Are GLP-1s the Newest Fertility Treatment?

First, there were “Ozempic babies.” Now, there is also Ozempic-before-baby.

Unplanned pregnancies are still regularly being reported among people using glucagon-like peptide 1 receptor agonist (GLP-1 RA) drugs, and now fertility specialists are increasingly incorporating the medicines into preconception care plans.

The specialists say their colleagues in other areas of medicine may have an opportunity, too, to talk about weight loss using these new drugs in terms of reproductive health. Motivation and compliance can transform when the goal isn’t simply weight loss but having children.

“We have this really special moment to help patients be healthier, in order to be healthier for their kids,” said Christina Boots, MD, MSci, an associate professor of reproductive endocrinology and infertility at Northwestern University’s Feinberg School of Medicine, Chicago. “And I think that’s also a very motivating moment. It may be hard to get up and go for a run to make my jeans fit better, but when I think about it in terms of, ‘this might someday help my future daughter,’ that is a whole different level of motivation.”

Discussing obesity treatment can be a delicate conversation, but one that would be beneficial to have with any patient of reproductive age. Here’s why, what to know about the current lengthy list of unknowns and risks, and some options for approaching the topic with patients.

What Fertility Docs Are Doing

While overweight and obesity are consistently linked to fertility and pregnancy outcomes, Boots predicts the biggest impact of GLP-1 weight loss for fertility among women will be a specific subset: Those who are not cycling regularly, such as those with polycystic ovary syndrome (PCOS).

“The women who are cycling regularly who have very unexplained infertility and no other comorbidities like high blood pressure or something else going on, I don’t think it’s going to help their fertility very much at all,” she said “It might, but I think there’s probably something else going on in her tubes or with her eggs or his sperm, but it has nothing to do with her metabolic health.

Women who aren’t cycling regularly will benefit, but those with truly unexplained fertility probably won’t, she said.

In their recent narrative review on treating obesity and fertility with GLP-1 RAs that appeared in Fertility and Sterility, Boots and co-author Alyse S. Goldberg, MD, an endocrinologist with the University of Toronto, Toronto, Ontario, Canada, advocate for the use of GLP-1s as a go-to treatment for obesity as part of preconception care by reproductive endocrinologists, calling the drugs “the most effective, least invasive means of weight loss.”

The paper is timely and necessary because use of GLP-1s is only going to increase, said Patricia Jimenez, MD, an associate professor of obstetrics and gynecology at Washington University School of Medicine in St. Louis, Missouri, in an email to Medscape Medical News.

“GLP-1 RAs are becoming a larger part of my practice. More patients are either using them already or interested in using them,” said Jimenez, who is board certified in reproductive endocrinology, obstetrics and gynecology, and obesity medicine. “I specifically see patients to discuss this and do prescribe antiobesity medications, not only GLP-1 RAs. Often this is with people with PCOS who are not planning to conceive soon or patients willing to delay fertility treatment [by] 3-6 months.”

Treating obesity is also important for women who are seeking in vitro fertilization, Boots said, because many IVF clinics have a body mass index cutoff of 40 kg/m².

Like Jimenez’s approach, Boots and Goldberg call for comprehensive obesity care beyond the use of medication, including nutritional counseling and mental health support. Those supports are important during the transition off of GLP-1 medications, which poses a risk for rapid weight regain. That’s even with the potential support of taking metformin, which Boots often prescribes as a bridge.

Semaglutide should be stopped at least 2 months prior to conception, and tirzepatide should be stopped 1 month prior to conception, according to the manufacturers. (Boots and Goldberg listed the Canadian label recommendation for stopping tirzepatide, noting there is no suggested timeline for stopping prior to conception on the US label.)

Numerous studies have shown rapid weight regain is common when stopping GLP-1s, which presents a unique set of risks for pregnant women including early pregnancy loss, gestational diabetes, preeclampsia, and nonelective cesarean delivery.

Weighing Risks, Benefits, and Unknowns

Early looks at small human data sets, mostly involving semaglutide and earlier short-acting GLP-1s, and their impact on the risk for birth defects are “reassuring,” Boots said.

“But birth defects are just one small aspect. There’s also metabolic health and things like that long-term. Understanding what it does to the growing baby and the proximity of that medication to that growing baby is really important to see, and can’t be answered with animal studies, not perfectly anyway,” Boots said.

There are no published reports, from clinical trials nor case collections, examining the use of tirzepatide among pregnant people.

“One of the most important questions we need to answer is the preconception safety of these medications, and that includes safety for men,” said Joshua Halpern, MD, MS, an adjunct assistant professor of urology at Northwestern University’s Feinberg School of Medicine, and chief scientific officer for Posterity Health, in an email to Medscape Medical News.

“For example, a recent study found that men who were taking metformin, another popular medication for diabetes, were more likely to have children with birth defects, compared with those who were not taking the medication,” Halpern said. “Further studies are needed to determine whether a similar effect might hold true for the GLP-1 agonists.”

Small early studies on sperm are encouraging, Halpern said, suggesting that GLP-1 use may be beneficial, but a better understanding of direct effects is needed.

Among women, there may be cases where continuing use of a GLP-1 during pregnancy may offer benefits that outweigh risks, Boots suggested. Manufacturers have also created pregnancy exposure registries to measure the safety of their therapies during pregnancy.

“I have a group of patients whose sugars are so well controlled on these medications, but as soon as they come off, they get weight regain and their glucose is just so poorly controlled,” she said. “There may be a group of women where the benefits of glucose control outweigh the risks of being on the medication the whole pregnancy.”

The list of important unknowns also includes a need to examine how rapid weight loss may impact ovulation rates and spontaneous conception, as well as miscarriage rates, birth weight, and metabolic health of the child.

More detailed rebound weight gain data is coming next year, with additional analysis expected as well on birth weight and pregnancy outcomes, said Jacqueline Maya, MD, first author of the research abstract presented at this year’s American Diabetes Association conference that examined gestational weight gain among people with preexisting type 2 diabetes who were exposed to GLP-1s during pregnancy. The study included 47 exposed pregnancies (based on prescription records and electronic chart information) and compared gestational weight gain to 141 unexposed matched pregnancies. Among the exposed group, 62% exceeded recommended weight gain, compared with 41% in the unexposed group. On average, gestational weight gain in exposed pregnancies exceeded that among matched unexposed pregnancies by about 6 pounds.

The team is now working with an additional data set to examine exposed pregnancies among people with obesity, said Maya, an instructor of pediatrics at Mass General Hospital and Harvard School of Medicine. She is particularly interested in examining weight trajectories during pregnancy to see how they may affect fetal outcomes. Her team’s current project also will likely include analysis to examine other variables like postpartum weight gain and adiposity characteristics of the baby.

Maya said the team hopes to have more to report at the American Diabetes Association conference in June next year.

Offer the Conversation

Using a GLP-1 for weight loss takes time, usually around 1 year to reach a plateau. Boots encouraged nonfertility providers to ask patients of reproductive age about their family plans as an opening.

“I hope for all primary care doctors and gynecologists, that with any patient of reproductive age, you should be bringing this up, asking, ‘Have you thought about having kids? Are you thinking about it soon?’ And if they say they are sometime in the near future, then you can say, ‘Is it OK if I bring up your weight?’ And you should ask permission.”

If the patient declines, it’s OK to bring it up again at a future visit.

“People with obesity have often experienced negative weight bias that impacts their care,” Jimenez said. “Treat obesity as a disease, not a personal failing. Ask permission to discuss weight with the patient beforehand. If they say no, respect that answer. This goes a long way in developing a positive relationship, so they return for care and may be willing to discuss later.” 

When patients are open to the conversation, Boots suggests not focusing on the potential for poor outcomes, and instead perhaps saying, “If you’re thinking about having a baby in 5 years, optimizing your health now will not only make your pregnancy healthier, but your child healthier long-term.”

Discussing contraception plans remains important. People starting semaglutide or tirzepatide should use contraception other than oral birth control for 4 weeks while starting the medicine and for 4 weeks after each dose increase.

Boots said that the contraception conversation is particularly important because many people have come to deeply believe that they are infertile and, thus, may perhaps think contraception advice doesn’t apply to them. Maya hypothesized that behavioral changes following weight loss may also be a pathway toward pregnancy.

“Pregnancy while on GLP-1 RAs does happen. I always have a discussion about this possibility and contraception. This can sometimes be challenging for people with infertility to consider,” Jimenez said. “Explaining the risks, benefits, and unknowns can help. As the [Fertility and Sterility] paper describes, the limited data available has not shown increased fetal or maternal complications. We need more high quality data to better understand the impact of exposure or use around the time of conception and during pregnancy.”

It’s also important to introduce the idea to patients that they may someday need to come off the medications, such as when they are ready to have children, and how important lifestyle and behavioral changes will be at that time, Maya said.

“We do know what the alternative is, and we do know what the risks of obesity are,” she said. “So, it’s a tug and pull. We’re not starting off with healthy. We’re starting off with a disease that is physically and emotionally very difficult for the patient, especially when it starts in childhood.”