Table 4

Risk factors possibly contributing to failure of IR, unadjusted ORs (95% CI) for failed IR per risk factor

Risk factorsNumber of womenUnadjusted OR (95% CI) for failed IR
Failed IR, n=12 n, %Successful IR, n=87 n, %
Demographic factors
 Maternal age ≥35 years5 (41.7)33 (37.9)1.1 (0.3 to 3.9)
 BMI at booking ≥30 kg/m22 (18.2) 3 (3.9)5.6 (0.8 to 37.6)
Obstetric factors
 Twins1 (8.3) 6 (6.9)1.2 (0.1 to 11.1)
 Preterm gestational age <37 weeks
 Preterm gestational age <34 weeks
7 (58.3)
3 (25.0)
28 (32.2)
 6 (6.8)
2.9 (0.8 to 10.1)
4.5 (0.9 to 21.1)
 Parity ≥33 (25.0) 8 (9.2)3.2 (0.7 to14.6)
 Previous caesarean delivery7 (58.3)21 (24.1)4.4 (1.2 to 15.3)*
 Caesarean delivery (≥22 weeks)8 (72.7)42 (48.3)2.1 (0.6 to 7.6)
 Induction of labour
 Augmentation of labour
3 (25.0)
2 (16.7)
25 (28.7)
26 (29.9)
0.8 (0.2 to 3.3)
0. (0.09 to 2.2)
Cause of haemorrhage
 Atony7 (63.6)52 (62.7)0.9 (0.2 to 3.2)
  AIP and AIP+praevia7 (58.3)14 (16.1)7.3 (2.0 to 26.3)*
 Surgical trauma2 (16.7) 6 (6.9)2.7 (0.4 to 15.2)
 Genital tract laceration1 (8.3)10 (11.5)0.7 (0.08 to 6.0)
First-line and second-line treatment
 Uterotonic agents8 (66.7)82 (94.3)0.1 (0.02 to 0.5)*
 No use of uterotonic agents4 (33.3) 5 (5.7)8.2 (1.8 to 36.8)*
 Intra-uterine balloon3 (25.0)26 (29.9)0.7 (0.1 to 3.1)
 Clotting factors IV2 (16.7) 8 (9.2)1.9 (0.3 to 10.6)
 FFP7 (58.3)54 (62.1)0.8 (0.2 to 2.9)
Organisational factors
 Planned intervention2 (14)10 (12)1.5 (0.3 to 8.0)
 Weekend and/or non-office hours†5/10 (50.0)51/85 (60.0)0.6 (0.1 to 2.4)
 IR NOT available‡3 (25.0)10 (11.4)2.5 (0.6 to 11.1)
 Emergency IR NOT available‡6 (50.0)20 (22.9)3.3 (0.9 to 11.5)
 Postnatal transfer3 (25.0)13 (14.9)1.9 (0.4 to 7.9)
  • *p<0.05.

  • †Based on date and time of delivery.

  • ‡IR service availability (24/7 and not 24/7) in the maternity unit where the woman gave birth.

  • ‡Emergency IR service availability (24/7) in the maternity unit where the woman gave birth.

  • AIP, abnormally invasive placenta; BMI, body mass index; FFP, fresh frozen plasma; IR, interventional radiology.