Introduction: Pregnant women with adult congenital heart disease (ACHD) are at high risk of complications and may require interventions, including valvular surgery, after delivery. However, data on the long-term need for valvular surgery among pregnant women with ACHD are limited. Hypothesis: We hypothesized that increasing ACHD complexity and obstetric history are associated with the need for valvular surgery after delivery. Methods: Data from the University of Pittsburgh Medical Center clinical data warehouse were linked to all deliveries from 2004 to 2020 in pregnant women with ACHD (N=430) and without ACHD (N=876), who were included in the Magee Obstetric Maternal and Infant (MOMI) study. Women were matched at the delivery level for age, delivery year, and race. Valvular procedures were captured using Current Procedural Terminology codes until 8/31/2022. Results: Baseline characteristics and pregnancy outcomes are presented in Table 1 . Prior to index delivery, 8 women (6 with ACHD, 2 controls) had a valve replacement, Table 1. After a median of 5.1 (2.8, 8.8) years, 23 women with ACHD had a total of 25 valve procedures, corresponding to 1.0% per year (95%CI: 0.6 to 1.4). Most procedures were aortic valve (n=11, plus aortic root in 5) and pulmonary valve replacements (n=11), followed by tricuspid (n=5) and mitral (n=1) procedures; some women had >1 valve replaced in the same procedure. There were no valvular interventions among controls. After adjusting for maternal age and race, the strongest predictor of need for valvular interventions was ACHD complexity. Compared to simple lesions; moderate ACHD had a HR of 6.58; 95%CI 1.85 - 23.4; P=0.004 and complex ACHD a HR of 9.35; 95%CI 1.37 - 64.0; P=0.023). The number of previous deliveries (or total pregnancies) was not associated with the need for valvular procedures. Conclusions: Women with moderate or complex ACHD have increased rates of valvular procedures after delivery, but multiple pregnancies do not modify this risk.