Table 1

Personal characteristics of cohort, presented for whole cohort and according to expectant management or termination of pregnancy for medical reasons

CharacteristicsWhole cohort (n=364)Management groupComparison of management groups (P value)
Expectant (n=251)Termination for medical reasons (n=113)
Mean (SD) maternal age (years)32 (6)32 (6)33 (5)0.265
Maternal smoking at booking appointment81 (22)61 (24)20 (18)0.151
Maternal body mass index:
 <18.511 (3)9 (4)2 (2)0.805
 18.5-<25.0134 (37)95 (38)39 (35)
 25.0-<30.092 (25)59 (24)33 (29)
 30.0-<3556 (15)39 (16)17 (15)
 ≥35.051 (14)36 (14)15 (13)
 Not specified20 (5)13 (5)7 (6)
Maternal ethnic group:
 Asian62 (17)42 (17)20 (18)0.644
 Black35 (10)23 (9)12 (11)
 Mixed or any other ethnic group14 (4)10 (4)4 (4)
 White248 (68)171 (68)77 (68)
 Not specified5 (1)5 (2)0 (0)
Obstetric history:
 Primiparous155 (43)104 (41)51 (45)0.569
 At least one previous pregnancy affected by PPROM, mid-trimester loss, or preterm birth63 (17)40 (16)23 (20)0.303
Singleton pregnancy326 (90)223 (89)103 (91)0.506
Amniocentesis or chorionic villous sampling in pregnancy10 (3)6 (2)4 (4)0.535
Cervical cerclage before PPROM29 (8)22 (9)7 (6)0.402
Median (IQR) gestational age at PPROM (weeks+days)19+3 (17+6-21+1)19+6 (18+2-21+2)18+6 (17+2-20+2)0.000
  • Data are number (%) unless indicated otherwise. IQR=interquartile range; PPROM=preterm prelabour rupture of membranes; SD=standard deviation.