Route of Delivery as a Risk Factor for Emergent Peripartum Hysterectomy: A Case–Control Study Jennifer Kacmar, MD, Lisa Bhimani, MD, Mary Boyd, MD, Reza Shah-Hosseini, MD, and Jeffrey F. Peipert, MD, MPH OBJECTIVE: To evaluate whether cesarean delivery is a risk factor for emergent postpartum hysterectomy. METHODS: We performed a case– control study of patients who delivered at Women & Infants Hospital between Jan- uary 1989 and February 2000. Fifty cases of emergent postpartum hysterectomy performed within 14 days of delivery met our inclusion criteria. Using a computer- generated list, two patients admitted to the labor depart- ment at a time point similar to that of each case patient were selected as controls (n  100). We reviewed medical records for demographic data, route of delivery, labor characteristics, surgical history, and indication for hyster- ectomy. Cases and controls were compared, and logistic regression was used to calculate the odds ratio (OR) and the 95% confidence interval (CI) for the association of delivery route and emergent hysterectomy. RESULTS: Cesarean delivery was associated with a 13-fold increased risk of emergent hysterectomy when we con- trolled for previous cesarean delivery, dilation and curet- tage or abortion before the index pregnancy, use of prosta- glandin, and use of pitocin (OR 12.9; 95% CI 5.2, 32.3). CONCLUSION: Cesarean delivery is a significant risk factor for postpartum hysterectomy. (Obstet Gynecol 2003;102: 141–5. © 2003 by The American College of Obstetricians and Gynecologists.) In an effort to determine incidence, risk factors, and degree of morbidity, many case series of peripartum hysterectomy have been reported. Over time, the inci- dence has remained low (less than 0.6%). 1–7 Most cur- rent case series report an incidence of 0.1– 0.3%. 8 –13 Indications for peripartum hysterectomy have also evolved in response to the advent of improved antibiotic treatments, blood-banking techniques, and uterotonic agents. Although uncontrollable hemorrhage and infec- tion were once considered the principal risk factors, 1–3,14 abnormal placentation is now cited by the majority of modern reviews as the major risk factor for peripartum hysterectomy. 1,6,8,9,11–14 Intraoperative complication rates range from 10% to 36%, whereas postoperative complication rates are reportedly as high as 65%. 1– 6,8 –15 Countries with low rates of cesarean delivery also have remarkably lower rates of postpartum hysterec- tomy than the United States. In Norway, for example, Engelsen et al report an incidence of 0.2 per 1000 deliv- eries. 16 Two case series have suggested that cesarean delivery alone may be a risk factor for emergent peripar- tum hysterectomy. 9,13 However, these reports analyzed all patients who underwent hysterectomy, usually after cesarean delivery. For many of these patients, cesarean delivery was unavoidable because of abnormal placenta- tion (usually placenta previa). In fact, no report has addressed patients who labored before hysterectomy as a separate group. Including patients for whom vaginal delivery is not possible may obscure potentially prevent- able or, at least, predictable obstetric risk factors. Our objective was to elucidate risk factors for emergent post- partum hysterectomy. More specifically, this study was designed to test the hypothesis that the risk of emergent peripartum hysterectomy is increased after cesarean de- livery compared with vaginal delivery. MATERIALS AND METHODS Our study was performed in two stages. Approval was obtained from our institutional review board before each phase of the study. We first reviewed all cases performed at Women & Infants Hospital between 1983 and 1998 to evaluate the incidence and indications for emergent pe- ripartum hysterectomy at our institution. This case se- ries review provided 79 potential cases. Because our initial case series did not include a control group, we decided to perform a case– control study to assess potentially modifiable risk factors for hysterec- tomy after delivery. For ease of chart access, the study was confined to patients delivering during or after 1989. To augment our data, cases occurring in the 2 years after From Women & Infants Hospital, Providence, Rhode Island. Supported in part by National Institutes of Health grant K24 HD01298-03, Mid-career Investigator Award in Women’s Health Research (JFP) from the National Institute of Child Health and Human Development. 141 VOL. 102, NO. 1, JULY 2003 0029-7844/03/$30.00 © 2003 by The American College of Obstetricians and Gynecologists. Published by Elsevier. doi:10.1016/S0029-7844(03)00404-6