Table 2 Randomised placebo-controlled studies: Progesterone for the prevention of preterm birth in women with singleton pregnancies and a previous preterm birth.
| Author | Year | Number of patients (progesterone vs. control) | Inclusion criteria | Progestogen type | Dose and interval | Period of use (WG) | Primary outcome | Reduction in preterm birth |
|---|---|---|---|---|---|---|---|---|
| WG: weeks of gestation, 17-OHPC: 17α-hydroxyprogesterone caproate, PB: preterm birth, sPB: spontaneous preterm birth, a combination of neonatal death, brain damage or bronchopulmonary malformation, b secondary outcome | ||||||||
| A) 17α-OHPC | ||||||||
| Meis et al. 51 | 2003 | 310 vs. 153 | Previous sPB | i. m. 17α-OHPC | 250 mg/week | 16 – 20 to 36 | PB < 37 WG: 36.3 vs. 54.9% (p < 0.001) | Yes |
| B) Vaginal progesterone | ||||||||
| Fonseca et al. 60 | 2003 | 72 vs. 70 | Previous sPB, uterine anomalies, cervical incompetence | Vaginal pessaries | 100 mg/day | 24 to 34 | PB < 37 WG: 13.8 vs. 28.5% (p < 0.030) | Yes |
| OʼBrien et al. 14 | 2007 | 309 vs. 302 | Previous sPB | Vaginal gel | 90 mg/day | 18 – 24 to 36 | PB < 32 WG: 10 vs. 11.3% (p > 0.050) | No |
| Cetingoz et al. 33 | 2011 | 80 vs. 70 | Previous sPB, uterine anomalies (n = 67, twin pregnancies) | Vaginal pessaries | 100 mg/day | 24 to 34 | PB < 37 WG: 40 vs. 57.2% (p < 0.036) | Yes |
| Azargoon et al. 61 | 2016 | 50 vs. 50 | Previous PB, uterine anomalies, intramural fibroid ≥ 7 cm | Vaginal pessaries | 400 mg/day | 16 – 22 to 36 | PB < 37 WG: 36 vs. 68% (p < 0.001) | Yes |
| Norman et al. 16 | 2016 | 610 vs. 618 | Previous sPB, cervical length ≤ 25 mm, pos. fetal fibronectin combined with other PB risk factor | Vaginal pessaries | 200 mg/day | 22 – 24 to 34 | PB or fetal death < 34 WG: 16 vs. 18% (p = 0.670) Neonatal outcome a : 7 vs. 10% (p = 0.072) Cognitive score [at 2 y]: 17.9 vs. 17.5% (p = 0.680) |
No |
| Crowther et al. 15 | 2017 | 398 vs. 389 | Previous sPB (n = 12, twin pregnancies) | Vaginal pessaries | 100 mg/day | 18 – 24 to 34 | Acute respiratory distress syndrome: 10.5 vs. 10.6% (p = 0.905) Severity: no difference (p = 0.905) PB < 37 WG b : 36.5 vs. 37.2% (p = 0.765) |
No |
| C) Oral progesterone | ||||||||
| Rai et al. 62 | 2009 | 74 vs. 74 | Previous sPB | Oral | 200 mg/day | 18 – 24 to 36 | PB < 37 WG: 39.2 vs. 59.5% (p = 0.002) | Yes |
| Glover et al. 63 | 2011 | 19 vs. 14 | Previous sPB | Oral | 400 mg/day | 16 – 20 to 33 | PB < 37 WG: 26.3 vs. 57.1% (p = 0.150) | Yes |
| Ashoush et al. 17 | 2017 | 106 vs. 106 | Previous sPB | Oral | 400 mg/day | 14 – 18 to 37 | PB < 37 WG: 44.7 vs. 63.7% (p = 0.010) | Yes |