Weight Has Long Been A Barrier To IVF. Ozempic Could Change That.

Diana Zucknick was diagnosed with polycystic ovary syndrome (PCOS) when she was a teenager, so she and her husband knew they might need help getting pregnant. Their first visit to an Austin-area fertility clinic yielded surprising news: Her husband had a low sperm count and the few he had were genetically abnormal, so he would need surgery to improve his semen parameters before they could start treatments.

After surgery and a year of visits to urologists, they were ready to try again, but this time, a new surprise lay in store. Zucknick, then 29, completed a number of preliminary examinations, such as checking her fallopian tubes to make sure they weren’t blocked, and was preparing to begin the hormonal stimulation that is the first step in an egg retrieval for in vitro fertilization (IVF). At the end of the appointment, she was asked to step on a scale.

“Nobody told me to my face that the number that I read out to them was a problem,” she said. “I got a phone call later. And that’s when they told me they weren’t going to move forward with an egg retrieval with me because my BMI [body mass index] was too high.”

At the time, she was between 340 and 350 pounds, but had been told she “wore her weight well” on her 5-foot-5-inch frame. She knew she was overweight but generally felt healthy. To get to the BMI the clinic required, she’d have to lose 100 pounds, nearly a third of her body weight. Zucknick was devastated. She eventually worked up the courage to call a few more clinics in the Austin area.

“There was no clinic anywhere around me in Texas that would work with somebody of my size,” she said. Some of the clinics told her it was because of “anesthesia,” but it was never spelled out to her in any more detail than that.

Zucknick is not alone in facing this problem. Nationwide, fertility clinics not housed within hospitals are typically only accredited to perform anesthesia on patients classified by the American Society of Anesthesiologists as having a risk score of I, “a normal healthy patient,” or II, “a patient with mild systemic disease.” A patient with a BMI over 40 is considered “morbidly obese,” which carries a risk score of III, putting them outside of the clinic’s anesthesia accreditation.

“Nobody really explained it exactly, and I wasn’t entirely sure why I was turned away,” Zucknick said. “I just knew that my goal was to lose weight.”

Although there is no BMI cutoff for men, she and her husband both committed to losing weight. She changed her diet, cutting back on her beloved Mexican food, and trained for a half marathon. Zucknick worked as a teacher at the time, and watched over the years as one after another of her mostly female colleagues became pregnant. Despite her best efforts, she could never keep her weight below 300 pounds, and eventually developed Type 2 diabetes. In 2021 — 11 years after that first fertility clinic visit — she and her primary care practitioner were discussing putting her on insulin when he mentioned he’d had a lot of success treating diabetic patients with a new class of weekly injectable drugs that help control blood sugar. Zucknick started on Ozempic in the summer of 2021, and the weight “melted away,” she said. By January 2022, at age 39, she had lost enough to begin reaching out to local IVF doctors again.

This family of drugs, developed to combat diabetes, has exploded in popularity with people who have long struggled to lose weight through traditional means such as diet and exercise. They are known as GLP-1 agonists because they mimic the action of the hormone glucagon-like peptide 1, which helps control blood sugar. They have also been shown to slow the emptying of the stomach. Zucknick, like many other patients, said the “food noise” that often filled her thoughts finally disappeared. “I felt like, for the first time ever, I knew what silence felt like, because I had never not thought about my next meal,” she said.

“They told me they weren’t going to move forward with an egg retrieval with me because my BMI was too high.”

Most importantly for Zucknick, and other patients who’ve been turned away from fertility clinics because of their weight, Ozempic put her back on the path to potential parenthood. For patients who’ve been turned away from fertility care based on their BMI, these drugs may put treatment within reach again. But like many new drugs, their effect on people trying to conceive, pregnant patients, or their children is not yet fully known. By using them, Zucknick and others like her may be able to attempt getting pregnant again, but at what cost?

Novo Nordisk, the Danish drugmaker that manufactures three of the most popular formulations — Ozempic, Rybelsus, and Wegovy — is conducting a pregnancy registry for Wevogy (the only one of the three approved for use specifically in weight loss), in which it will compare pregnancy outcomes for people exposed to Wegovy during pregnancy, and overweight and obese people who were not exposed during pregnancy. The company estimates it will enroll over 1,100 patients, but public results from this study are not due to be reported until after it concludes in August 2027.

In the meantime, Novo Nordisk advises stopping Wegovy at least two months before a planned pregnancy to allow for what is known as a “washout period” — the recommended length of time it takes for a given drug to clear a patient’s body. “Individual patient decisions should be made together with a health care provider, as part of a shared decision-making process,” the company said in a statement.

For now, we know a few things: Obesity itself is linked to lower likelihood of IVF success and a range of pregnancy complications such as miscarriage and preeclampsia. A high BMI during pregnancy can also adversely affect the fetus, potentially causing congenital disorders, or childhood asthma or obesity. We also know that overweight people can and do get pregnant and have healthy children. Furthermore, we know that studies conducted for all three medications showed birth defects and higher rates of miscarriage in rats, rabbits, and monkeys, as well as increased pregnancy loss in the latter two animals, although it is not clear whether this was because of the drugs themselves or the animals’ rapid weight loss. For this reason, some doctors err on the side of caution, advising cessation of the medications well in advance of an egg retrieval, up to two or three months. Other providers believe the benefits of pursuing fertility treatment at a lower weight exceed the potential harms that could result. In the absence of hard data, patients are receiving a wide range of advice from their care providers.

Many patients are not at their ideal BMI when they first arrive at the IVF clinic, said Dr. Alex Robles, a fertility specialist at New York’s Columbia University Fertility Center. For younger patients, he will often suggest lifestyle changes such as diet and exercise at the initial consultation, because those patients have time to lose weight before starting treatment. However, for older patients, when time is of the essence, semaglutides like Ozempic could play a role in aiding weight loss and normalizing metabolic activity. In those cases, he might suggest a patient work with their primary care physician or medical endocrinologist who can monitor their semaglutide use, since the drugs require close follow-up.

Because so little is known about semaglutides and their sister drugs, liraglutides, which are typically injected daily, doctors are left speculating about the ways in which they could theoretically help — or possibly hurt — a patient’s chance of getting pregnant. Robles thinks they could impact an IVF cycle in several different ways. At the heart of the female reproductive process is a complex hormonal feedback loop called the hypothalamic-pituitary-ovarian (HPO) axis, the system by which the brain and the ovaries talk to each other. The HPO axis controls the ovulatory cycle and can be disrupted by any number of endocrine disorders, such as PCOS (which affects between 6 and 10% of reproductive-aged women) or by obesity (which affects about 31%).

“By getting closer to your ideal body mass index, that can actually help restore that HPO axis,” Robles said. On the other hand, he said, rapid weight loss can slow functioning of the pituitary gland, which secretes the hormones FSH and LH, the same ones that are stimulated through hormone injections during an IVF cycle. “If there is any potential interruption of your pituitary sensitivity, meaning that it’s not producing hormones like it normally would, that would render some of the medications that we use in the fertility realm ineffective,” he added.

It is possible that since weight loss can reduce inflammation, losing weight at a measured pace on semaglutides will help facilitate pregnancy. But it is also difficult to know whether that factor would be outweighed by the drugs’ possible side effects, said Dr. Carolyn Alexander, a fertility specialist at Southern California Reproductive Center in Los Angeles. One small study of 28 patients with PCOS and obesity found that women assigned a low-dose liraglutide before IVF in addition to the commonly prescribed diabetes drug metformin had higher pregnancy rates than women treated with metformin alone. But GLP-1 receptor agonists could potentially affect the granulosa cells in the follicle around the egg, which provide nutrition for the egg and secrete hormones that help regulate the follicle’s growth and maturation. Theoretically, they might also interfere with GLP-1 receptors on the ovary or endometrium, but it is unclear what the effects of this influence on the egg’s microenvironment would be.

The drugs’ known side effects can also create potential hazards. Because they appear to slow the emptying of the stomach, there is a risk that a patient might accidentally draw food into the airway passage while under anesthesia, Robles said. There’s also the chance that a patient’s electrolytes could be depleted due to vomiting and diarrhea, commonly reported complaints among semaglutide patients, said Dr. Nicole Noyes, a longtime fertility specialist in New York. She also worries about the psychological effect of gaining significant amounts of weight during pregnancy on patients who have been working hard to lose weight. “I’m sure that’s very difficult to think about, when you’re taking a medication this strong to lose the weight, to know you’re going to gain weight with a pregnancy and not be able to take the medication,” said Noyes.

While some patients lose weight to meet a clinic’s guidelines or because they or their medical providers believe it will help them get pregnant, others turn to semaglutides just to meet the medical profession’s expectations of an ideal patient. After Sarah (not her real name), a fertility patient in the Illinois suburbs, gave birth to her second child at 35 weeks, a maternal-fetal medicine (MFM) specialist attributed the premature delivery to her weight, and warned her she “shouldn’t have another baby” until she returned to her pre-pregnancy weight of 180 pounds. Sarah, 38, and her husband hope to have four kids in all.

“I’m sure that’s very difficult to think about, when you’re taking a medication this strong to lose the weight, to know you’re going to gain weight with a pregnancy and not be able to take the medication.”

Although her fertility doctor was not concerned about her weight, Sarah went on Saxenda (a daily injectable weight loss drug) under the guidance of her endocrinologist, who had previously treated her with metformin and insulin to control her PCOS and gestational diabetes. Sarah and her two doctors tried to balance the endocrinologist’s concerns about the drug’s safety during pregnancy with Sarah’s urge to lose weight in order to meet the MFM’s textbook criteria of how much she should weigh for her next pregnancy.

“I wanted to get back to the pre-pregnancy weight because I still kind of believed that the MFM was right,” she said. “That was kind of the back and forth — it was about me wanting to continue the med because I felt like it was helping me lose weight, and [the endocrinologist] saying, ‘I want to do this as safely as possible,’” she said.

After getting down to about 5 pounds over her pre-pregnancy weight, she went off Saxenda, gaining about 10 pounds over four months. She had two failed frozen embryo transfers before going back to her endocrinologist in July of last year, walking out with a prescription for Ozempic. She took it from July until early September, going off before her next embryo transfer in October. This time, the transfer was successful; she gave birth to her third baby in June. Sarah is not sure whether the weight loss contributed to her getting pregnant, but she is certain that the pressure to lose weight is “related to fatphobia in medicine” on the part of the MFM, since her BMI was just 31 when she began Ozempic.

“Apparently my risks were exponentially higher than if my BMI was 29,” she said sarcastically. “No one forced me to take Ozempic,” she added, noting that even her endocrinologist seemed more concerned with obesity as a public health issue than specific risks to Sarah’s pregnancy due to her weight. “I asked my endocrinologist and she agreed because ‘obesity is an epidemic.’”

Indeed, the fact that many doctors will work with patients who are technically obese — and successfully get them pregnant — suggests that weight may be a far less important variable than, for example, age. For Zucknick, that now seems to be the key factor. By the time she and her husband finally found a doctor in New York who would work with them, she was already 39, when the chances of a live birth from an IVF cycle fall to about 20%, compared with a 40% success rate for patients under 35. When she woke up from her first egg retrieval, instead of being excited that her doctor had retrieved 13 eggs, she was devastated — she hadn’t realized that the retrieval is typically done with a needle inserted into the vagina, rather than through the abdomen.

“For almost 10 years, that was my assumption — that the reason why they never went forward with an egg retrieval with me was because I had too much literal body fat,” she said. “I had not understood that they extract them from the inside.” (Doctors sometimes retrieve eggs guided by a transabdominal ultrasound for obese patients whose ovaries are not accessible vaginally, because having too much fat around the vagina can complicate the extraction procedure.) It pains her to think about it, but perhaps if she had known, she could have started IVF years ago had she found the right doctor.

Their first embryo transfer failed. The second one took, but she eventually miscarried. They’ve also been able to do two rounds of IVF locally since she met the BMI limit, but none have been successful. She is now on Mounjaro and has undergone six egg retrieval cycles at an Austin clinic since August, while her husband recovers from a second varicocele removal surgery. They plan to bank as many eggs as possible over a total of eight cycles, and then attempt one last round of IVF in the spring, once he has healed.

“For almost 10 years, that was my assumption — that the reason why they never went forward with an egg retrieval with me was because I had too much literal body fat.”

“What we don’t know currently is how much of this is due to age-related egg quality, and how much of it is due to our sperm deficiencies,” she said. “I can’t know for sure, because I don’t have a time machine, but I do know that my eggs at 29 years old would have likely performed better than my eggs now at 40.”

Zucknick encourages anyone being turned away from a clinic to seek out a provider who will examine their case individually and holistically. When trying to have a baby, weight is just one factor among many — age, especially for women, may be even more important. “I think it’s really important for people to know that putting this off in order to lose weight is not the right choice,” Zucknick said. “If they’re going to continue to use anesthesia as the excuse to, you know, to basically keep somebody from this care — that’s just bullsh*t. Fat people have surgeries all the time.”

If you or someone you know has an eating disorder and needs help, call 988 or text “NEDA” to 741741 to be connected with a trained volunteer at Crisis Text Line. Another resource is the Alliance for Eating Disorders.

Anna Louie Sussman is a New York-based journalist with extensive experience reporting on gender, economics, health, and reproduction. She is currently at work on the book,“Inconceivable: Reproduction in an Age of Uncertainty,” which looks at the challenges people face in starting and growing their families.