NEW ORLEANS — Pregnancies and deliveries are on the rise while abortions are declining among women with congenital heart disease, according to a population-based Canadian study.
“These are very provocative findings. As the ACHD [adult congenital heart disease] population increases and ages, we can expect that more women will reach reproductive age. These demographic changes may therefore impact on transmission rates and health services utilization in the future,” Dr. Ariane J. Marelli said at the annual scientific sessions of the American Heart Association.
She and her coinvestigators have previously shown, using comprehensive Quebec-wide data, that women accounted for 57% of the province's ACHD population in the year 2000. That study, the first ever in which the prevalence of ACHD has been measured rather than merely estimated, showed that the prevalence of ACHD was 4.09 cases per 1,000 in the year 2000, with 9% consisting of severe forms (Circulation 2007;115:163-72). The prevalence of severe ACHD rose in Quebec by 85% from 1985 to 2000, probably because of the major surgical progress in this period.
In the new study of the Quebec population, which has universal access to health care, the investigators found that of 14,828 women with ACHD aged 18-45 years during 1992-2005, a total of 5,858 had 9,970 pregnancies. Thirty-two percent of ACHD patients in this age range had at least one delivery, and 14% had at least one abortion. The proportion of pregnancies resulting in delivery climbed from 61% in 1992 to 78% in 2004. Conversely, the proportion ending in abortion declined from 39% to 22%, according to Dr. Marelli, director of the McGill University adult unit for congenital heart disease, Montreal.
The median age at delivery among women with ACHD was 29, while the median age at abortion was 26.
“Over time, women are getting pregnant at an older age. Our women are following the same trend we're seeing in the normal population,” she noted.
The absolute number of deliveries annually among women with ACHD climbed by about 20% between 1992 and 2004. The C-section rate was unexpectedly high at 26.5%, roughly twice that in the general population.
“We were very surprised at the C-section rates,” Dr. Marelli said. “They're really very, very high. One has to wonder what the obstetricians are thinking. I can only surmise that it has taken us in cardiology at least a decade to feel a little more reassured [regarding pregnancy in ACHD patients], and they're probably not there yet. I think the responsibility is ours to help them get there.”
The study was supported by the Heart and Stroke Foundation of Canada and the Quebec Health Research Foundation.