Long-term cardiovascular risk in women prescribed fertility therapy

Objective — The authors investigated whether fertility therapy might contribute to subsequent cardiovascular disease.

Background — Fertility medications are used for one percent of births yet may also lead to endothelial injury with long-term adverse consequence for the mother.

Methods — The authors performed a population-based cohort analysis of women who gave birth in Ontario, Canada between July 1, 1993 and March 31, 2010, distinguishing those who did and did not receive fertility therapy in the two years prior to delivery. Cox proportional models were derived to estimate hazard ratios (HR) with and without adjustment for baseline characteristics. The primary outcome was a composite cardiovascular endpoint of death, non-fatal coronary ischemia, stroke, transient ischemic attack, thromboembolism or heart failure.

Results — Among 1,186,753 women who delivered during the study period, 6,979 gave birth following fertility therapy. After 9.7 years of median follow-up, women who delivered following fertility therapy had fewer cardiovascular events than controls (103 vs. 117 events per 100,000 person-years), equivalent to an unadjusted HR 0.96 (95% confidence interval [CI], 0.72-1.29, p=0.79) and an adjusted HR 0.55 (95% CI, 0.41-0.74, p<0.0001). An apparent relative lower risk was observed across all age and income groups. Women who received fertility therapy also had lower risk-adjusted all-cause mortality, thromboembolic events, subsequent depression, alcoholism, and self-harm (p<0.01 for each).

Conclusion — Successful fertility therapy was not associated with an increased risk of cardiovascular disease later in life.