NEW YORK (Reuters Health) – Women with a history of an atrial switch procedure for congenital d-transposition of the great arteries are at risk of untoward pregnancy outcomes, researchers report in a June 20th online paper in the American Journal of Obstetrics and Gynecology.

“These patients,” Dr. Torri D. Metz told Reuters Health by email, “should be aware of the high rate of preterm birth and transient decrease in right ventricular function noted during pregnancy.”

Dr. Metz and colleagues at the University of Utah, Salt Lake City note that the procedure which became widespread in the 1970s allowed long-term survival of patients who had previously died in infancy. Many are now of childbearing age.

To gain further information, the team retrospectively examined data on 25 such women who were seen at 2 centers over a period of 10 years. One died and 2 underwent cardiac transplantation.

All of the remaining 22 were interested in pregnancy. There were 21 pregnancies resulting in 14 live births. The spontaneous abortion rate was 29% and the preterm birth rate was 50%. There were no deaths.

There were pregnancy complications in 5 of the women. In the 10 women monitored, there also was a fall in right ventricular function during pregnancy with some improvement postpartum.

Symptomatic baffle obstruction requiring postpartum stenting occurred in 5 of the 14 (36%) pregnancies resulting in live births.

“This study,” continued Dr. Metz, “provides us with a base to begin counseling women with a history of an atrial switch procedure for congenital d-transposition of the great arteries regarding pregnancy outcomes.”

She concluded that “We recommend that they are followed closely by a perinatologist and cardiologist with expertise in adult congenital heart disease. As more women with congenital heart disease are achieving reproductive age with reasonable cardiac function, there is a greater need for literature in this area to guide providers in counseling this unique group of patients.”

Am J Obstet Gynecol 2011.