Valvular heart disease and pregnancy:
follow-up, risks and planning

Article written and reviewed by Dr Luca Moretti

Many women with valvular heart disease can undergo pregnancy, but the risk varies greatly from one situation to another. Mild, well-compensated forms are often tolerated, whereas severe stenosis, ventricular dysfunction, pulmonary hypertension or a mechanical prosthesis may require highly specialized management.
The period before conception is often the most useful time to reduce risks.

The 2025 ESC guidelines recommend pre-pregnancy assessment in women with known heart disease and, in higher-risk cases, involvement of a Pregnancy Heart Team bringing together cardiology, obstetrics and other necessary expertise. The aim is to determine whether the valve can tolerate the increase in blood volume and cardiac output during pregnancy and whether treatment is needed before pregnancy begins.

What should be checked before trying to become pregnant

Before conception, symptoms, severity of valvular heart disease, ventricular dimensions and function, pulmonary pressure, heart rhythm and therapy are assessed. The echocardiogram is the key examination; in some conditions an exercise test may be useful to assess functional capacity when the woman appears asymptomatic.
In bicuspid aortic valve disease, the aorta must also be measured carefully because significant dilation changes pregnancy management.

If there is already a strong indication for a valve intervention, it is generally preferable to address it before pregnancy. Preventive intervention for a simple, well-tolerated regurgitant lesion is not recommended solely because pregnancy is desired when the usual indications for treatment are absent.

Why stenosis can cause more problems than regurgitation

During pregnancy, the amount of blood the heart must pump increases. In the presence of stenosis, increased flow through a narrowed orifice raises the gradient and can make a previously well-compensated condition symptomatic.
Significant mitral stenosis can promote pulmonary congestion, dyspnea and arrhythmias; the risk increases with severity.

Aortic stenosis also requires careful assessment. A woman with severe stenosis but normal exercise tolerance may have a different course from a woman who is already symptomatic before pregnancy.
Aortic and mitral regurgitation are often better tolerated because the reduction in vascular resistance during pregnancy may lessen the regurgitant load, but risk increases when ventricular dysfunction, pulmonary hypertension or previous cardiac events are present.

Prosthetic valves and pregnancy: why a mechanical valve requires greater attention

A well-functioning bioprosthesis is generally simpler to manage during pregnancy than a mechanical prosthesis. The 2025 ESC guidelines therefore recommend preferring, when appropriate, a biological prosthesis over a mechanical one in young women who anticipate pregnancy and require valve replacement.
A bioprosthesis, however, has limited durability and may degenerate earlier in younger people, so the choice must still consider the patient’s entire lifetime.

Pregnancy with a mechanical prosthesis is considered high risk because the valve requires continuous and effective anticoagulation. In the international ROPAC III registry, a pregnancy without major complications resulting in a live birth occurred in 54% of women with a mechanical valve compared with 79% of those with a biological valve.
These numbers describe groups of patients and do not by themselves predict the outcome of an individual pregnancy, but they explain why planning is essential.

Anticoagulation with a mechanical valve: what not to do on your own

Vitamin K antagonists protect the mother very effectively against prosthetic valve thrombosis, but they cross the placenta and can cause fetal problems. Low-molecular-weight heparins do not cross the placenta, but in mechanical valves they require therapeutic doses and specific monitoring of anti-Xa activity; inadequate treatment increases the risk of valve thrombosis.
There is therefore no simple substitution that can be made independently as soon as a pregnancy test becomes positive.

The 2025 ESC guidelines provide different strategies according to the dose of vitamin K antagonist required, the trimester, thrombosis risk and the ability to monitor heparin correctly. In the second and third trimesters, vitamin K antagonists often remain the favored strategy to protect the mother, especially in high-risk profiles; close to delivery, therapy must be changed in a planned manner.
A woman with a mechanical prosthesis who discovers that she is pregnant should therefore contact the treating team immediately without stopping the anticoagulant on her own.

How follow-up and delivery are organized

The frequency of follow-up depends on risk. In more significant lesions, repeated echocardiograms during pregnancy may be needed to monitor gradients, ventricular function and pulmonary pressure.
In women with mechanical prostheses, guidelines recommend regular echocardiographic follow-up, generally at least once per trimester if the condition is stable, in addition to very close monitoring of anticoagulation.

The mode of delivery does not depend only on the valve diagnosis. In many women with stable heart disease, vaginal delivery is possible; cesarean delivery is chosen when there is a specific cardiac indication, an obstetric indication or a reason related to anticoagulation management.
For mechanical prostheses, the delivery plan must include in advance how and when to stop the vitamin K antagonist, how to use heparin and when to restart therapy after delivery.

The period immediately after birth remains important because rapid changes in circulating volumes can worsen heart disease. Follow-up therefore does not end with delivery.

Frequently asked questions about valvular heart disease and pregnancy

Can you have a pregnancy with valvular heart disease?
Very often, yes, but risk should be assessed before conception according to the lesion and cardiac function.

Which valve diseases are more difficult to tolerate?
Significant stenotic lesions, particularly mitral and aortic stenosis, are generally more problematic than well-compensated regurgitation.

Can you have a pregnancy with a mechanical valve?
It is possible, but it is a high-risk pregnancy, especially because of anticoagulation management, and requires a Pregnancy Heart Team.

Can I stop warfarin as soon as the test is positive?
No. Unplanned interruption can cause valve thrombosis. The treating team should be contacted immediately.

Does delivery always have to be by cesarean section?
No. Vaginal delivery is possible in many situations; the mode and timing are planned according to cardiac risk, anticoagulation and obstetric indications.