MedPageToday
Published: Jul 15, 2014
By Crystal Phend, Senior Staff Writer, MedPage Today

Action Points

• Miscarriages and stillbirths might be a marker for women at higher risk of developing heart disease later in life.
• The study suggests that physicians should now include stillbirth or miscarriage on their list of items to ask about in screening for cardiovascular disease.

Miscarriages and stillbirths might be a marker for women at higher risk of developing heart disease later in life, an observational study suggested.

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Coronary heart disease risk was 27% higher for women who had a history of stillbirth compared with none (multivariate adjusted odds ratio 1.27, 95% CI 1.07-1.51), Donna R. Parker, ScD, of Memorial Hospital of Rhode Island in Pawtucket, and colleagues found.

That risk was a significant 18% to 19% elevated among women with one or two prior miscarriages compared with none in an analysis of the Women’s Health Initiative (WHI) observational cohort appearing in the July/August issue of theAnnals of Family Medicine.

“Women with a history of one or more stillbirths or one or more miscarriages appear to be at increased risk of future cardiovascular disease and should be considered candidates for closer surveillance and/or early intervention,” they urged.

The American Heart Association guidelines already include pregnancy complications as a risk factor for cardiovascular disease in women due to growing evidence for an association, but these don’t address long-term cardiovascular implications of pregnancy loss, the group pointed out.

Physicians should now include stillbirth or miscarriage on their list of items to ask about in screening for cardiovascular disease, argued Roxana Mehran, MD, of Mount Sinai School of Medicine in New York City, who was not involved in the study.

“This is so important because the prevalence of pregnancy loss is increasing as the [average] age of women who are becoming pregnant is increasing,” she told MedPage Today.

Women with a history of pregnancy loss perhaps should be screened earlier, agreed Mehran, the founding and immediate past chair of the Society for Cardiovascular Angiography and Interventions’ Women in Innovations program, working with ob/gyns to promote screening women for cardiovascular risk factors.

However, this information, like that of other pregnancy complications, is typically lost to medical history by the time women reach the cardiologist or are screened for heart disease prevention, she noted.

The mechanism for the association isn’t clear, but “there appears to be a relationship between the metabolic syndrome, abnormal implantation, and endothelial dysfunction,” Parker and colleagues noted.

“Specifically, it has been suggested that the endothelial dysfunction resulting from systemic inflammatory processes may be involved. The resulting vascular pathology may thus contribute to both poor placentation during pregnancy (resulting in pregnancy loss) and an increased likelihood of cardiovascular disease.”

Further research is needed to better understand the pathophysiology behind the link, the group suggested.

Their analysis included 77,701 postmenopausal women, ages 50 to 79, in the WHI observational study (not the clinical trial portion) who were free of cardiovascular disease at baseline in 1993-1998 and reported being pregnant at some point in their reproductive history.

Among them, 30.3% self-reported a history of miscarriage, 2.2% reported a history of stillbirth, and 2.2% reported both.

During the mean 7.7 years of follow-up for cardiovascular disease incidence, associations with ischemic stroke were mostly not significant.

The only potential association with ischemic stroke was for a history of stillbirth, with an age-adjusted OR of 1.29 (95% CI 1.03-1.60), but which lost significance after multivariate adjustment (OR 1.13, 95% CI 0.89-1.43).

The associations between heart disease and pregnancy loss, though, were independent of hypertension, body mass index, waist-to-hip ratio, and white blood cell count.

Mehran cautioned about the limitations of retrospective recall and possible unmeasured confounding, but still called the findings important.