Intracranial Arteriovenous Malformations During Pregnancy and Puerperium-A Retrospective Nationwide Population-Based Cohort Study.

Background and objectives: The knowledge about the management of patients with brain arteriovenous malformations (AVM) during pregnancy is limited, owing partly to insufficient evidence about the outcomes of newborns. This study aims to explore symptomatic AVMs and their outcomes during pregnancy, delivery, and the postpartum period.

Methods: We conducted a retrospective analysis by combining patients with symptomatic AVM from a nationwide population-based cohort of all women with a pregnancy resulting in delivery during 1987 to 2016 (n = 1 773 728 deliveries) and our AVM database (n = 805, 1942-2014). Cerebrovascular events during pregnancy were identified through International Classification of Diseases-9, International Classification of Diseases-10, or surgical procedure codes from the Hospital Discharge and Medical Birth Registers. Our analysis focused on treatment characteristics and outcomes of patients with AVM hemorrhage or symptomatic AVM during pregnancy, delivery, or puerperium.

Results: A total of 28 women with symptomatic AVMs during pregnancy, delivery, or postpartum period were followed for an average of 12.8 years (SD = 15.5) after admission. Among them, 21 (75%) experienced AVM hemorrhages during pregnancy, puerperium, or delivery. The mean age of patients was 28.9 years (SD = 5.5). Hemorrhages occurred predominantly during the second (n = 9, 43% of all ruptures) or the third trimester (n = 5, 24%). Two AVM ruptures occurred during labor. Treatment for AVM took place during pregnancy (n = 7, 25%) or puerperium (n = 3, 14%) in 10 patients (35.7%). Only 5 mothers (17.8%) had not been previously pregnant. There was no significant difference in mean Apgar scores between those with AVM hemorrhage (8.3) and those without (8.4).

Conclusion: Most mothers in the study had prior pregnancies, suggesting a potentially weaker association between AVM rupture and pregnancy compared to previous reports. Notably, 2 AVM ruptures occurred during spontaneous vaginal deliveries. Outcomes were generally favorable in both mothers and infants. More research is needed to refine our understanding of the optimal timing for invasive treatment during pregnancy.