To compare the efficacy of bed rest, cervical cerclage (McDonald, Shirodkar, or unspecified type of cerclage), cervical pessary, fish oils or omega fatty acids, nutritional supplements (zinc), progesterone (intramuscular, oral, or vaginal), prophylactic antibiotics, prophylactic tocolytics, combinations of interventions, placebo or no treatment (control) to prevent spontaneous preterm birth in women with a singleton pregnancy and a history of spontaneous preterm birth or short cervical length.
Systematic review with bayesian network metaanalysis.
The Cochrane Pregnancy and Childbirth Group’s Database of Trials, the Cochrane Central Register of Controlled Trials, Medline, Embase, CINAHL, relevant journals, conference proceedings, and registries of ongoing trials.
Criteria for selecting studies Randomised controlled trials of pregnant women who are at high risk of spontaneous preterm birth because of a history of spontaneous preterm birth or short cervical length. No language or date restrictions were applied.
Seven maternal outcomes and 11 fetal outcomes were analysed in line with published core outcomes for preterm birth research. Relative treatment effects (odds ratios and 95% credible intervals) and certainty of evidence are presented for outcomes of preterm birth <34 weeks and perinatal death.