Biological heart valves support safer pregnancies despite reoperation risks

In severe disease of the aortic valve, choosing a new heart valve is especially difficult for young women who want to become pregnant. A new Swedish registry study from Karolinska Institutet shows that a biological aortic valve leads to good pregnancy and delivery outcomes, even though the need for another operation is more common than with a mechanical valve. The study is published in the Journal of the American College of Cardiology (JACC).

In serious aortic valve disease, surgery to replace the valve may be necessary, even in young women. There are mainly two options. Mechanical valves are very durable but require lifelong treatment with blood-thinning medications, which can pose risks for both the woman and the fetus during pregnancy. Biological valves, on the other hand, do not require the same type of blood thinners, but they wear out faster and may lead to the need for another operation later in life.

In the current study, researchers analyzed women in Sweden aged 18-40 who had undergone aortic valve replacement between 1997 and 2024. A total of 251 women were included, of whom 93 received a biological valve and 158 a mechanical valve. The data were taken from national registries and followed over a long period.

Help provide better information for joint decisions

About half of the women who received a biological valve had at least one child during the follow-up period, compared with fewer than one in ten of those who received a mechanical valve. For women with a biological valve, the long-term cardiovascular outcomes were favorable despite high reintervention rates.

Our results show that a biological valve is a reasonable option for women planning pregnancy, even though one must be aware of the risk of future reoperation. We hope the results can support better shared decision-making between doctors and patients.”

Ruixin Lu, PhD student, Department of Molecular Medicine and Surgery at Karolinska Institutet

“It is encouraging that many women with a biological aortic valve can go through pregnancy and childbirth. At the same time, we know that many of these young women will later need another operation, because the valve wears out over time. In our continued research, we are investigating how assessment and treatment can be improved ahead of their next heart operation”, says Ulrik Sartipy, cardiac surgeon at Karolinska University Hospital and adjunct professor at the Department of Molecular Medicine and Surgery at Karolinska Institutet.

The researchers emphasize that the choice of valve must always be tailored to the individual patient’s situation and life plans.

The study is a national observational study based on Swedish health data registries. It was conducted in collaboration between Karolinska Institutet and Karolinska University Hospital. Funding came from sources including the Swedish Heart-Lung Foundation, Region Stockholm, and foundations linked to Karolinska Institutet.