Does a History of Preeclampsia Impact Hormonal Therapy?

I am 39 and starting to notice hormonal changes. After having preeclampsia with both my pregnancies, I was told that I needed a form of birth control without estrogen, as estrogen introduces additional risks to people with a history of high blood pressure. (I now have the Mirena IUD.) Does that mean hormone replacement options are also not available to me? My blood pressure is currently normal without medication.

—Anonymous

Thinking about how estrogen and cardiovascular risk are connected is tricky. Premenopausal women are relatively protected from cardiovascular risk by estrogen. However, we also know that in some conditions, combination hormone therapy containing estrogen and progesterone may increase the risk for cardiovascular disease. Preeclampsia is a risk factor for developing cardiovascular risk in the future, but a history of preeclampsia is not an absolute contraindication to taking estrogen.

Historically we thought that hormone therapy would reduce a woman’s risk for cardiovascular disease. In fact, one of the goals of the Women’s Health Initiative was to demonstrate that combination hormone therapy reduces cardiovascular risk in postmenopausal women. Instead, rates of cardiovascular disease were increased in women taking estrogen and progesterone.

Since the publication of the WHI study 20 years ago, we have learned about the importance of when hormone therapy is given. There is some evidence that hormone therapy, and in particular estrogen, given within 10 years of menopause and via patch or gel may reduce cardiovascular risk.

The guidelines recommend calculating a woman’s risk for developing cardiovascular disease to determine whether hormone therapy poses an increased risk to that particular patient based on this calculator. If a patient has less than a 5% risk of a cardiovascular event in the next 10 years, hormone therapy is considered safe. If the patient has a 5% to 10% risk, it is recommended that they use only transdermal estrogen. If a patient has a greater than 10% risk of a cardiovascular event in the next 10 years, the guidelines recommend non-hormonal options for managing the symptoms of menopause.

A history of preeclampsia or high blood pressure in the past is not a risk factor included in the calculator. Current high blood pressure is included. If a woman had a history of preeclampsia and no other risk factors for cardiovascular disease (risk factors other than current hypertension included in the calculator are high cholesterol, diabetes, and smoking cigarettes), under the current guidelines she would be eligible for hormone therapy.

It is also important to remember that guidelines are just that: a guide. They are not hard-and-fast rules. Rather, you and your doctor should consider whether you have perimenopausal symptoms that might be treated with hormone therapy and what your risk for having a cardiovascular event is to determine whether the benefits of hormone therapy outweigh the risks for you.

Ultimately, a history of preeclampsia doesn’t mean you shouldn’t take estrogen-containing hormone therapy. Your individual risk for cardiovascular events should inform your conversation with your doctor about the benefits and risks for hormone therapy for you.