369. Obstetric outcomes following atrial and arterial switch procedures for transposition of the great arteries – A single, tertiary referral centre experience over 20 years

Abstract

Complete transposition of the great arteries (TGA) accounts for approximately 5–7% of CHD. Almost all patients with TGA surviving until adulthood have undergone complex, reparative, cardiac surgery, which can complicate physiological adaptation to the demands of pregnancy. The atrial switch procedure (Mustard or Senning procedure) was the first operation to enable survival beyond infancy, as such, pregnancy outcomes have been well described. Cardiac risks of pregnancy include cardiac deterioration, heart failure and arrhythmias. The pregnancy risks include; pre-term delivery (31–38%) and neonates which are small for gestational age (SGA) (22–38%). The arterial switch operation (ASO) has now largely superseded the atrial switch procedures, this involves transection and ‘re-plumbing’ of the great arteries to restore near normal anatomy, it follows that adult survivors are now undertaking the challenges of pregnancy. Our unit is an adult congenital heart disease (ACHD) centre and tertiary level maternal medicine service with over twenty years’ experience in the multi-disciplinary team (MDT) management of women with surgically corrected TGA in pregnancy. Here we report and compare obstetric outcomes in women born with TGA, corrected with either an atrial switch procedure or ASO. This is the largest, cohort of pregnancies, with complete obstetric and neonatal outcomes, born to women following an ASO, reported to date and the only comparison of outcomes by procedure. There were 48 completed pregnancies in 23 women, 19 women who had undergone an atrial switch procedure delivered 38 babies and 4 who had undergone an ASO had 10 babies. We report obstetric and neonatal outcomes for all pregnancies, based upon which we make recommendations for the obstetric care of women with this condition.