Table 2.
Effect of vaginal progesterone on the risk of preterm birth and adverse perinatal outcomes
| Outcome | Trials (n refs) | Events (n) Total(N) | Pooled RR (95% CI) | I 2 (%) | NNT (95% CI) | |
|---|---|---|---|---|---|---|
| Vaginal progesterone | Placebo | |||||
| Primary outcome | ||||||
| Preterm birth ≤ 34 weeks or fetal death | 544, 48, 49, 50, 51 | 90/498 | 131/476 | 0.66 (0.52–0.83) | 0 | 11 (8–21) |
| Secondary outcome | ||||||
| Preterm birth < 34 weeks | 448, 49, 50, 51 | 53/365 | 88/358 | 0.60 (0.44–0.82) | 0 | 10 (7–23) |
| Spontaneous preterm birth < 34 weeks | 448, 49, 50, 51 | 43/365 | 69/358 | 0.63 (0.44–0.88) | 0 | 14 (9–43) |
| Preterm birth < 37 weeks | 448, 49, 50, 51 | 127/365 | 141/358 | 0.89 (0.74–1.08) | 0 | — |
| Preterm birth < 36 weeks | 448, 49, 50, 51 | 93/365 | 117/358 | 0.79 (0.63–0.99) | 0 | 15 (8–306) |
| Preterm birth < 35 weeks | 448, 49, 50, 51 | 67/365 | 100/358 | 0.67 (0.51–0.87) | 0 | 11 (7–28) |
| Preterm birth < 33 weeks | 448, 49, 50, 51 | 41/365 | 72/358 | 0.56 (0.40–0.80) | 0 | 11 (8–25) |
| Preterm birth < 32 weeks | 448, 49, 50, 51 | 35/365 | 62/358 | 0.56 (0.38–0.82) | 0 | 13 (9–32) |
| Preterm birth < 30 weeks | 448, 49, 50, 51 | 27/365 | 46/358 | 0.59 (0.37–0.92) | 0 | 19 (12–97) |
| Preterm birth < 28 weeks | 448, 49, 50, 51 | 20/365 | 39/358 | 0.51 (0.31–0.85) | 0 | 19 (13–61) |
| Respiratory distress syndrome | 448, 49, 50, 51 | 17/365 | 37/358 | 0.47 (0.27–0.81) | 0 | 18 (13–51) |
| Necrotizing enterocolitis | 448, 49, 50, 51 | 5/365 | 6/358 | 0.88 (0.29–2.62) | 0 | — |
| Intraventricular hemorrhage | 448, 49, 50, 51 | 5/365 | 7/358 | 0.68 (0.22–2.13) | 0 | — |
| Proven neonatal sepsis | 448, 49, 50, 51 | 11/365 | 14/358 | 0.80 (0.37–1.74) | 0 | — |
| Retinopathy of prematurity | 448, 49, 50, 51 | 5/365 | 3/358 | 1.51 (0.40–5.69) | 0 | — |
| Fetal death | 448, 49, 50, 51 | 6/365 | 7/358 | 0.82 (0.28–2.40) | 0 | — |
| Neonatal death | 448, 49, 50, 51 | 6/365 | 11/358 | 0.53 (0.20–1.39) | 0 | — |
| Perinatal death | 448, 49, 50, 51 | 12/365 | 18/358 | 0.64 (0.31–1.31) | 0 | — |
| Composite neonatal morbidity/mortality* | 448, 49, 50, 51 | 29/365 | 49/358 | 0.59 (0.38–0.91) | 0 | 18 (12–81) |
| Birth weight < 1500 g | 448, 49, 50, 51 | 28/364 | 53/355 | 0.52 (0.34–0.81) | 0 | 14 (10–35) |
| Birth weight < 2500 g | 448, 49, 50, 51 | 102/364 | 117/355 | 0.86 (0.69–1.07) | 0 | — |
| Admission to NICU | 448, 49, 50, 51 | 59/365 | 87/358 | 0.67 (0.50–0.91) | 0 | 12 (8–46) |
| Mechanical ventilation | 448, 49, 50, 51 | 28/365 | 43/358 | 0.65 (0.41–1.01) | 0 | — |
*
Occurrence of any of the following events: respiratory distress syndrome; intraventricular hemorrhage; necrotizing enterocolitis; proven neonatal sepsis; neonatal death.
CI, confidence interval; NICU, neonatal intensive care unit; NNT, number needed to treat; RR, relative risk.