-1s for weight management was 34 per 10,000 new births. Two years later, that number was 173 per 10,000 new births. That’s 1.7% of new mothers using semaglutide for weight management.

National Registry Data

These observational data come from Danish national registries. Every new birth is recorded at an individual level. These data were cross-linked to a national prescription registry. So researchers could identify every woman who filled a prescription for Wegovy (semaglutide) within 182 days after giving birth.

These data sources are quite robust. But they still have limitations. Filling a prescription is not the same thing as actually using it. Regardless, we see these data as quite useful.

What Are the Implications?

These should prompt us to think hard about the implications of an ongoing rise in the use of medicines like semaglutide by women who have recently had a baby. The authors of this research make a point that we actually know very little about the risks and benefits of these drugs in this setting:

“The postpartum period represents a phase of maternal physiological and hormonal transition, during which the safety of semaglutide use is poorly documented. Further, the potential short- and long-term risks to the breastfeeding infant have been insufficiently studied.”

This is especially true when you consider that the clinical trials for semaglutide in obesity generally excluded new mothers for reasons of caution. The FDA-approved prescribing information for Wegovy does not give sharp reasons for concern, but it makes the paucity of information quite clear:

“There are no data on the presence of subcutaneously administered semaglutide or its metabolites in human milk, the effects on the breastfed infant, or the effects on milk production. Semaglutide was present in the milk of lactating rats. When a drug is present in animal milk, it is likely that the drug will be present in human milk (see Data). The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Wegovy and any potential adverse effects on the breastfed infant from Wegovy or from the underlying maternal condition.”

The Underlying Need

It is not good enough to say that we don’t know much about use in this setting. In the early days of drug development, it makes sense to avoid exposing new mothers to a new drug with an uncertain safety profile. But now we know much more about these drugs. And now, we can see that they may be important for some patients in this setting.

The need for help with weight management after having a child is very real. It can be vitally important for the health of a woman who has just had a child. Broad generalizations about what a woman “should” or “shouldn’t” do in the context of obesity and recent childbirth are frankly insulting when they are uninformed by good clinical data. One size does not fit all.

Medical researchers and pharmaceutical companies should do better.

Click here for the paper in JAMA, here, here, and here for further perspective. For an excellent discussion of a women’s health perspective on managing obesity, click here.

Theodore Lambert DeCamp as An Infant, painting by Joseph DeCamp / WikiArt