Go Red for Women The Risk of Aneurysmal Subarachnoid Hemorrhage During Pregnancy, Delivery, and the Puerperium in the Utrecht Population Case-Crossover Study and Standardized Incidence Ratio Estimation Andreas T. Tiel Groenestege, MSc; Gabriel J.E. Rinkel, MD; Johanna G. van der Bom, MD; Ale Algra, MD; Catharina J.M. Klijn, MD Background and Purpose—It is unclear whether the risk of aneurysmal subarachnoid hemorrhage (aSAH) is increased during pregnancy, labor, and the puerperium. We compared the risk of aSAH during this period with the risk outside this period. Methods—We included women with aSAH between 18 and 42 years of age (n=244) from our prospectively collected database of patients with subarachnoid hemorrhage treated in the University Medical Center Utrecht, the provincial referral center, between January 1987 and April 2006. We estimated the relative risk of aSAH during pregnancy, delivery, or the puerperium by a case-crossover design and calculated a standardized incidence ratio, dividing the observed number of patients with aSAH during pregnancy, delivery, or puerperium by the expected number based on the incidence in the general population of women of the same age during the study period. Results—Of the 244 women, 4 were pregnant, 3 in the puerperium and none in labor. The relative risk of aSAH during pregnancy, delivery, or the puerperium was 0.4 (95% CI, 0.2 to 0.9). Based on the number of women aged 18 to 42 years within the catchment area of our hospital and the number of pregnancies within the study period, the expected number of patients with aSAH during pregnancy, delivery, or the puerperium was 12, resulting in a standardized incidence ratio of 0.6 (95% CI, 0.2 to 1.1). Conclusions—The risk of aSAH is not increased during pregnancy, labor, and the puerperium. There is no need to advise against pregnancy in women with an increased risk of subarachnoid hemorrhage and no evidence to advise against vaginal delivery in such women. (Stroke. 2009;40:1148-1151.) Key Words: aneurysms  epidemiology  postpartum  pregnancy  SAH A neurysmal subarachnoid hemorrhage (aSAH) during pregnancy, delivery, and the puerperium is a serious condition for the mother and the unborn child. The reported maternal case-fatality from aSAH during pregnancy or the puerperium is comparable with the 50% case-fatality of subarachnoid hemorrhage (SAH) in general. 1,2 The fetal case-fatality is approximately 17%. 2 Maternal mortality in the Western world is approximately 10 per 100 000 deliveries. 3,4 Because the number of direct deaths (those related to com- plications directly related to the pregnant state) has fallen strikingly over the past decades, death from indirect causes has become increasingly important. 3,5,6 SAH may account for up to one of 10 of all maternal deaths in pregnant women and up to one of 4 maternal deaths from indirect causes. 3 The reported frequency of SAH in pregnant women and during the puerperium ranges from 8 to 31 per 100 000 deliveries. 7–11 The incidence of aSAH for women in general is 11.5 per 100 000 person-years and increases with age. 12 It remains unclear whether the risk of aSAH is increased during the period of pregnancy, delivery, and the puerperium. Some have suggested that the risk of SAH during pregnancy, delivery, or the puerperium is higher than outside this period, 13–15 whereas others concluded that rupture of an aneurysm is not more common during pregnancy than at other times. 16 An increased tendency of aSAH with advanc- ing gestational age has been suggested and related to the hemodynamic changes that occur during the course of pregnancy. 2,4,17 The purpose of this study was to assess whether the risk of aSAH is increased during pregnancy, delivery, or the puer- perium in comparison with the time that women are not pregnant, in delivery, or in the puerperium. Received October 9, 2008; final revision received December 15, 2008; accepted January 14, 2009. From the Department of Neurology (A.T.T.G., G.J.E.R., A.A., C.J.M.K.), Rudolf Magnus Institute of Neuroscience, Utrecht, The Netherlands; the Department of Clinical Epidemiology (A.A.), Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands; and the Department of Clinical Epidemiology (J.G.v.d.B., A.A.), Leiden University Medical Center, Leiden, The Netherlands. Correspondence to Catharina J.M. Klijn, MD, Department of Neurology, G03.225, University Medical Center Utrecht, PO Box 85500, 3508 GA Utrecht, The Netherlands. E-mail c.j.m.klijn@umcutrecht.nl © 2009 American Heart Association, Inc. Stroke is available at http://stroke.ahajournals.org DOI: 10.1161/STROKEAHA.108.539700 1148 Downloaded from http://ahajournals.org by on January 16, 2022