Glucagon-like protein receptor agonists (GLP-1 RA) have been an exciting new development in the world of weight loss medication. Termed often as “GLP-1s,” these are the class of medications that include semaglutide (brand names Ozempic) and tirzepatide (brand name Mounjaro). These two medications are administered weekly with an injection at home. They are approved for the management of type 2 diabetes. However, the same compounds, marketed under different names (Wegovy and Zepbound, respectively), are approved for weight loss in those with a body mass index (BMI) greater than 30.
These medications have become very popular since they assist those with obesity in managing their hunger and losing weight when in a calorie deficit by increasing satiety and decreasing hunger. Weight loss and maintenance are quite challenging, as the body resists weight loss and increases signals from the brain to increase appetite and preserve its original weight. Thus, when continuing a GLP-1 RA, the brain signals can be quieted, and the weight loss can be maintained.
The side effects of these medications are well-documented and are related to the role of slowing down gastric motility. This predominantly manifests as gastrointestinal symptoms such as nausea, vomiting, and constipation, which can be severe for some people.
With social media posts and news articles describing those who get pregnant after starting these medications, there has been a lot of focus on the occurrence of what some call “Ozempic babies.” However, we have still not confirmed whether this is a true phenomenon, as clinical validation is needed. It is also important to know that we are still learning the implications of these medications on fertility and early pregnancy.
What We Know So Far:
- Studies of weight loss via lifestyle changes or with other weight loss medications (like orlistat) have shown improved chances of natural (spontaneous) fertility. To date, there are no large-scale studies that have concluded the effects of weight loss on chances of pregnancy after fertility interventions. Efforts to gather this information are ongoing, and we will hopefully have more insight in the near future.
- If an individual does not have regular ovulation due to a PCOS-like syndrome, then weight loss by any mechanism can increase the frequency of ovulation and thus the chances of pregnancy. We do not know if there are other benefits of GLP-1 RA medication for fertility in the absence of weight loss.
- GLP-1 RA medications, specifically tirzepatide, may decrease the absorption of the oral contraceptive pill, which could increase the chances of pregnancy if no other contraception is used.
- There are other theories on how GLP-1 RA affects the reproductive system, such as affecting ovulation signals or anti-inflammatory markers in the uterus, but these findings have only been studied in rodents.
GLP-1 Medications and Pregnancy
It is still too early to tell how these medications affect pregnancy.
Semaglutide, tirzepatide, and other GLP-1 RAs are not approved for use in pregnancy and should be stopped prior to conception. As per the manufacturer’s recommendation, semaglutide and tirzepatide should be discontinued at least two months prior to conception. This is based on animal studies that showed using the medication in pregnancy was associated with pregnancy loss as well as an increased rate of birth defects. However, post-marketing surveillance studies are in process to see if this applies to humans.
If you are on semaglutide or tirzepatide, be aware that your chance of natural pregnancy may increase. Thus, you should actively prevent pregnancy with your choice of contraception. If you become pregnant while on the medication, be sure to connect with your care provider and stop taking the medication.
Another important consideration is that when the medication is discontinued, there is often weight regain. We do not have a clear understanding of the effect of weight regain and increased appetite in early pregnancy.
Similar to recommendations regarding pregnancy, the current recommendations are to not take the medication while breastfeeding either, as there is no clear safety data. There have been reports of reduced growth of animal offspring when a short-acting GLP-1 RA was used during lactation, but human data is lacking.