Table 2: Distribution of maternal characteristics by BPD status.

CharacteristicsAll infantsBPD
CasesControls 𝑃 OR* 95% CI
𝑛 = 2 1 2 𝑛 = 6 4 𝑛 = 1 4 8

Maternal characteristics
Mean age, 𝑛 (%)
 <18 years15 (7.1)5 (7.8)10 (6.8)1.080.383.08
 18–35 years173 (81.6)52 (81.3)121 (81.8)0.9591.00
 >35 years24 (11.3)7 (10.9)17 (11.5)0.970.501.88
Type of delivery, 𝑛 (%)
 Vaginal35 (16.5)12 (18.8)23 (15.5)0.5631.00
 Cesarean177 (83.5)52 (81.3)125 (84.5)0.860.511.43
Multiple gestation 𝑛 (%)22 (10.4)6 (9.4)16 (10.8)0.7530.890.441.83
Antenatal steroids, 𝑛 (%)184 (86.8)56 (87.5)128 (86.5)0.0721.320.632.75
PPROM, 𝑛 (%)76 (35.8)30 (46.9)46 (31.2)0.0281.581.062.36
Duration of rupture of membranes, 𝑛 (%)
 <24 h35 (46.1)12 (40.0)23 (50.0)0.2751.00
 24–48 h14 (18.4)5 (16.7)9 (19.6)0.760.144.02
 48–72 h8 (10.5)2 (6.7)6 (13.0)1.760.525.94
 >72 h19 (25.0)11 (36.7)8 (17.4)1.040.452.41
Chorio confirmed, 𝑛 (%)11 (5.2)4 (6.5)7 (4.7)0.6471.220.542.74
Chorio confirmed or suspected, 𝑛 (%)39 (18.4)17 (26.6)22 (14.9)0.0441.601.042.47

Chorio: chorioamnionitis, PPROM: preterm premature rupture of membranes.