Pregnancy in Women with Congenital Heart Disease – Complications, Maternal and Neonatal Outcomes: A Retrospective, Multicenter Analysis

Background
Due to medical advances, over 95% of patients with congenital heart disease (CHD) reach adulthood in industrialized countries. Consequently, more women with CHD attain childbearing age. The ESC Guidelines for the management of cardiovascular disease during pregnancy provide recommendations for this particular patient group; however, real-world data on care structures in terms of pregnancy heart teams as well as maternal and neonatal complications during pregnancy are scarce.

Objectives
The aim of this multicenter, observational study was to analyze the frequency of pregnant women with CHD according to the modified World Health Organization (mWHO) scale and to investigate the influence of the underlying CHD, clinical characteristics and mode of delivery on maternal and neonatal complications.

Methods
Data from female CHD patients were retrospectively analyzed after childbirth at three certified centers for adult CHD in Germany between 2020 and 2022. Clinical and echocardiographic parameters were assessed at baseline and during the perinatal period stratified by the complexity of the underlying CHD (mWHO risk scale I/II vs. III/IV).

Results
A total of 86 women with CHD (median age: 31 (19/42) years) were included in the study. The most common underlying CHD were tetralogy of Fallot (17.4 %), transposition of the great arteries (12.8 %) and bicuspid aortic valve (11.6 %). 33 patients (38.4 %) were classified as having high risk pregnancies being assigned to mWHO III or IV. 75.6 % of the total cohort underwent prior heart surgery. At baseline, only few patients were severely symptomatic (NYHA functional class III/IV: 7.0 %). Almost half of all patients (44.2 %) were discussed within an interdisciplinary pregnancy heart team. Vaginal delivery was the most frequently recommended mode of delivery (60.5 %) whereas cesarean section emerged as the most common definitive mode of delivery (58.1 %) (Fig.1). Prematurity and neonatal low birth weight occurred significantly more often in patients with complex CHD (42.2 % vs. 13.2 %  (p = 0.003) and 51.5 % vs. 22.6 %  (p = 0.007)), respectively (Table 1). In binary logistic regression analysis, the complexity of CHD was a significant predictor of overall perinatal complications (OR 3.08 [95% CI: 1.06-9.0], p = 0.039) whereas the mode of delivery did not have a significant impact (OR 1.06 [95% CI: 0.39-2.87], p = 0.91).

Conclusion
In this real-world, multicenter analysis, maternal cardiovascular complications were generally rare and high-risk pregnancies could be successfully managed in certified CHD centers. Complex CHD in pregnant women was significantly associated with increased rates of neonatal complications.

	Total (n = 86)	mWHO Risk Scale I- II (n = 53)	mWHO Risk Scale III- IV (n = 33)	p-value
Maternal Complications, Total, n (%)	30 (34.9)	15 (28.3)	15 (45.5)	0.1
-        Cardiovascular Complications, n (%)	3 (3.5)	2 (3.8)	1 (3.0)	0.87
-        Bleeding, n (%)	9 (10.5)	3 (5.7)	6 (18.1)	0.06
-        Preeclampsia, n (%)	4 (4.7)	1 (1.9)	3 (9.1)	0.12
-        Premature Rupture of Membranes, n (%)	8 (9.3)	5 (9.4)	3 (9.1)	0.98
Neonatal Complications, Total, n (%)	38 (44.2)	19 (3.6)	19 (57.6)	0.06
-        Prematurity, n (%)	21 (24.4)	7 (13.2)	14 (42.2)	0.003
-        Low Birth Weight, n (%)	29 (33.7)	12 (22.6)	17 (51.5)	0.007
-        Congenital Heart Disease, n (%)	3 (3.5)	2 (3.8)	1 (3.0)	0.82

Table 1- Perinatal maternal and neonatal complications. Abbreviations: mWHO risk scale, modified World Health Organization risk scale.