Table 2.

Gestational age at delivery and neonatal outcome in asymptomatic women with a singleton pregnancy and sonographic short cervix allocated to receive vaginal progesterone gel (n = 235) compared with those allocated to receive placebo (n = 223): intent to treat analysis set

Outcome	Vaginal progesterone (n (%))	Placebo (n (%))	Relative risk (95% CI)	P
Primary outcome
Preterm birth < 33 weeks	21/235 (8.9)	36/223 (16.1)	0.55 (0.33–0.92)	0.020
Secondary outcomes
Preterm birth < 28 weeks	12/235 (5.1)	23/223 (10.3)	0.50 (0.25–0.97)	0.036
Preterm birth < 35 weeks	34/235 (14.5)	52/223 (23.3)	0.62 (0.42–0.92)	0.016
Preterm birth < 37 weeks	71/235 (30.2)	76/223 (34.1)	0.89 (0.68–1.16)	0.376
Respiratory distress syndrome	7/235 (3.0)	17/223 (7.6)	0.39 (0.17–0.92)	0.026
Bronchopulmonary dysplasia	4/235 (1.7)	5/223 (2.2)	0.76 (0.21–2.79)	0.678
Proven sepsis	7/235 (3.0)	6/223 (2.7)	1.11 (0.38–3.24)	0.853
Necrotizing enterocolitis	5/235 (2.1)	4/223 (1.8)	1.19 (0.32–4.36)	0.797
Intraventricular hemorrhage, Grade III/IV	0/235 (0.0)	1/223 (0.5)	0.32 (0.01–7.73)*	0.305
Periventricular leukomalacia	0/235 (0.0)	0/223 (0.0)	Not estimable	NA
Perinatal death	8/235 (3.4)	11/223 (4.9)	0.69 (0.28–1.68)	0.413
Fetal death	5/235 (2.1)	6/223 (2.7)	0.79 (0.25–2.57)	0.700
Neonatal death	3/235 (1.3)	5/223 (2.2)	0.57 (0.14–2.35)	0.431
Composite outcome scores
Any morbidity/mortality event	18/235 (7.7)	30/223 (13.5)	0.57 (0.33–0.99)	0.043
0–4 without NICU†				0.048
0–4 with NICU†				0.068
0–6 without NICU†				0.048
Birth weight < 2500 g	60/234 (25.6)	68/220 (30.9)	0.83 (0.62–1.11)	0.213
Birth weight < 1500 g	15/234 (6.4)	30/220 (13.6)	0.47 (0.26–0.85)	0.010

Unadjusted relative risk (RR) and 95% CI calculated using the Cochran–Mantel–Haenszel (CMH) test.

^*Based on Logit estimator with continuity correction.

^†Frequency of perinatal mortality/neonatal morbidity composite scores are provided in Appendix S4 online. NA, not applicable; NICU, neonatal intensive care unit.