Introduction: The progress in medical technology has led to rapid increases of adult survivors with congenital heart disease (CHD) and many women with CHD survive to childbearing age. Although many of them are at high risk of cardiovascular complications during the perinatal periods, the prevalence and predictors have not been established. We retrospectively studied the multicenter data on pregnant CHD-women.

Purpose: To investigate the prevalence of perinatal cardiovascular events (CVE) and identify clinical factors related to the CVE.

Methods: As a multicenter study including 4 center hospitals specific to CHD-patient care, we surveyed medical records of 243 pregnant CHD-women. We obtained patients characteristics such as age, NYHA functional class, underlying CHD, operations for CHD, medication, and data related to delivery and amount of intrapartum hemorrhage. We classified the pregnant women into 3 groups; simple CHD (n=123, e.g., atrial septal defect, aortic valve disease and mitral valve disease), moderate (n=82, e.g., tetralogy of Fallot, atrioventricular septal defect, and complicated ventricular septal defect), and great complex (n=38, e.g., transposition of the great arteries, double outlet right ventricle, and single ventricle). CVE included heart failure and arrhythmias requiring management. We retrospectively followed the pregnant women from the perinatal period up to 1 year after the delivery. We used T test, Mann Whitney U test, Chi-squared test, and general liner model for statistical analysis.

Results: The number of deliveries was 1.5±0.7 times and Caesarian section was performed in 35% of the women. Intrapartum hemorrhage was 604±363 ml. The average age was 31±6 years, and NYHA class I/II were observed in 93/7%. CVE occurred in 38 women (15.6% of 243 CHD-women); 3 in the simple (2.4% of 123), 16 in the moderate (19.5% of 82), and 19 in the great complex CHD (50% of 38). The more complex CHD-women suffered the more CVE; simple/moderate/great-complex CHD were 7.9/42.1/50% of 38 women with CVE vs. 58.5/32.2/9.3% of those without CVE, P<0.001. Heart failure was observed in 28, arrhythmias requiring treatments in 6, and both in 4. The women with CVE showed lower functional class than those without (NYHA II: 26.5% vs. 3.5%, P<0.001). Arrhythmic events were observed during both pregnancy and postpartum but heart failure was observed only during postpartum period. These complications were not continued 1 year after delivery. Multivariate analysis identified that CHD of moderate or great complexity with lower functional class were predictors of CVE even after the adjustment for confounding factors (simple vs. moderate: OR [95%Cl] = 7.91 [2.10–29.85], P=0.002; simple vs. great: OR [95%Cl]=4.75 [2.30–9.81], P<0.001; NYHA class: OR [95%Cl] = 4.53 [1.17–17.47], P=0.028).

Conclusions: Meticulous care should be taken for prevention of cardiovascular events to the women with moderate to severe CHD and low functional class during perinatal period.