Women who experience preeclampsia during pregnancy are almost twice as likely to have a heart attack or stroke within 20 years of giving birth as pregnant women who did not, according to a new study published in the European Journal of Preventive Cardiology. The risks are especially high in the first decade after giving birth, the researchers found.
Preeclampsia is the onset of high blood pressure after the 20th week of pregnancy combined with signs of organ damage, such as excess protein in the urine. It can occur in up to 8% of pregnancies, and the association between preeclampsia and long-term cardiac risks is well-known. But new research suggests these risks appear much earlier in life than expected – as early as age 30 – at a time when women are often not screened for signs of heart trouble
“Targeted interventions cannot wait until women with preeclampsia become eligible for conventional screening programs in middle age,” Sara Hallum, PhD, a coauthor of the study, told this news organization.
Dr. Hallum, who was an epidemiologist at the University of Copenhagen at the time of the study, and colleagues evaluated the medical histories of more than 1.1 million women in Denmark who became pregnant once or twice between 1978 and 2017. Of this group, 3% had experienced preeclampsia. They compared rates of heart attack and stroke between the two groups over time.
While 1.2% of the entire study population had experienced a heart attack or stroke within 20 years of giving birth, 2% of the women with a history of preeclampsia had such an event. Within the first decade after delivery, women with a history of preeclampsia were four times as likely to have a heart attack and three times as likely to have a stroke as other women.
Women aged 30-39 with a history of preeclampsia were nearly five times as likely to have a heart attack and three times as likely to have a stroke as similar-aged women. And if a woman gave birth twice and had preeclampsia only during the second pregnancy, she was at especially high risk for a heart attack, the researchers found.
“Women with a history of preeclampsia should be monitored routinely for modifiable risk factors, particularly for increased blood pressure,” Dr. Hallum said.
The Danish study population is racially homogeneous, so the researchers were not able to distinguish the effects of preeclampsia by racial group. In the United States, strong evidence shows that Black women experience the effects of preeclampsia more than others.
A useful clue to cardiac risk
Ellen Seely, MD, an endocrinologist at Brigham and Women’s Hospital in Boston, who specializes in preeclampsia, said physicians are less likely to ask women who have been pregnant if they had experienced preeclampsia than to ask if they smoke or have a family history of heart attacks. As a result, they may miss a looming cardiovascular event, especially in younger women who appear healthy.
“Emerging high blood pressure shouldn’t be ignored” in a seemingly healthy young woman, Dr. Seely said, particularly if that woman has divulged a history of preeclampsia. The doctor’s first step should be to verify hypertension, Dr. Seely said. If high blood pressure is evident, immediate treatment – such as encouraging more physical activity and a healthier diet – should follow. Watchful waiting in such cases is inappropriate, she added.
Although the experience of having preeclampsia is unpleasant and scary, Dr. Seely noted that in at least one way it can prove advantageous. Some women who did not experience preeclampsia will end up having a heart attack, sometimes with no prior warning that anything was amiss. At least a history of preeclampsia provides a clue that women should take care of their hearts.
“The patient carries their history with them wherever they go,” Dr. Seely said. For now, this reality often requires women to mention their pregnancy history even if a provider doesn’t ask. Someday, Dr. Seely said, asking about that history will become just as routine for providers as asking about family history.
The study was funded by the Danish Heart Foundation. Dr. Hallum and Dr. Seely have reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.