A meta-analysis 3 included 6 RCTs encompassing data from 787 patients (n = 390 for nifedipine; n = 397 for placebo/no treatment). There was no difference between the groups for the incidence of perinatal death (RR 1.36; 95% CI 0.35 to 5.33), intraventricular haemorrhage (IVH) ≥ grade II (RR 0.65; 95% CI 0.16 to 2.67), necrotising enterocolitis (NEC) (RR 1.15; 95% CI 0.50 to 2.65), infant respiratory distress syndrome (IRDS) (RR 0.98; 95% CI 0.51 to 1.85), and prolongation of pregnancy (hazard ratio, HR 0.74; 95% CI 0.55 to 1.01).
A Cochrane review [Abstract] 1 included 6 studies with 794 subjects. No difference in the incidence of preterm birth (RR 0.97; 95% CI 0.87 to 1.09; 5 trials, n=681), birth within 48 hours of treatment (RR 0.46; 95% CI 0.07 to 3.00; 2 trials, n=128) or neonatal mortality (average RR 0.75; 95% CI 0.05 to 11.76; 2 trials, 133 infants) were found when calcium channel blocker (nifedipine) maintenance therapy was compared with placebo or no treatment. Women receiving nifedipine maintenance therapy were significantly more likely to have their pregnancy prolonged (mean difference (MD) 5.35 days; 95% CI 0.49 to 10.21; four trials, 275 women); however, no differences between groups were shown for birth at less than 34 weeks' gestation, birth at less than 28 weeks' gestation, birth within seven days of treatment, or gestational age at birth.
A Cochrane review 2 included 1 study with a total of 513 subjects. When compared with placebo, atosiban did not reduce preterm birth before 37 weeks (RR 0.89; 95% CI 0.71 to 1.12), 32 weeks (RR 0.85; 95% CI 0.47 to 1.55), or 28 weeks (RR 0.75; 95% CI 0.28 to 2.01). No difference was shown in neonatal morbidity, or perinatal mortality.
Comment: The quality of evidence is downgraded by study quality (unclear blinding, possible selective outcome reporting bias).
Primary/Secondary Keywords