Infertility treatment may increase stroke hospitalization risk within 1 year of delivery

Key takeaways:

• Within 12 months of childbirth, stroke hospitalization rates were 37 per 100,000 people for women who received infertility treatment.
• Hemorrhagic stroke hospitalization risk was greater than ischemic stroke hospitalization risk.

Within 12 months after childbirth, women who underwent infertility treatment had an increased risk for stroke-related hospitalization, according to a large population-based, retrospective cohort study published in JAMA Network Open.

One theory for the association between infertility treatment and stroke risk is that the increased risk for hypertension and gestational diabetes in women undergoing fertility treatment may also increase stroke risk, the researchers noted. In addition, the researchers highlighted that other theories for the association include direct endothelial cell damage after infertility treatment and the release of prothrombotic factors after ovarian hyperstimulation due to estrogen doses required for IVF.

“Given these potential reasons why infertility treatment may be associated with stroke risk, we hypothesized that treatment for infertility is associated with an increased risk of both hemorrhagic and ischemic stroke,” Devika Sachdev, MD, resident in the department of obstetrics, gynecology and reproductive sciences at Rutgers Robert Wood Johnson Medical School in New Brunswick, New Jersey, and colleagues wrote.

Sachdev and colleagues evaluated data from 31,339,991 women obtained from the Nationwide Readmissions Database from 28 U.S. states from 2010 to 2018. All women had a hospital delivery from January to November each calendar year as well as subsequent hospitalizations in the same calendar year of delivery during the study period. Researchers evaluated hospital childbirth following spontaneous conception or infertility treatment including intrauterine insemination, assisted reproductive technology, fertility preservation procedures or use of a gestational carrier.

The primary outcome was hospitalization for nonfatal stroke within the first 12 months after childbirth. Secondary outcomes included risk for stroke hospitalization less than 30 days, less than 60 days, less than 90 days and less than 180 days postpartum.

Overall, 0.9% of women (median age, 32.1 years) included in this study underwent infertility treatment. Stroke hospitalization rate within 12 months of childbirth was 37 hospitalizations per 100,000 people among women who underwent fertility treatment and 29 hospitalizations per 100,000 people among women who delivered following spontaneous conception (adjusted HR = 1.66; 95% CI, 1.17-2.35).

Hemorrhagic stroke hospitalization risk (aHR = 2.02; 95% CI, 1.13-3.61) was greater than ischemic stroke hospitalization risk (aHR = 1.55; 95% CI, 1.01-2.39) among women who received infertility treatment.

Researchers noted that as time between childbirth and stroke hospitalizations increased, so did the risk for stroke hospitalization, especially for hemorrhagic strokes. These associations grew larger for hemorrhagic stroke and were similar for ischemic stroke after correcting for biases.

“Further exploration into this association is warranted and efforts should be made to mitigate all factors associated with increased risk of stroke and other CVD in the antenatal and postpartum periods,” the researchers wrote.