Women with heart disease are at greater risk than other women when going through a pregnancy, but most still have positive outcomes, a registry showed.
Compared with healthy pregnant women, those with structural or ischemic heart disease had higher rates of preterm birth (15% versus 8%), fetal death (1.7% versus 0.35%), and maternal mortality (1% versus 0.007%), but absolute rates remained relatively low, according to Jolien Roos-Hesselink, MD, of Erasmus Medical Center in Rotterdam, and colleagues.
The risks conferred by heart disease were magnified in women with cardiomyopathies and in those living in developing countries, the researchers reported online in the European Heart Journal.
However, they wrote, "most patients with adequate counseling and optimal care should not be discouraged and can go safely through pregnancy."
Because of a limited amount of data detailing the effects of heart disease on pregnancy outcomes, the European Society of Cardiology started the European Registry on Pregnancy and Heart Disease in 2007. The ongoing registry enrolls pregnant women who have valvular heart disease, congenital heart disease, ischemic heart disease, or cardiomyopathies.
For the current analysis, the researchers looked at data on 1,321 pregnant women who were enrolled from 60 hospitals in 28 countries from 2007 to 2011. The median age was 30.
Most of the patients (72%) were in New York Heart Association class I, and only 0.3% were in NYHA class IV.
The most frequent diagnosis was congenital heart disease (66%), followed by valvular heart disease (25%), cardiomyopathy (7%), and ischemic heart disease (2%).
The median duration of pregnancy was 38 weeks, and the median birth weight was 3,010 grams (6 pounds 10 ounces).
Thirteen of the mothers died -- seven from cardiac causes, three from thromboembolic events, and three from sepsis. The highest mortality rate occurred in patients with cardiomyopathy, who also carried higher rates of heart failure and ventricular arrhythmias.
"Cardiomyopathy is uncommon during pregnancy, but it is difficult to manage a pregnancy in the context of left ventricular dysfunction or peripartum cardiomyopathy with a high risk of an adverse outcome for both the mother and the baby," the authors noted. "Our study shows that more attention needs to be paid to this group."
During pregnancy, 26% of the women were hospitalized, a much higher rate than seen in healthy pregnant women (2%). More than one-third of the admissions (39%) were for heart failure; 31% were for obstetric reasons, including pregnancy-induced hypertension, vaginal bleeding, pregnancy-induced diabetes, and abortion/missed abortion; 21% were for cardiac reasons other than heart failure; and 9% were for other reasons.
The rate of cesarean delivery was significantly higher among the women with heart disease than has previously been seen in healthy pregnant women (41% versus 23%, P<0.001).
Fetal mortality beyond 22 weeks of gestation or when the fetus was greater than 500 grams (1 pound 2 ounces) occurred at a higher rate in the women with heart disease. Most of those cases (62%) were listed as intrauterine fetal death without any further information, 21% were attributed definitely to the mother's condition, and 17% were related to structural fetal abnormalities.
Neonatal mortality (within the first 30 days of life) occurred in 0.6%, a rate that was not significantly higher compared with historical controls (0.4%, P=0.27).
Women living in developing countries (185 of the registry patients) carried greater risks of both maternal mortality (3.9% versus 0.6%, P<0.001) and fetal mortality (6.5% versus 0.9%, P<0.001).
The authors noted that developed countries have much greater access than developing countries to optimal prenatal care and preconception counseling, even if it isn't used in all cases.
"This is a very complex issue, but if achievable, pre-conception counseling focusing on the severity of the heart disease with a clear statement of the consequences of pregnancy may save lives," they wrote.
The researchers acknowledged some limitations of the study, including the inability to perform extensive subgroup analyses because of small patient numbers, the fact that the input and quality of data was checked in only 5% to 10% of cases, and uncertainty about how representative the patient population is, considering the voluntary participation in the registry.
From the American Heart Association:
Primary source: European Heart Journal
Roos-Hesselink J, et al "Outcome of pregnancy in patients with structural or ischemic heart disease: results of a registry of the European Society of Cardiology" Eur Heart J 2012; DOI: 10.1093/eurheartj/ehs270.