By Matthew E. Fink, MD

Professor and Chairman, Department of Neurology, Weill Cornell Medical College; Neurologist-in-Chief, New York Presbyterian Hospital

Dr. Fink reports he is a retained consultant for Procter & Gamble and Pfizer.

SOURCE: Porras JL, Yang W, Philadelphia E, et al. Hemorrhage risk of brain arteriovenous malformations during pregnancy and puerperium in a North American cohort. Stroke 2017;48:1507-1513. doi: 10.1161/STROKEAHA.117.016828.

The risk of hemorrhage in a pregnant woman with a brain arteriovenous malformation (AVM) is uncertain and management is controversial. Investigators at Johns Hopkins Medicine retrospectively reviewed female patients with AVMs evaluated from 1990 to 2015. They considered the exposure during pregnancy up to 40 weeks and the puerperium for six weeks postpartum, for each full-term pregnancy, and a six-week exposure for each abortion. Hemorrhage events and patient years were calculated for both the exposure as well as non-exposure, defined as either the interval from birth until AVM obliteration or until the last follow-up after subtracting the exposure. A ratio test was used to compare the rate of hemorrhage between the exposure and nonexposure periods.

Two hundred seventy patients with AVMs were included, with a mean age of 35 ± 19.6 years, with 61% white, 22% black, 3% Hispanic, 2% Asian, and 11% other ethnic groups. Nine of the female patients experienced AVM rupture during pregnancy or puerperium. Mean age at AVM rupture was 29.7 years and the mean AVM size was 3.2 cm. Overall, the annual hemorrhage rate for 149 total hemorrhages during an average of 11,097 patient years was 1.34%. There were 140 hemorrhages in nonexposed women and nine hemorrhages in pregnant women, translating to an annual hemorrhage rate of 1.3% in nonpregnant women vs. 5.7% in pregnant women (P < 0.001). These results remain controversial and contradict other studies recently published, and this difference may be related to the technique used for calculation as well as case ascertainment. Currently, the true risk of AVM hemorrhage during pregnancy is uncertain.