"Some of these women do get pregnant against advice," she added. "Especially, we have seen this happen in Egypt," she said, noting that women who wanted a pregnancy for cultural reasons might not tell their husbands that they had heart defects.
Significant differences were found between developed and developing countries in maternal mortality (0.6% vs. 3.9%) and fetal death (0.9% vs. 6.5%), although the authors acknowledged that any between-country comparisons were "very fragile" because the size of the populations was "grossly unbalanced."
"Most women with adequate counseling and optimal care should not be discouraged and can go safely through pregnancy," the authors concluded.
In terms of counseling, Dr. Johnson said it’s important to give as accurate a picture as possible of the risks to which the woman would be exposing herself and her baby.
"In terms of management, the early recognition of a problem and its prompt management is really important, from things as simple as anemia or a urinary tract infection to the more severe situation of a cardiac arrhythmia or the development of heart failure," he said.
Dr. Roos-Hesselink said the standard at her clinic is to perform an echocardiogram and exercise test prepregnancy, with other tests such as magnetic resonance imaging done if needed. Symptomatic patients must be treated and a dilated aorta corrected prior to pregnancy.
"If the woman has a bad exercise capacity, this gives you an idea she will do badly during pregnancy," she added.
The study was supported by the European Society of Cardiology. The authors reported they have no conflicts of interest.