Women who have placental syndromes are at high risk for premature cardiovascular disease, particularly if there is associated fetal compromise, according to Joel G. Ray, M.D., of the University of Toronto, and his associates.
The level of cardiovascular risk conferred by a placental syndrome—preeclampsia, gestational hypertension, placental abruption, or placental infarction—is comparable with that of such conventional risk factors as hypertension, obesity, diabetes, and dyslipidemia. “We believe that maternal placental syndrome should be considered an additional risk factor for cardiovascular disease in women, especially when the woman's fetus is adversely affected,” Dr. Ray, of the division of obstetrics and gynecology at the university, and his associates said (Lancet 2005;366:1797–803).
They assessed outcomes in a population-based study of Ontario residents who gave birth between 1990 and 2004. The mean maternal age at delivery was 28 years. Of 1,026,265 subjects, 75,380 (7%) were diagnosed as having a placental syndrome.
After a mean of 8.7 years' follow-up, cardiovascular events occurred in more than twice as many women with placental syndromes as in women without placental syndromes, irrespective of the presence of potential confounders such as diabetes. The rate of events was 500/million person-years among those with placental syndromes, compared with 200/million in those without placental syndromes.
The women's mean age was 38 years at the time of the first cardiovascular event. These included coronary, cerebrovascular, or peripheral artery events, or the need for a revascularization procedure.
The risk for cardiovascular events was even higher if the placental syndromes led to fetal growth restriction or intrauterine fetal death. It was higher still in women who had preexisting cardiovascular risk factors when they became pregnant, such as smoking or various features of the metabolic syndrome.
The findings do not imply placental disorders cause cardiovascular events to occur in the near future, the investigators said. “Rather, a more plausible explanation relates to a woman's abnormal metabolic milieu that predates her pregnancy and continues after delivery. This chronic state of dysmetabolism might create an inhospitable environment during the development of the placental spiral arteries, which can adversely affect fetal health, while negatively affecting the large arteries of a woman's heart, brain, and extremities over a broader period of time,” they noted.
Physicians “should try to ensure that women are a healthy weight before they enter their reproductive years.” This should reduce their risk for placental syndromes and fetal compromise as well as for cardiovascular disease, the researchers said.
It remains unknown whether women who have had placental syndromes might lower their risk of premature cardiovascular disease by making lifestyle changes, they added.