'Ozempic babies' are surprising women taking weight loss drugs. Doctors think they know why.

Women are getting pregnant, in most cases unintentionally, they say, while taking weight loss medications like Ozempic and Mounjaro, despite being on birth control or dealing with years of fertility issues.

Facebook groups, Reddit threads and TikTok videos are connecting women who are pregnant with or already had an “Ozempic baby” or “Mounjaro baby,” as they have come to be called, and want to share their surprise pregnancy experiences.

“I got pregnant on Ozempic & was on the pill! Baby boy is due in June,” one person commented on a TikTok. “My surprise Ozempic baby is almost 4 months old and thankfully very healthy!” another wrote.

Deb Oliviara, 32, started taking Ozempic the day after Thanksgiving to lose excess weight that had been affecting her mental health. She wasn’t consistent with taking her birth control pill, but that didn’t concern her much because she has a history of unidentified fertility issues that has made it difficult to get pregnant.

Just two months after starting the medication, and the same week she hit her goal weight, Oliviara learned she was pregnant. “We were open to the idea, but definitely not trying,” she said. “It was very much a surprise and the only pregnancy, aside from my first, that didn’t come after a loss.”

This is Oliviara’s sixth pregnancy with only two living children. She has had a first trimester loss, second trimester loss and a stillbirth. Now 10 weeks along, Oliviara and her baby are healthy.

Reproductive and obesity medicine experts told USA TODAY that they’re also noticing the trend in their offices, which they say is likely happening for two reasons. First, weight loss is correcting hormonal imbalances caused by obesity and metabolic disorders and thus boosting fertility. Second, certain drugs may be reducing the efficacy of birth control pills, increasing the chances of pregnancy.

Yet, under no circumstances should women use weight loss drugs to get pregnant, experts warn. Studies on rats, rabbits and monkeys showed that these medications, if taken while pregnant, can lead to miscarriage and birth defects. (No studies have been done on humans.) Drug manufacturers recommend women stop taking weight loss drugs at least two months before a planned pregnancy.

“It’s true that, from a scientific perspective, these medications may make it easier for people to get pregnant,” said Dr. Allison Rodgers, an OB-GYN and reproductive endocrinologist at Fertility Centers of Illinois. “But people need to be careful because there could be dangerous consequences if taken while pregnant given the drugs can linger in your system.”

Why weight loss drugs may boost fertility

Decades of research have established strong connections between obesity, metabolic disorders such as polycystic ovary syndrome (PCOS) and fertility issues, so it isn't too surprising to see that weight loss medications — which can help some people drop up to 20% of their body weight — are helping many women with these conditions get pregnant, said Dr. Utsavi Shah, assistant professor of obstetrics and gynecology specializing in obesity medicine at Baylor College of Medicine in Houston.

“These weight loss medications are game changers for women with PCOS or infertility, but there’s nothing about them specifically that’s making people more fertile, aside from their interaction with birth control pills,” Shah said. “It’s their effect on weight loss that’s helping regulate their menstrual cycles, thereby increasing their chances of getting pregnant.”

Hayley Glatfelter, a 27-year-old from Texas, got pregnant in November four months after beginning semaglutide (the active ingredient in Ozempic). She started taking the drug to lose weight and treat her insulin resistance associated with PCOS — a hormonal disorder that causes weight gain, irregular menstrual periods, excess hair growth, and in some cases, fertility problems.

Although Glatfelter wasn’t on birth control, she said her positive pregnancy test was still surprising because she has had problems getting pregnant before, which is what led to her PCOS diagnosis in 2019. At that time, her doctor prescribed her a different diabetes drug called metformin, which is often used to help with PCOS-related insulin resistance. The drug helped Glatfelter get pregnant with her first son.

“I was told it was a miracle,” Glatfelter said.

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Fat cells release estrogen, so the more a person gains, the more estrogen they’ll have, Shah said. Excess estrogen can prevent regular menstruation and ovulation, which can make it hard to get pregnant.

Obesity causes insulin resistance as well, which can lead to high levels of male sex hormones like testosterone that don’t support pregnancy and affect egg quality, Shah said.

Some weight loss drugs can make your birth control pill less effective

Studies done in test tubes have found that tirzepatide — the active ingredient in Mounjaro and Zepbound — reduces the efficacy of oral contraception, aka the birth control pill, according to the drugs’ labels.

Mounjaro and Zepbound “delay gastric emptying,” meaning the stomach takes longer to clear out, which can affect how oral medications are absorbed in the body. The delay is largest after the first dose and diminishes over time.

Shah advises her patients taking these drugs and birth control pills to use a backup option, like condoms.

Semaglutide (Ozempic and WeGovy) doesn’t have as strong of an effect on gastric emptying, so its drug label doesn't contain warnings about oral contraceptives.

These drugs affect each person’s body differently, so risks vary, said Dr. Marina Kurian, a bariatric surgeon and president of the American Society for Metabolic & Bariatric Surgery.

“The birth control pill is still getting digested, the absorption rate may just be different in people, which would make its impact on the ovaries different too,” Kurian said.

That said, there’s always a small likelihood with any contraceptive that you can get pregnant, Shah said. But there’s no need to panic either.

“I know that there are stories out there that get escalated in the media, but if you're using effective birth control and on these weight loss medications, the risk of unintended pregnancy is quite low,” Shah said.

Only take weight loss medications if you meet criteria for its use, experts say. Zepbound and WeGovy, for example, are approved for weight management in adults who have obesity or are overweight with at least one weight-related condition, such as high blood pressure or Type 2 diabetes.

And if you suspect you’re pregnant while taking a weight loss drug, stop it immediately, Rodgers said, then follow up with your obstetrician.

This article originally appeared on USA TODAY: Can Ozempic make you fertile, pregnant? It's happening to some women.