Does Pregnancy Increase the Risk for Brain AVM Rupture?

Hooman Kamel, MD

A large, single-center, retrospective study suggests not, but the issue is not yet fully resolved.

Pregnancy increases the risks for ischemic and hemorrhagic stroke. Case reports and at least one single-center analysis suggest that this can be explained partly by an increased tendency for brain arteriovenous malformations (AVM) to rupture during pregnancy. By contrast, several other single-center analyses found no increased risk for AVM rupture during pregnancy compared with the nonpregnant state. To better understand the rupture risk associated with pregnancy, investigators at a single referral center in China have now performed an analysis of a large group of women with ruptured AVMs.

The study investigators identified 979 consecutive women referred to a single teaching hospital between 1960 and 2010 with an AVM confirmed by angiography or histology. Two key assumptions were made: that all patients had an AVM since birth, and that all ruptured AVMs in this group during childbearing age (18-40 years) were treated at the study hospital. The investigators calculated annual rates of AVM rupture during childbearing age and used case-crossover analysis to compare the odds of AVM rupture during pregnant versus nonpregnant periods.

A total of 393 patients had an AVM rupture during 16,367 patient-years of follow-up. The annualized hemorrhage rate during pregnancy was 3.32%, significantly lower than the 4.14% annual rate during nonpregnant periods (odds ratio, 0.71). Of the 12 patients with AVM rupture during pregnancy, 1 died and 7 were left with at least moderate disability.

Citation(s):

Liu X-j et al. Risk of cerebral arteriovenous malformation rupture during pregnancy and puerperium. Neurology 2014 May 20; 82:1798.