Cardiac Disease in Pregnancy

Abstract

Although maternal mortality has declined steadily over the past 2 decades, the proportion of heart disease among all causes of mortality has remained unchanged. Reported rates of heart disease in pregnancy range from 0.9%to 3.7%. The authors retrospectively studied 207 pregnancies encountered in the years 1994 to 2000 at a tertiary care center. These women had cardiac disease and delivered at or after 28 weeks gestation. Those whose cardiac status was becoming worse or who were already in New York Heart Association (NYHA) class III/IV were hospitalized. Heparin treatment was stopped when labor began. Labor was induced only for obstetric reasons, using oxytocin cautiously. All women were kept propped up and given oxygen intermittently, and the second stage of labor was shortened if indicated by using outlet forceps or vacuum extraction. A majority of these women were multigravidas and ranged in age from 18 to 35 years. Rheumatic heart disease was present in 88% of pregnancies, most often in the form of isolated mitral stenosis. Another 24 women had congenital heart disease. Pregnancies occurred an average of 6.6 years after the diagnosis of heart disease, but in 13% of cases, it was diagnosed during the index pregnancy. One in 5 women were in NYHA class III/IV at the first antenatal visit. New-onset cardiac complications occurred in 30% of pregnancies. Women in NYHA classes I/II had fewer complications, and their infants were heavier at birth than those in the class III/IV group. The hospitalization rate before 37 weeks gestation was 55%, and the mean hospital stay was 2 weeks. All but 20% of women delivered vaginally. The cesarean section rate was 46% in women with the most advanced cardiac disease. Fetal complications occurred in 20% of pregnancies but there were no infant deaths. Cardiac interventions were necessary before pregnancy in 61% of women with rheumatic heart disease. Both maternal and fetal outcomes were better in women with prosthetic valves, a large majority of whom remained in NYHA class I/II. Ten women had interventions while pregnant; one of them developed congestive heart failure during labor. None of 41 newborn infants whose mothers had received anticoagulants had congenital malformations. These results emphasize the need for prepregnancy counseling of women with heart disease to ensure close surveillance during pregnancy. Early diagnosis is important, as is the surgical correction of cardiac lesions when indicated.