Chief Scientist Office of the Scottish Government Health Directorate.

ObjectiveTo quantify reporting errors, measure incidence of postpartum haemorrhage (PPH) and define risk factors for PPH (≥500 ml) and progression to severe PPH (≥1500 ml).DesignProspective observational study.SettingTwo UK maternity services.PopulationWomen giving birth between 1 August 2008 and 31 July 2009 (n = 10 213).MethodsWeighted sampling with sequential adjustment by multivariate analysis.Main outcome measuresIncidence and risk factors for PPH and progression to severe PPH.ResultsErrors in transcribing blood volume were frequent (14%) with evidence of threshold preference and avoidance. The incidences of PPH ≥500, ≥1500 and ≥2500 ml were 33.7% (95% CI 31.2–36.2), 3.9% (95% CI 3.3–4.6) and 0.8% (95% CI 0.6–1.0). New independent risk factors predicting PPH ≥ 500 ml included Black African ethnicity (adjusted odds ratio [aOR] 1.77, 95% CI 1.31–2.39) and assisted conception (aOR 2.93, 95% CI 1.30–6.59). Modelling demonstrated how prepregnancy- and pregnancy-acquired factors may be mediated through intrapartum events, including caesarean section, elective (aOR 24.4, 95% CI 5.53–108.00) or emergency (aOR 40.5, 95% CI 16.30–101.00), and retained placenta (aOR 21.3, 95% CI 8.31–54.7). New risk factors were identified for progression to severe PPH, including index of multiple deprivation (education, skills and training) (aOR 1.75, 95% CI 1.11–2.74), multiparity without caesarean section (aOR 1.65, 95% CI 1.20–2.28) and administration of steroids for fetal reasons (aOR 2.00, 95% CI 1.24–3.22).ConclusionsSequential, interacting, traditional and new risk factors explain the highest rates of PPH and severe PPH reported to date.

Key content The incidence of caesarean sections performed at full dilatation is increasing, and may now represent around 8000 deliveries in the UK each year. Delivery can be technically challenging due to fetal impaction into the pelvis, and may be associated with greater maternal and fetal morbidity even without failed attempt at vaginal delivery. Guidelines are needed to define optimal management, including the use of new devices to teach or assist safe delivery. Best practice should be incorporated into structured training programmes such as Managing Obstetric Emergencies and Trauma (MOET). Learning objectives Assess the reasons for the increasing incidence of full dilatation caesarean section at full dilatation. Describe the associated maternal and neonatal risks compared with operative vaginal delivery. Describe the current evidence for optimal management and define areas for research. Ethical issues Further research is needed to define long‐term morbidity and address the risk/benefit of second‐stage caesarean section at full dilatation versus attempted vaginal delivery.

BACKGROUND: Vaginal cerclage (a suture around the cervix) commonly is placed in women with recurrent pregnancy loss. These women may experience late miscarriage or extreme preterm delivery, despite being treated with cerclage. Transabdominal cerclage has been advocated after failed cerclage, although its efficacy is unproved by randomized controlled trial. OBJECTIVE: The objective of this study was to compare transabdominal cerclage or high vaginal cerclage with low vaginal cerclage in women with a history of failed cerclage. Our primary outcome was delivery at <32 completed weeks of pregnancy. STUDY DESIGN: This was a multicenter randomized controlled trial. Women were assigned randomly (1:1:1) to receive transabdominal cerclage, high vaginal cerclage, or low vaginal cerclage either before conception or at <14 weeks of gestation. RESULTS: The data for 111 of 139 women who were recruited and who conceived were analyzed: 39 had transabdominal cerclage; 39 had high vaginal cerclage, and 33 had low vaginal cerclage. Rates of preterm birth at <32 weeks of gestation were significantly lower in women who received transabdominal cerclage compared with low vaginal cerclage (8% [3/39] vs 33% [11/33]; relative risk, 0.23; 95% confidence interval, 0.07e0.76; P¼.0157). The number needed to treat to prevent 1 preterm birth was 3.9 (95% confidence interval, 2.32e12.1). There was no difference in preterm birth rates between high and low vaginal cerclage (38% [15/39] vs 33% [11/33]; relative risk, 1.15; 95% confidence interval, 0.62e2.16; P¼.81). No neonatal deaths occurred. In an exploratory analysis, women with transabdominal cerclage had fewer fetal losses compared with low vaginal cerclage (3% [1/39] vs 21% [7/33]; relative risk, 0.12; 95% confidence interval, 0.016e0.93; P¼.02). The number needed to treat to prevent 1 fetal loss was 5.3 (95% confidence interval, 2.9e26). CONCLUSION: Transabdominal cerclage is the treatment of choice for women with failed vaginal cerclage. It is superior to low vaginal cerclage in the reduction of risk of early preterm birth and fetal loss in women with previous failed vaginal cerclage. High vaginal cerclage does not confer this benefit. The numbers needed to treat are sufficiently low to justify transabdominal surgery and cesarean delivery required in this select cohort.