September 01, 2023
Women who became pregnant after being treated for infertility were more likely to have a stroke within the first year after giving birth compared to those who conceived naturally, but their overall risk remained low, according to new research.
Researchers found women that received treatments like intrauterine insemination, in vitro fertilization, surrogacy and egg freezing had an elevated stroke risk within the first 30 days after delivery. That risk continued to rise throughout the year.
Still, the study found their overall risk of stroke remained low. There were just 37 stroke hospitalizations for every 100,000 women who received infertility treatment. For women who conceived naturally, the rate was 29 stroke hospitalizations per 100,000 women.
Overall, women who underwent infertility treatment were 66% more likely to be hospitalized with a stroke. Their risk of being hospitalized by a hemorrhagic stroke – caused by bleeding in the brain – was nearly twice as high. Their risk of ischemic stroke – caused by a blood clot in the brain – was 55% higher.
The study, published by the Journal of the American Medical Association, analyzed more than 31 million people who delivered babies between 2010 and 2018, including 287,813 people who underwent infertility treatments. It is the largest study to assess the risk of postpartum stroke among people who have been treated for infertility.
Dr. Cande V. Ananth, chief of epidemiology and biostatistics at the Robert Wood Johnson Medical School, told the New York Times that stroke remains rare after childbirth, regardless of whether someone has been treated for infertility.
Dr. Sahar Wertheimer, a reproductive endocrinologist at HRC Fertility in California, echoed that opinion in an interview with Medical News Today.
"People should be aware of the increased risks of IVF in general, including the slightly higher risks posed to the pregnancy," Wertheimer said. "But everything in medicine is risk versus benefit. Fertility treatments allow couples with infertility to have the most amazing, life-changing results."
About 12.7% of women of reproductive age seek treatment for infertility each year, and about 2% of all live births in the U.S. involve some method of infertility treatment, research shows. Though infertility treatments are considered generally safe, some studies have linked them to an increased risk of preeclampsia, which can be deadly.
Research also has linked infertility treatments to increased risk of vascular issues like irregular heartbeat and kidney injury as well as pregnancy complications like placental separation, preterm birth or cesarean delivery.
The latest study outlined several explanations for the increased stroke risk among people who received infertility treatments.
Health issues previously linked to infertility treatments, like preeclampsia and kidney disorders, can increase stroke risk. Additionally, changes in heart rate and blood pressure during infertility treatments may increase risk, though that remains unclear. People receiving infertility treatments also may have other health factors – obesity, smoking and alcohol use – that increase the risk of stroke, and pregnancy may unmask those shared risk factors.
Researchers said future studies are needed to evaluate the stroke risks associated with infertility treatments and the need for additional follow-up appointments among postpartum mothers who are already at a higher risk for stroke.