Strokes are rare during a woman’s reproductive years but remain a serious threat, accounting for about 7% of deaths during pregnancy. A recent study published in JAMA Network Open explored the connection between infertility treatments and the risk of stroke in pregnant women.
As infertility rates climb worldwide, more women are undergoing treatments like intrauterine insemination and assisted reproductive technologies (ART). These procedures are generally considered safe, with few immediate complications. However, concerns persist about potential health risks during pregnancy and the postpartum period linked to these treatments.
Stroke ranks as the third leading cause of death in the United States. Nearly 20% of women face some stroke risk over their lifetime. Although the risk of fatal strokes, especially ischemic strokes, has dropped in recent decades, pregnancy introduces unique cardiovascular risks. In fact, cardiovascular issues cause over a quarter (27%) of pregnancy-related deaths. Researchers have long sought to understand if infertility treatments influence stroke risk, but prior studies have produced mixed results.
Some experts suspect that treatments like ovarian hyperstimulation may damage blood vessel linings and increase blood clotting, potentially raising stroke risk.
Study Design and Findings
This large study analyzed data from the Nationwide Readmissions Database, covering hospitalizations in 28 U.S. states. Researchers examined records from more than 31 million women aged 15 to 54 who gave birth between 2010 and 2018. They compared women who received infertility treatment before pregnancy with those who conceived naturally. All women had been hospitalized for any reason within the same year following delivery.
Infertility treatments considered included intrauterine insemination, ART, fertility preservation, and surrogacy. Only nonfatal strokes requiring hospitalization were counted.
Fewer than 1% of women in the study had undergone infertility treatment before conceiving. Among these, 105 hospitalizations for stroke were recorded, compared to over 9,000 stroke cases in the natural conception group. This translated to stroke rates of 37 per 100,000 women with infertility treatment versus 29 per 100,000 without.
The risk of stroke hospitalization in the year after delivery was 66% higher for women who had infertility treatment. Hemorrhagic strokes (bleeding strokes) showed the largest increase, with a risk twice as high. Ischemic strokes (caused by blood clots) also rose by about 50%. After adjusting for other risk factors, the association grew stronger for hemorrhagic strokes but weakened for ischemic strokes.
The increased stroke risk appeared from 30 days postpartum and persisted through the year following childbirth.
Possible Explanations for Increased Stroke Risk
Previous studies sometimes found infertility treatment linked to lower cardiovascular risk, but differences in populations and methods may explain conflicting results.
One theory is that older women, who naturally face higher cardiovascular risks, are more likely to undergo ART, making it harder to separate the effects of age and treatment.
Infertility treatments have also been connected to pregnancy complications such as placental abruption, fetal growth restriction, pre-eclampsia, kidney disorders, and diabetes—all of which can increase stroke and cardiovascular disease risk.
Another explanation involves the biological effects of infertility treatments themselves. Hormonal medications may damage blood vessel linings or create a pro-clotting environment. Combined with natural changes in blood circulation during pregnancy, these effects could raise stroke risk.
Additionally, some women undergoing infertility treatment may have existing risk factors like obesity, smoking, or alcohol use that amplify their risk during pregnancy.
Currently, older women are advised to have cardiovascular screening before starting ART. However, the study authors suggest that all women should undergo such screening to identify those at risk for stroke before infertility treatment begins.
Implications for Care and Future Research
The study highlights the need for careful monitoring of women receiving infertility treatments. These women face a significantly higher chance of stroke hospitalization, especially for hemorrhagic stroke, in the first year after childbirth.
However, the study did not adjust for important factors such as diabetes, hypertensive disorders during pregnancy, or pre-existing vascular conditions like fetal growth restriction or stillbirth. These could influence the risk and should be included in future research.
Ethnicity and treatment protocols for pregnancy complications might also affect stroke risk and need further study.
The American College of Obstetricians and Gynecologists (ACOG) currently recommends postpartum check-ups at 3 weeks and 12 weeks after delivery, with earlier visits if pregnancy complications occurred. Given the findings, there may be a need for even closer follow-up and targeted stroke risk screening in women who have had infertility treatments.
Conclusion
This study underscores a critical health concern: infertility treatments may increase the risk of stroke hospitalization in the year after childbirth, particularly hemorrhagic strokes. Better screening and timely postpartum care could help identify women at risk and reduce stroke incidence. As infertility treatments become more common, healthcare providers must be aware of these risks and tailor care accordingly.
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