Table 1

Maternal and neonatal characteristics among study groups

No-PPROM (n=3400)Late-PPROM (n=829)Early-PPROM (n=225)
n (%)n (%)OR (95% CI)/mean difference†n (%)OR (95% CI)/mean difference†
Caucasian ethnicity2655 (78.1)658 (79.4)1.08 (0.89 to 1.30)186 (82.7)1.33 (0.94 to 1.91)
Maternal age, years‡29.9 (6.18)30.5 (6.07)0.569*29.7 (6.65)−0.253
Multiple pregnancy1001 (29.4)245 (29.5)1.00 (0.85 to 1.18)46 (20.4)0.61 (0.44 to 0.85)
Chorioamnionitis§480 (14.1)341 (41.1)4.25 (3.59 to 5.03)110 (48.9)5.81 (4.40 to 7.68)
Maternal antibiotics1403 (41.3)675 (81.4)6.23 (5.17 to 7.52)175 (77.8)4.98 (3.61 to 6.87)
Antepartum haemorrhage906 (26.6)128 (15.4)0.50 (0.41 to 0.61)75 (33.3)1.37 (1.03 to 1.83)
Preterm labour2143 (63)661 (79.7)2.30 (1.92 to 2.77)172 (76.4)1.90 (1.38 to 2.61)
Hypertensive disease of pregnancy807 (23.7)33 (4)0.13 (0.09 to  0.19)9 (4)0.13 (0.06 to 0.26)
Latency period >14 days70 (8.4)151 (67.1)
Antenatal steroids2995 (88)803 (97)4.17 (2.78 to 6.25)213 (95)2.4 (1.33 to 4.33)
GA at PPROM28.14 (26.2–29.5)22.14 (19.3–23)
Duration of PPROM hours¶76 (23–172)630 (205.5–1239)
GA at birth, weeks‡28.6 (2.15)29.09 (1.82)0.49***26.4 (2.28)−2.28***
Male1794 (52.8)423 (51)138 (61)1.42 (1.07 to 1.87)
Birth weight, g‡1246.9 (395.68)1367.4 (334.05)120.4***965.8 (333.02)−281.09***
Birth weight <10th percentile306 (9)10 (1.2)0.12 (0.06 to  0.23)7 (3.1)0.32 (0.15 to 0.69)
5 min Apgar‡7.6 (1.81)7.9 (1.51)0.36***6.5 (2.12)−1.04***
Worst BD, first 12 hours‡−2.47 (6.74)−2.31 (5.12)−0.15−2.28 (10.1)−0.19
  • Data presented as numbers (%), OR (95% CI) unless indicated otherwise.

  • *P<0.05; **P<0.01; ***P<0.001.

  • †In comparison to No-PPROM group.

  • ‡Mean (SD).

  • §Clinical and/or histological chorioamnionitis.

  • ¶Median (IQR).

  • BD, base deficit; GA, gestational age; PPROM, prelabour preterm rupture of membranes.