Weight loss injections can unintentionally improve fertility
Some women using weight loss injections, such as Ozempic and other GLP-1 similar drugs, are reporting getting a big surprise: pregnancy even though they were previously diagnosed as infertile and some even on birth control. Do a search on social media or the internet for “Ozempic babies” and you will find plenty of anecdotal stories of women getting pregnant while on weight loss injections.
Because of the way weight loss injections work, there are reasons they may lead to more pregnancies. However, there is concern about the use of these drugs during early pregnancy. If you are taking drugs for weight loss, you should be aware that they may simultaneously improve fertility as well as decrease the effectiveness of oral birth control.
Losing weight can improve ovulation
Being overweight or obese can reduce your fertility by causing your menstrual cycles to be irregular or infrequent. Your chances of having a baby drops dramatically with a BMI (body-mass index) greater than 35. But losing weight can help restore your menstrual cycles and fertility. Studies have shown that weight loss of just 5% to 10% of your body weight can dramatically improve ovulation and pregnancy rates.
Glucagon-like peptide-1 (GLP-1) and GLP-1 Receptor Agonists (RAs) are a class of injectable medications that were originally created to treat type 2 diabetes. More recently, however, GLP-1 drugs are increasingly being used to treat obesity, regardless of a diagnosis of type 2 diabetes. GLP-1 drugs mimic hormones in the gut involved in insulin regulation and appetite, helping control blood sugar levels, reduce hunger, and promote weight loss. On average, people taking weight loss injections can lose 15% to 20% of their body weight, clinical trials show.
It’s no surprise, then, that many women on GLP-1 weight loss drugs are finding their cycles returning to more regular frequency. And when women ovulate normally, they have a better chance of getting pregnant. Certain gynecologic conditions, like polycystic ovarian syndrome (PCOS), often coincide with obesity and difficulty conceiving. Women with PCOS struggle with irregular ovulation and about 70% are also obese. Those who choose to take weight loss injections may also start ovulating normally.
Possible effects of weight loss injections on contraceptives
To compound the possibility of improved fertility from weight loss injections, there is also some evidence to suggest that GLP-1 drugs might interfere with the effectiveness of hormonal contraceptives you take to prevent pregnancy, such as birth control pills. Ozempic and two similar medicines with a different active ingredient, Mounjaro and Zepbound, carry warnings about this potential side effect in their prescribing information.
While this phenomenon of less effective birth control needs more study, the theory rests on the fact that weight loss medications slow down stomach emptying, affecting how food and oral medications can be absorbed. This can cause birth control pills taken by mouth to not be absorbed consistently, especially each time the dose of weight loss injections are increased. If you are on weight loss injections, it is recommended that you also use an alternative form of birth control.
What to do if you get pregnant on weight loss drugs
Little is known about the safety of weight loss injections during pregnancy. The joy you might experience in discovering you are pregnant may come with anxiety about the unknowns, as these medicines haven’t been studied on pregnant women. The drugs’ makers, Novo Nordisk and Eli Lilly, excluded women who were pregnant or planned to become pregnant from their clinical trials, a common practice when testing new medicines. Right now, not enough human data is available to establish whether these drugs are associated with major birth defects, miscarriage, or adverse outcomes for either the mother or the baby.
Because of the unknowns about weight loss injections taken in pregnancy, our reproductive endocrinologists counsel their patients to be fully off of them for 2 months before attempting pregnancy to allow the drugs to fully leave your body. If you are on weight loss injections and suddenly find yourself pregnant, we recommend that you discontinue them immediately and let your obstetrician or fertility expert know. You will need to be monitored closely during pregnancy.
