Increasingly, women born with complete transposition of the great arteries who have undergone atrial repair by either the Senning or the Mustard procedure are reaching childbearing age. This study reports on pregnancy outcomes after the atrial repair of transposition of the great arteries. Record review and standardized questionnaires were used to ascertain the outcomes of 70 pregnancies reported in 40 women (36 Mustard procedures, 4 Senning procedures). Of the 70 pregnancies, 54 resulted in 56 live births, 10 in miscarriages, and 6 in therapeutic abortions. At pregnancy, 31 women were in New York Heart Association class I, 8 were in class II, and 1 was in class III. Thirty-nine percent of the infants were delivered prematurely and weighed 2,714 +/- 709 g; 28% were delivered by cesarean section, 8 for cardiac indications. Maternal complications included arrhythmias in 5 women and hemoptysis in 2 women. Heart failure occurred in 6 women, developing during the second and third trimesters. Postpartum cardiac events developed 2 to 9 days postpartum: heart failure in 5 women, atrial fibrillation in 1 woman, and decreased oxygen saturation due to a new atrial baffle leak in 1 woman. Severe right ventricular (RV) failure led to cardiac transplantation after delivery in 1 woman; another developed heart failure and then died suddenly 1 month after delivery. There was 1 late death, 4 years after the patient's last pregnancy. In conclusion, pregnancy after atrial repair carries a moderate degree of risk and should be undertaken with caution.