Objective: To evaluate the efficacy and safety of carbetocin for prevention of postpartum hemorrhage in women undergoing vaginal delivery compared with oxytocin. Methods: We conducted a systemic literature search in PubMed, the Cochrane Library, and Embase without language restrictions from inception of each of database to November 18th, 2018. Randomized controlled trials with outcome measure of blood loss ≥500 ml were eligible if they compared carbetocin with oxytocin to prevent postpartum hemorrhage during the third stage of labor in women undergoing vaginal delivery. Results: This meta-analysis of 5 randomized controlled trials (30,314 women) indicated that there was no significant difference between carbetocin and oxytocin in blood loss ≥500 ml in women undergoing vaginal delivery (relative risks (RRs), 0.52; 95% confidence intervals (CIs), 0.24 to 1.15; P = .11; I 2 = 69%). Sensitivity analyses showed the same results. No significant differences were found in blood loss ≥1000 ml, use of additional uterotonic agents, blood transfusion, uterine massage, flushing, vomiting, abdominal pain, nausea, dizziness, headache, palpitation, itching, and shivering. Conclusions: This meta-analysis showed that carbetocin was as effective and safe as oxytocin for prevention of postpartum hemorrhage in women undergoing vaginal delivery, and the choice of carbetocin for routine prophylaxis will depend on cost-effectiveness.

To investigate the efficacy of cervical pessary placement in preventing preterm birth and perinatal morbidity and mortality in asymptomatic women with a singleton pregnancy and a short cervix, we searched literature in relevant databases. The meta-analysis of the 3 included trials (1412 women) showed cervical pessary placement did not reduce the risk of spontaneous preterm birth <34 weeks in these women (risk ratio (RR), 0.71; 95% confidence interval (CI), 0.21–2.43, P = 0.59; I2 = 90%). The sensitivity analyses by excluding one trial at one time showed the same results. This meta-analysis also showed that cervical pessary did not prevent preterm birth <34, 30, 28 weeks and was not associated with respiratory distress syndrome, necrotising enterocolitis, intraventricular haemorrhage, neonatal sepsis, retinopathy of prematurity, fetal death, neonatal death, perinatal death, birth weight <1500 g, birth weight <2500 g, premature preterm rupture of membranes, corticosteroid treatment for fetal maturation, and admission to neonatal intensive care unit. Although this meta-analysis showed cervical pessary placement did not reduce the risk of preterm birth in women with a singleton pregnancy and a short cervix, we could not confirm or refute this conclusion, and large-scale randomised controlled trials are urgently needed.