Pregnancy: the risk of myocardial 30 times higher after 40 years

Women over age 40 are 30 times more likely than those aged 20 to suffer a myocardial infarction during pregnancy or postpartum, according to a study published in the journal "Circulation".

The rarity of pregnancy-related stroke makes it difficult to estimate their incidence (number of new cases per year) and the identification of risk factors. A previous study was first conducted across California and Dr. Andra James and his colleagues at Duke University Medical Center in Durham (North Carolina) wanted to obtain data at the entire United States.

The researchers used the Nationwide Inpatient Sample, which collects most of the data on obstetric complications through hospital discharge records.

Between 2000 and 2002, 859 hospitalizations included a diagnosis of myocardial infarction, an incidence of 6.2 per 100,000 live births, three to four times higher than what was expected based on the incidence of myocardial infarction in women of childbearing age, followed within a network of care HMO (Health Maintenance Organization).

The infarction was fatal in 5.1% of cases. The risk of pregnancy was 30 times higher among women 40 and older, compared with less than 20 years.

The authors have also identified several risk factors associated with pregnancy infarction: thrombophilia this risk multiplied by 25.6, 21.7 by hypertension, smoking by 8.4, a transfusion during the childbirth by 5.1, 3.6 and diabetes by infection postpartum 3.2.

However, black women were not more likely than others to suffer a heart attack during pregnancy, suggesting that the higher incidence generally observed in this population must be explained by a greater prevalence of other cardiovascular risk factors, the authors note.

"Screening and preventive measures should target women whose pregnancy is late or who have coronary risk factors known thrombophilia or have postpartum complications, and smoking," conclude the investigators.