A Cochrane review [Abstract] 1 included 5 studies with a total of 507 subjects. Knowledge of transvaginal ultrasound (TVU) of cervical length (CL) was associated with a non-significant decrease in preterm birth (PTB) at less than 37 weeks compared to no knowledge of TVU (22.3% vs 34.7%, respectively; RR 0.59, 95% CI 0.26 to 1.32; 2 trials of singleton gestations, n=242). Delivery occurred at a later gestational age in the knowledge vs no knowledge groups (mean difference 0.64 weeks, 95% CI 0.03 to 1.25; 3 trials, n=290). All other outcomes (PTB at less than 34 or 28 weeks; birthweight less than 2500 grams; perinatal death; maternal hospitalization; tocolysis; and steroids for fetal lung maturity) were similar in the two groups. One trial of singleton gestations with preterm prelabour rupture of membranes evaluated as its primary outcome safety of TVU CL, and not its effect on management. The incidence of maternal and neonatal infections was similar in the groups. In the trial of twin gestations (n = 125), with or without preterm labour, there were no difference in PTB, gestational age, and other perinatal and maternal outcomes between the groups.
Comment: The quality of evidence is downgraded by study quality (several shortcomings in some studies, lack of blinding), by imprecise results (limited study size for each comparison).
Primary/Secondary Keywords