second injection of 500 mg over four hours) (Nalador; Schering, Lys-les-Lannoy, France). After obstetrical evaluation patients were transferred under close monitoring to the vascular imaging department for SAE. Resuscitation continued during SAE. The vascular radiologist performed emergency digital subtraction angiography with an unilateral femoral approach. In most cases contralateral internal iliac angiography and selective study of the anterior division then followed, always with a 5-F cobra catheter and a hydrophilic polymer-coated 0.032-inch guide wire (Radiofocus; Terumo) to analyse the uterine arteries. Super-selective study of the uterine artery was attempted in all cases. Other anastomotic vessels, including the vaginal, ovarian and round ligament arteries, were studied when necessary. The ipsilateral internal iliac artery was then catheterised by the same puncture site and the same cobra catheter. Absorbable gelatin sponge pledgets were injected as embolisation agents under fluoroscopic guidance. Bilateral embo- lisation was attempted in all patients. When the uterine artery could not be selectively catheterised, the anterior division of the hypogastric artery was embolised instead. Post-embolisation angiography was performed to verify the complete occlusion of the vessels. All patients were transferred to the surgical intensive care unit for at least 24 hours for further observation and coagulation studies with the femoral artery sheath left in place until achievement of haemodynamic stability, correction of coagulation disorders and complete cessation of the haemorrhage. In this study we considered SAE effective when bleeding stopped after the procedure. The embolisation was considered ineffective when any additional surgical procedure was necessary to stop the bleeding completely. Data extracted from the patients’ records included individual and obstetric characteristics (maternal age, parity, mode and term of delivery, cause of PPH), as well as those relevant to critical care, haemostasis and coagulation (shock, disseminated intravascular coagulation, mean haemoglobin level, mean platelet count, mean prothrombin time, mean partial thromboplastin time expressed as ratio to control values, mean number units of whole blood, fresh frozen plasma and platelets transfused). Ethics The French Research Ethics Committee chair stated that approval for this study was not required. Statistical methods Results are expressed as means6SE. We used univariate procedures (Student’s t test or chi-square test, as appropriate) to test possible associations of laboratory findings and clinical parameters with the embolisation results. We first analysed the relation between the patients’ characteristics (e.g., causes of PPH) and SAE results and then that between the critical care-related variables and SAE outcome. To estimate the independent predictive value of each variable, they were all analysed in a multivariate procedure with stepwise logistic regression (Biomed- ical Data Processing Package, University of California, Los Angeles, California). Conservative criteria were used to select variables (p value of 5% required for entry into or removal from model) and the ratio between the regression coefficient for each factor and its standard error had to exceed 2. Results During the study period 102 patients were treated with SAE and enrolled in the study: 12 (11.7%) gave birth in the obstetrics Arterial Embolisation department of our institution and 90 (88.3%) patients were transferred from other obstetrics units. Patients’ Characteristics Table 1 reports the women’s obstetrical characteristics. PPH was caused by uterine atony (N = 44, 43.1%), cervical or vaginal tears (N = 20, 19.6%), abnormal placentation (including placenta accreta and percreta) (N = 14, 13.6%), vaginal thrombus (N = 11, 10.7%), intrauterine retention (N = 7, 6.8%), abruptio placentae (N = 4, 3.9%) and repaired uterine rupture, (N = 2 , 1.9%). Overall, 46 (45%) patients had haemodynamic shock, and 59 (57.8%) disseminated intravascular coagulation. At admission, the mean haemoglobin level was 6.0361.6 dg/l (1.8–10.5), mean platelet count 81 698646 740 (28 000–240 000), mean prothrombin rate 42.7618.3 (5–90) and mean partial thrombo- plastin time (relative to control values) 2.1561.8 . The mean number of units of whole blood transfused was 8.666.3 (1–31), of fresh frozen plasma 3.564.3 (0–23) and of platelets 1.0263.5 (0– 14) respectively. Three women required emergency management of cardiac arrest. SAE of both uterine arteries was performed in 57 (55.8%) cases, SAE of one uterine artery and embolisation of the contralateral anterior branch of the hypogastric artery in 24 (23.5%), and bilateral embolisation of the anterior branch of the hypogastric artery in the other 21 (20.5%). Other vessels were embolised in six (5.8%) women: 4 (3.9%) the cervicovaginal arteries, and 1 each (0.8%) the ovarian anastomosis and the round ligament artery. Two women died during in this study. The first patient was 29 years old, gravida 7, para 3, with past medical history of pre- eclampsia (in 5 previous pregnancies) and intrauterine death (in 3). Caesarean delivery took place under general anaesthesia at 28 weeks’ gestation, for severe pre-eclampsia. She was transferred to our surgical intensive care unit, after C-section, for persistent diffuse bleeding. At admission, her haemoglobin level was 8.4 dg/ l, her platelet count 63 000, prothrombin rate 24%, and fibrinogen 35 mg/dl. Major shock followed, with bilateral mydriasis; haemoglobin dropped to 4.9 dg/l. She received 6 units of whole Table 1. Maternal and obstetrical characteristics of the patients. Mean6Standard Deviation Age Range Parity Range Range Mean6Standard Deviation Term of Delivery Mean6Standard Deviation Multiple pregnancies (twin) n (%) Mode of delivery Vaginal delivery n (%) - Forceps delivery n (%) Caesarean delivery n (%) Birth Weight Mean6Standard Deviation Range doi:10.1371/journal.pone.0003819.t001 31.8 years65.9 21–45 years 2.0161.11 1–6 38.362,9 weeks 28 to 42 weeks 4 (3.9%) 82 (79.4%) 28/81 (34.5%) 22 (20.6%) 3263.46546.6 2120–4751 PLoS ONE | www.plosone.org 3 November 2008 | Volume 3 | Issue 11 | e3819