Aortic Stenosis and Pregnancy

Aortic stenosis, a narrowing or stiffening of the aortic valve, creates resistance to blood flow out of the left ventricle. The result is a potential for backup on the left side of your heart. It can be acquired due to rheumatic fever, but it may also be congenital.

What This Means for Your Pregnancy

Pregnant women with only mild to moderate stenosis often are without symptoms and do quite well. If, however, your stenosis is severe enough to cause a significant narrowing of the aortic valve, the result can be a very inefficient heart. Anytime cardiac output is compromised, both you and your baby are at risk for decreased blood flow to your vital organs, including your brain, heart, and uterus.

In moderate to severe disease, symptoms may occur even with minimal exertion. These include chest pain, fainting, irregular or rapid heart beats, heart failure, and sometimes sudden cardiac death. The greatest risk is at the time of delivery when sudden, rapid shifts in fluid volume occur requiring your cardiac system to adapt, and it is sometimes difficult for your body to handle these adaptive changes.

Implications for the Baby

There is some risk that your child may develop a cardiac problem because this problem is most commonly congenital and may be inherited. Additionally, in cases of severe disease, if there is a decrease in good blood flow to the uterus during important times of fetal development, overall organ system development may be adversely affected, including your baby's heart. Later in gestation, your baby continues to be at risk for poor growth due to a decrease in blood flow through your uterus.

Decisions regarding the care management and monitoring you and your baby's status will involve the primary OB/Gyn, the perinatologist, the cardiologist, and in cases of anticipated early delivery, the neonatologist.

Anticipated Management and Care

If you are without symptoms, only close monitoring of both you and your baby is necessary. However, in cases where significant symptoms (as those previously described) are present, physical activity is strictly limited to maximize adequate blood flow. Additionally, close monitoring for any infection is necessary, including prompt recognition and treatment.

It is important to know that if symptoms persist, even with strict bedrest, surgical intervention may be necessary. If your heart condition worsens early in your pregnancy, your care provider may suggest that you terminate your pregnancy to ensure your safety. However, many of the severe symptoms often do not develop until later in pregnancy. In these cases, valve replacement or surgical enlargement of the existing valve (called valvotomy) can be done. Another option, depending on the severity of disease, may be the use of a balloon catheter. This device is threaded through a large blood vessel, into the aortic valve itself, and the balloon on the end of the catheter is inflated to enlarge the opening.

Labor and delivery are often the time of greatest risk, particularly if stenosis of the aortic valve is severe. In these instances, it is necessary for you and your baby to be closely monitored throughout labor and delivery, as well as immediately postpartum. During labor, you can expect to have intravenous fluids; antibiotics; close monitoring of your baby's heart rate and your contractions; a specialized intravenous line (called a Swan-Ganz catheter) that can monitor fluid volume, pressures, and cardiac output; pain relief with intravenous narcotic administration or epidural narcotics; and avoidance of actually pushing during delivery by use of forceps instead. Additionally, the time immediately after birth is critical and requires close monitoring of total blood volume and pressures to avoid a significant drop in blood pressure or an overload of fluid. In circumstances of even moderate blood loss, it might be necessary to replace what blood was lost. Management of complex cases will require the collaborative work of you and your family, your primary OB/Gyn, the perinatologist, the cardiologist, and the neonatologist, who may need to make decisions regarding delivery prior to the due date. In sick pregnant women, decisions are often made by weighing the risks and benefits to both mother and baby. Does the benefit of keeping baby inside a little longer outweigh the risk to mom? Many variables play into these difficult decisions. If early delivery is anticipated, the physicians may suggest giving you steroid injections to help prepare the baby's lungs for a preterm delivery.