– Think of pregnancy as a cardiovascular stress test, Carole A. Warnes, MD, urged at the Annual Cardiovascular Conference at Snowmass sponsored by the American College of Cardiology.

Pregnancy complications may unmask a predisposition to premature cardiovascular disease. Yet a woman’s reproductive history is often overlooked in this regard, despite the fact that cardiovascular disease is the number-one cause of death in women, observed Dr. Warnes, the Snowmass conference director and professor of medicine at the Mayo Clinic in Rochester, Minn.

“I think reproductive history is often overlooked as a predictor of cardiovascular and even peripheral vascular events. I suspect many of us don’t routinely ask our patients about miscarriages and stillbirths. We might think about preeclampsia, but these are also hallmarks of trouble to come,” the cardiologist said.

Indeed, this point was underscored in a retrospective Danish national population-based cohort registry study of more than 1 million women followed for nearly 16 million person-years after one or more miscarriages, stillbirths, or live singleton births. Women with stillbirths were 2.69-fold more likely to have an MI, 2.42-fold more likely to develop renovascular hypertension, and 1.74-fold more likely to have a stroke during follow-up than those with no stillbirths.

Moreover, women with miscarriages were 1.13-, 1.2-, and 1.16-fold more likely to have an MI, renovascular hypertension, and stroke, respectively, than women with no miscarriages. And the risks were additive: For each additional miscarriage, the risks of MI, renovascular hypertension, and stroke increased by 9%, 19%, and 13%, respectively (Circulation. 2013;127[17]:1775-82).

The concept of maternal placental syndromes encompasses four events believed to originate from diseased placental blood vessels: preeclampsia, gestational hypertension, placental abruption, and placental infarction. In a population-based retrospective study known as CHAMPS (Cardiovascular Health After Maternal Placental Syndromes), conducted in more than 1 million Ontario women who were free from cardiovascular disease prior to their first delivery, 7% were diagnosed with a maternal placental syndrome. Their incidence of a composite endpoint comprised of hospitalization or revascularization for CAD, peripheral artery disease, or cerebrovascular disease at least 90 days after delivery discharge was double that of women without a maternal placental syndrome.

“These women manifested their first cardiovascular event at an average age of 38, not 50 or 60,” Dr. Warnes said.

The risk of premature cardiovascular disease was magnified 4.4-fold in women with a maternal placental syndrome plus an intrauterine fetal death, compared with those with neither, after adjustment for sociodemographic factors and other potential confounders, and by 3.1-fold in women with a maternal placental syndrome and poor fetal growth (Lancet. 2005;366[9499]:1797-803).

These findings were independently confirmed recently in a population-based retrospective study of nearly 303,000 Florida women free of prepregnancy hypertension, diabetes, heart disease, or renal disease who were followed for a median of 4.9 years after their first delivery. During that relative brief follow-up period, the adjusted risk of cardiovascular disease was increased by 19% in those with a maternal placental syndrome, compared with those without. And the risk was additive: women with more than one maternal placental syndrome had a 43% greater short-term risk of developing cardiovascular disease, compared with those with none. And when women with a maternal placental syndrome also had a preterm birth or a small-for-gestational age baby, their risk increased 45% (Am J Obstet Gynecol. 2016;215[4]:484.e1-484.e14).

It’s not just preeclampsia, which affects 3%-5% of all pregnancies, and gestational hypertension – defined as high blood pressure arising only after 20 weeks’ gestation and without proteinuria – that have been linked to future premature cardiovascular disease. In the Northern Finland Birth Cohort 1966, in which investigators have followed 10,314 women born in that year for 39 years, any form of high blood pressure during pregnancy was a harbinger of subsequent cardiovascular disease, diabetes, and chronic kidney disease. That included chronic isolated systolic and isolated diastolic hypertension (Circulation. 2013;127[6]:681-90).

The pathophysiologic processes involved in complicated pregnancies echo those of CAD and stroke: inflammation, altered angiogenesis, vasculopathy, thrombosis, and insulin resistance. Still unsettled, however, is the chicken-versus-egg question of whether preeclampsia and other pregnancy complications represent the initial expression of an adverse phenotype associated with early development of cardiovascular disease or the complications injure the vascular endothelium and thereby trigger accelerated atherosclerosis. In any case, markers of endothelial activation have been documented up to 15 years after an episode of preeclampsia, Dr. Warnes said.

All of these data underscore the importance of identifying at-risk women based upon reproductive history, scheduling additional medical checkups so they don’t drop off the radar for the next 20 years, encouraging lifestyle modification, and giving consideration to early initiation of antihypertensive and lipid-lowering therapies.

“Pregnancy complications give us a glimpse of this awful disease trajectory at a time when women are completely asymptomatic and we could intervene and perhaps change outcomes with targeted therapy when it might be expected to work better and patients might be more receptive to such interventions,” she said.

Dr. Warnes reported having no financial conflicts of interest.