Risk of complications during pregnancy after Senning or Mustard (atrial) repair of complete transposition of the great arteries

Aims To investigate magnitude and determinants of risks during pregnancy in women with Mustard or Senning repair for complete transposition of the great arteries (TGA). Methods and results Using a nationwide registry (CONCOR), 70 women with Senning (23%) or Mustard (77%) repair for TGA were enrolled. A total of 28 patients had 69 pregnancies (two twins), including 17 spontaneous miscarriages and three elective abortions. During 39 of the 49 completed pregnancies, complications were observed. The most important cardiac complication was clinically significant arrhythmia (n=11, 22%), especially occurring in patients with a prior history of arrhythmia. Important general pregnancy complications were preeclampsia (n=5, 10.2%) and pregnancy-induced hypertension (n=4, 8.2%). Obstetric complications included premature rupture of membranes (n=7, 14.3%), premature labour (n=12, 24.4%), premature delivery (n=16, 31.4%), and thrombo-embolic complications (n=2, 4.1%). Mean (singleton) pregnancy duration was 36 +/- 5 weeks. Eleven of the 51 children (21.6%) were small for gestational age. Foetal and neonatal mortality combined was 11.8% (n=6). No recurrence of congenital heart disease in the offspring was documented. Conclusion In this largest report on pregnancy in women with atrial-corrected TGA to date, a high incidence of obstetric complications and mortality in the offspring was observed.