Pregnancy-Related Vascular Outcomes in Loeys-Dietz Syndrome: A Retrospective Cohort Study and Case Series

Background: Loeys-Dietz syndrome (LDS) is an autosomal dominant aortopathy characterized by aggressive aneurysm formation and arterial dissections. Pregnancy-related outcomes and timing of LDS diagnosis remain poorly characterized. Methods: Demographics, genetic, obstetric, and vascular data was collected from genetically or clinically confirmed individuals with LDS seen at the three Mayo Clinic sites from 2018 to 2025. Aneurysm progression, new aneurysm formation, and arterial dissections were recorded across all vascular beds. Vascular events were assessed during pregnancy, within 12 months postpartum, and during breastfeeding. Comparative analyses were performed between women with and without a history of pregnancy, and a single-arm descriptive analysis was conducted among patients who experienced vascular complications during the peripartum period. Continuous variables were compared using the Mann-Whitney U test, while categorical variables were analyzed using chi-square or Fisher exact tests. Results: Of 47 women with LDS, 24 had a history of pregnancy, accounting for 54 pregnancies. In the comparative analysis, age at LDS diagnosis differed significantly between women with and without a prior pregnancy: women without prior pregnancy were diagnosed at a younger age (median 23.5 years [IQR 10.8-41.0], n = 23) than those who had been pregnant (median 53.5 years [IQR 43.0-59.3], n = 24). Among pregnant women, the median age at first pregnancy was 28 years (IQR 23-34); only 4 (16.7%) knew their diagnosis before pregnancy. Of 54 pregnancies, 40 (74.1%) resulted in live birth, with 23 (57.5%) vaginal and 17 (42.5%) cesarean deliveries; preterm delivery occurred in 1 (2.5%) pregnancy, and postpartum hemorrhage in 2 (5.0%). No maternal deaths, aortic dissections, or uterine ruptures occurred during gestation or the first postpartum year. In addition, 14 women (58.3%) developed aneurysms, 6 (25.0%) experienced at least one arterial dissection, and 7 (29.2%) required surgical repair, predominantly involving the ascending and abdominal aorta. The prevalence of vascular complications did not differ significantly between groups. Conclusions: In this LDS cohort, pregnancy and the early postpartum period were not accompanied by acute aortic catastrophes, despite frequent diagnostic delay. Although women without prior pregnancy were diagnosed at a younger age, the overall burden of vascular and morphologic complications did not differ significantly by pregnancy history. These findings highlight the importance of long-term cardiovascular follow-up in women with LDS.