Outcomes and Long-term Effects of Pregnancy in Women With Biologic and Mechanical Valve Prostheses

Abstract

The optimal choice of prosthetic heart valve for women of child-bearing age is not well established. We conducted this retrospective cohort study to compare pregnancy outcomes and maternal mortality and morbidity, including long-term valve reoperation, between women with biologic and mechanical valve replacements. Women ≤50 years of age with prosthetic heart valve implantation and subsequent pregnancy in California, New Jersey, and New York State between 1990 to 2015 were identified using mandatory state inpatient databases. Average follow-up time was 9.4 years (SD 6.7 years). Of 11,930 women who underwent 14,017 valve replacements, pregnancies in 417 women with 241 biologic valves, and 217 mechanical valves were identified. Women with mechanical prostheses experienced significantly higher rates of pregnancy loss, with almost 2/3 of pregnancies ending in either spontaneous or induced abortion, and hemorrhage and thromboembolic events during delivery. Delivery was a significant risk factor for reoperation for both biologic (hazard ratio 2.5, 95% confidence interval 1.6 to 3.8 after time-dependent propensity matching) and mechanical (hazard ratio 2.3, 95% confidence interval 1.3 to 4.1 after time-dependent propensity matching) prostheses. Half of reoperations in women with mechanical valves who experienced pregnancy occurred within 1 year after delivery, and most were associated with mitral valve thrombosis. In conclusion, pregnancy accelerates time to reoperation for both biologic and mechanical prostheses. Mechanical valves are at particular risk for near-term valve failure after delivery, and compared with bioprostheses, are associated with higher rates of adverse events during pregnancy.