BackgroundIn high-income countries, the incidence of severe postpartum hemorrhage (PPH) has increased. This has important public health relevance because severe PPH is a leading cause of major maternal morbidity. However, few studies have identified risk factors for severe PPH within a contemporary obstetric cohort.MethodsWe performed a case-control study to identify risk factors for severe PPH among a cohort of women who delivered at one of three hospitals in Norway between 2008 and 2011. A case (severe PPH) was classified by an estimated blood loss ≥1500 mL or the need for blood transfusion for excessive postpartum bleeding. Using logistic regression, we applied a pragmatic strategy to identify independent risk factors for severe PPH.ResultsAmong a total of 43,105 deliveries occurring between 2008 and 2011, we identified 1064 cases and 2059 random controls. The frequency of severe PPH was 2.5% (95% confidence interval (CI): 2.32–2.62). The most common etiologies for severe PPH were uterine atony (60%) and placental complications (36%). The strongest risk factors were a history of severe PPH (adjusted OR (aOR) = 8.97, 95% CI: 5.25–15.33), anticoagulant medication (aOR = 4.79, 95% CI: 2.72–8.41), anemia at booking (aOR = 4.27, 95% CI: 2.79–6.54), severe pre-eclampsia or HELLP syndrome (aOR = 3.03, 95% CI: 1.74–5.27), uterine fibromas (aOR = 2.71, 95% CI: 1.69–4.35), multiple pregnancy (aOR = 2.11, 95% CI: 1.39–3.22) and assisted reproductive technologies (aOR = 1.88, 95% CI: 1.33–2.65).ConclusionsBased on our findings, women with a history of severe PPH are at highest risk of severe PPH. As well as other established clinical risk factors for PPH, a history of severe PPH should be included as a risk factor in the development and validation of prediction models for PPH.

Background Over the past two decades several high-income countries have reported increased rates of postpartum haemorrhage (PPH). Many of the studies are registry studies with limited access to detailed information. We aimed to explore trends of severe PPH in the largest labour ward in Norway during a 10-year period with a hospital based study. Our population constituted all women who gave birth after week 22 at Oslo University Hospital between 2008 and 2017. The main outcome measure was severe PPH, defined as registered blood loss greater than 1500 ml, or transfusion of blood products due to PPH. Methods We estimated the incidence of severe PPH and blood transfusions, and performed temporal trend analysis. We performed Poisson regression analysis to investigate associations between pregnancy characteristics and severe PPH, presented using crude incidence rate ratios (IRR) with 95% confidence intervals (CI)s. We also estimated annual percentage change of the linear trends. Results Among 96 313 deliveries during the 10-year study period, 2621 (2.7%) were diagnosed with severe PPH. The incidence rate doubled from 17.1/1000 to 2008 to 34.2/1000 in 2017. We also observed an increased rate of women receiving blood transfusion due to PPH, from 12.2/1000 to 2008 to 27.5/1000 in 2017. The rates of invasive procedures to manage severe PPH did not increase, and we did not observe a significant increase in the number of women defined with maternal near miss or massive transfusions. No women died due to PPH during the study period. Conclusion We found a significant increasing trend of severe PPH and related blood transfusions during the 10-year study period. We did not find an increase in massive PPH, or in invasive management, and we suspect that the rise can be at least partly explained by increased awareness and early intervention contributing to improved registration of severe PPH.

Introduction A peripartum hysterectomy is typically performed as a lifesaving procedure in obstetrics to manage severe postpartum hemorrhage. Severe hemorrhages that lead to peripartum hysterectomies are mainly caused by uterine atony and placenta accreta spectrum disorders. In this study, we aimed to estimate the incidence, risk factors, causes and management of severe postpartum hemorrhage resulting in peripartum hysterectomies, and to describe the complications of the hysterectomies. Material and methods Eligible women had given birth at gestational week 23+0 or later and had a postpartum hemorrhage ≥1500 mL or a blood transfusion, due to postpartum hemorrhage, at Oslo University Hospital, Norway, between 2008 and 2017. Among the eligible women, this study included those who underwent a hysterectomy within the first 42 days after delivery. The Norwegian Medical Birth Registry provided the reference group. We used Poisson regression to estimate adjusted incidence rate ratios with 95% confidence intervals to identify clinical factors associated with peripartum hysterectomy. Results The incidence of hysterectomies with severe postpartum hemorrhage was 0.44/1000 deliveries (42/96313). Among the women with severe postpartum hemorrhage, 1.6% ended up with a hysterectomy (42/2621). Maternal age ≥40, previous cesarean section, multiple pregnancy and placenta previa were associated with a significantly higher risk of hysterectomy. Placenta accreta spectrum disorders were the most frequent cause of hemorrhage that resulted in a hysterectomy (52%, 22/42) and contributed to most of the complications following the hysterectomy (11/15 women with complications). Conclusions The rate of peripartum hysterectomies at Oslo University Hospital was low, but was higher than previously reported from Norway. Risk factors included high maternal age, previous cesarean section, multiple pregnancy and placenta previa, well known risk factors for placenta accreta spectrum disorders and severe postpartum hemorrhage. Placenta accreta spectrum disorders were the largest contributor to hysterectomies and complications.