TABLE 2.
Effect of vaginal progesterone on pregnancy, maternal, and perinatal outcomes
| Outcome | No of trials | Vaginal progesterone | Placebo/no treatment | Relative risk (95% CI) | P value | I2, % | 95% Prediction interval for the RR |
|---|---|---|---|---|---|---|---|
| Preterm birth <28 weeks | 972–74,76–81 | 62/1429 (4.3%) | 56/1406 (4.0%) | 1.12 (0.70–1.78) | 0.64 | 18 | 0.51–2.49 |
| Threatened preterm labor or need for tocolysis | 572–74,76,80 | 176/866 (20.3%) | 196/845 (23.2%) | 0.82 (0.63–1.06) | 0.12 | 37 | 0.48–1.42 |
| Use of antenatal corticosteroids | 273,80 | 211/699 (30.2%) | 213/687 (31.0) | 0.98 (0.83–1.14) | 0.76 | 0 | NA |
| Cesarean delivery | 373,74,80 | 215/749 (28.7%) | 191/737 (25.9%) | 1.11 (0.94–1.31) | 0.21 | 0 | NA |
| Any maternal adverse event | 373,76,80 | 385/740 (52.0%) | 369/718 (51.4%) | 1.01 (0.89–1.15) | 0.88 | 41 | NA |
| Discontinuation of treatment because of adverse events | 473,74,76,80 | 44/790 (5.6%) | 31/768 (4.0%) | 1.38 (0.88–2.14) | 0.16 | 0 | NA |
| Preterm prelabor rupture of membranes | 473,74,76,80 | 88/794 (11.1%) | 85/775 (11.0%) | 1.02 (0.77–1.35) | 0.87 | 0 | NA |
| Preeclampsia | 274,80 | 12/440 (2.7%) | 8/435 (1.8%) | 1.48 (0.61–3.58) | 0.38 | NA | NA |
| Gestational hypertension | 274,80 | 6/440 (1.4%) | 5/435 (1.2) | 1.19 (0.37–3.85) | 0.78 | 0 | NA |
| Gestational diabetes mellitus | 274,80 | 45/440 (10.2%) | 40/435 (9.2%) | 1.12 (0.75–1.67) | 0.59 | 0 | NA |
| Respiratory distress syndrome | 673–76,80,81 | 84/896 (9.4%) | 114/883 (12.9%) | 0.62 (0.37–1.04) | 0.07 | 57 | 0.18–2.13 |
| Necrotizing enterocolitis | 473,74,76,80 | 5/782 (0.6%) | 8/766 (1.0%) | 0.64 (0.22–1.90) | 0.42 | 0 | NA |
| Intraventricular hemorrhage | 473,75,76,80 | 17/801 (2.1%) | 15/788 (1.9%) | 1.11 (0.56–2.22) | 0.76 | 0 | NA |
| Grade III/IV intraventricular hemorrhage | 473,74,76,80 | 2/782 (0.3) | 2/766 (0.3) | 0.98 (0.14–6.94) | 0.98 | 0 | NA |
| Neonatal sepsis | 573–76,80 | 15/827 (1.8%) | 22/825 (2.7%) | 0.69 (0.29–1.68) | 0.42 | 26 | 0.14–3.32 |
| Retinopathy of prematurity | 276,80 | 12/422 (2.8%) | 9/414 (2.2%) | 1.32 (0.56–3.09) | 0.53 | NA | NA |
| Bronchopulmonary dysplasia | 374,76,80 | 10/473 (2.1%) | 5/464 (1.1%) | 1.97 (0.68–5.71) | 0.21 | NA | NA |
| Periventricular leukomalacia | 276,80 | 0/423 (0.0) | 1/414 (0.2) | 0.33 (0.01–8.03) | 0.49 | NA | NA |
| Fetal death | 673,74,76,78–80 | 16/1271 (1.3%) | 15/1251 (1.2%) | 1.05 (0.52–2.13) | 0.89 | 0 | 0.52–2.13 |
| Neonatal death | 773–76,78–80 | 20/1340 (1.5%) | 32/1323 (2.4%) | 0.65 (0.36–1.15) | 0.14 | 0 | 0.36–1.15 |
| Perinatal death | 673,74,76,78–80 | 33/1271 (2.6%) | 37/1251 (3.0%) | 0.90 (0.56–1.45) | 0.67 | 0 | 0.56–1.45 |
| Birthweight <1500 g | 473,74,76,80 | 55/781 (7.0%) | 42/762 (5.5%) | 1.28 (0.87–1.89) | 0.21 | 0 | NA |
| Birthweight <2500 g | 573–76,80 | 206/850 (24.2%) | 229/834 (27.5%) | 0.77 (0.54–1.10) | 0.15 | 64 | 0.33–1.82 |
| Admission to NICU | 673,74,75,76,80,81 | 129/896 (14.4%) | 183/883 (20.7%) | 0.53 (0.33–0.85) | 0.01 | 67 | 0.16–1.79 |
| Use of mechanical ventilation | 573–76,80 | 78/825 (9.5%) | 104/825 (12.6%) | 0.65 (0.39–1.08) | 0.10 | 44 | 0.21–2.00 |
| Patent ductus arteriosus | 373,74,80 | 18/721 (2.5%) | 15/718 (2.1%) | 1.19 (0.61–2.36) | 0.61 | 0 | NA |
Data are n/N.
CI, confidence interval; NA, not applicable; NICU, neonatal intensive care unit; RR, relative risk.