Pregnancy Outcomes in Women With Transposition of the Great Arteries After an Arterial Switch Operation

Importance: A growing number of women are approaching childbearing age after arterial switch surgery for transposition of the great arteries. Prepregnancy counseling requires updated knowledge of the additional cardiovascular risks pregnancy poses for this cohort of women and the potential effect on their offspring; however, to our knowledge, this information is currently unknown. Objective: To determine the pregnancy outcomes of women with transposition of the great arteries after an arterial switch operation, as well as the outcomes of their offspring. Design, Setting, and Participants: This cohort study assessed women who had had arterial switch surgery from 1985 to the present and who were 16 years or older as of January 2018. All women with a previous arterial switch surgery for transposition of the great arteries with completed or ongoing pregnancy were included. Data were collected in a level 1 congenital cardiology center and joint obstetrics-cardiology clinic in Birmingham, United Kingdom. Exposures: Patients were assessed before, during, and after pregnancy. Main Outcomes and Measures: Adverse maternal cardiac events (arrhythmia, heart failure, aortic dissection, or acute coronary syndrome) and aortic root dilatation, aortic regurgitation, and left ventricular function before and after pregnancy were the main outcomes. Mode of delivery and fetal outcomes were considered secondary outcomes. Results: A total of 25 pregnancies were identified in 15 women; 8 women had had 1 pregnancy, while 7 were multiparous. There were no adverse maternal cardiac events. Before pregnancy, 8 women (53%) had no aortic regurgitation, 1 (7%) had a trivial degree of regurgitation, 4 (26%) had mild regurgitation, and 2 (14%) had moderate regurgitation. After pregnancies, 1 woman (7%) had minor progression of aortic regurgitation. Five women (36%) had mild neoaortic root dilatation prepregnancy, but none developed progressive dilatation in the first year post-partum. A total of 24 pregnancies were completed by the end of the study, with all infants born alive and well. Nineteen modes of delivery were known; there were 7 cesarean deliveries (37%), of which 2 (11%) were recommended for aortic dilatation and 5 (26%) for obstetric indications or maternal choice. Conclusions and Relevance: Pregnancy is well tolerated after arterial switch operation; no adverse maternal cardiac events or early progression of neoaortic root dilatation or aortic regurgitation were observed in this study. These results provide evidence to allow reassurance of women with previous arterial switch surgery who are planning pregnancies.