Description Background: Maternal congenital heart disease (CHD) is the most common cardiac condition to complicate pregnancy and women now become pregnant even with complex CHD. The Registry Of Pregnancy And Cardiac disease (ROPAC) examines the relationship between maternal heart disease and pregnancy outcome. Methods: The ESC EORP ROPAC is a worldwide prospective registry of pregnancies in women with structural heart disease (n= 5739, recruiting between 2007-2018), including CHD. Maternal and fetal outcomes were examined in all women with CHD. Multivariable regression was used to identify associations with a composite endpoint of maternal mortality and/or heart failure. Results: In CHD pregnancies (n= 3295, mean age 29 years), maternal mortality was 0.3% and heart failure occurred in 6.6%. Preterm births (16%) and Caesarean section (46.3%) were higher than global averages, but otherwise cardiac, obstetric and fetal outcomes were good. The composite endpoint was highest in complex CHD: Eisenmenger syndrome (58.1%), congenitally corrected transposition of the great arteries (12.8%), Fontan circulation (11.2%), double outlet right ventricle (11.1%). Pre-pregnancy signs of heart failure (OR 10.6, 95% CI 7.1-16), multiple gestation (4.6, 2-10.8), pulmonary hypertension (2.5, 1.5-4), estimated LVEF< 40%(2.4, 1.1-5.1), cardiac medication use (2, 1.4-2.7) and low-or middle-income country (1.6, 1.1-2.4) were independently associated with the composite endpoint. Conclusion: Overall pregnancy outcomes for women with CHD are good but women with complex CHD are at increased risk of complications. Pre …