Table 3

Demographic and clinical variables of infants with moderate or severe hypoxic-ischaemic encephalopathy born in level 2 centres post propensity score-matching

VariablesUnmatched infantsPropensity score matched infants
Born in non-CCBorn in CCSMDP value†Born in non-CCBorn in CCSMDP value†
n=1546*n=701*n=696*n=696*
Gender (male)877 (56.7)373 (53.2)−0.070.12366 (52.6)373 (53.6)0.020.71
Birth weight (g)3332 (2929–3760)3370 (2960–3730)−0.0330.423372 (3004–3764)3370 (2953–3730)0.0360.5
Gestation (weeks)40 (38–41)40 (38–41)−0.0470.2840 (39–41)40 (38–41)0.0320.56
Birth year2014 (2012–2015)2014 (2012–2015)−0.1340.0032014 (2013–2015)2014 (2012–2015)0.010.86
Pre-eclampsia71 (4.6)38 (5.4)−0.040.431 (4.5)38 (5.5)−0.0460.39
Maternal Infection383 (24.8)173 (24.7)0.0020.96176 (25.3)172 (24.7)0.0130.8
Mode of delivery‡:
 Em CS no labour263 (17.0)118 (16.8)0.0050.92115 (16.5)118 (17.0)−0.0120.83
 Em CS in labour494 (32.0)205 (29.2)0.0590.2200 (28.7)205 (29.5)−0.0160.77
 El CS no labour13 (0.8)7 (1.0)−0.0170.717 (1.0)6 (0.9)0.0150.78
 El CS in labour6 (0.4)3 (0.4)−0.0060.894 (0.6)3 (0.4)0.020.71
 Instrumental240 (15.5)144 (20.5)−0.1310.003137 (19.7)140 (20.1)−0.0110.84
 Missing57 (3.7)19 (2.7)0.0550.2428 (4.0)19 (2.7)0.0720.18
Presentation:
 Cephalic1231 (79.6)586 (83.6)−0.1030.03588 (84.5)582 (83.6)0.0240.66
 Breech84 (5.4)42 (6.0)−0.0240.5934 (4.9)41 (5.9)−0.0440.41
 Transverse lie10 (0.7)4 (0.6)0.010.834 (0.6)4 (0.6)01
 Other11 (0.7)5 (0.7)013 (0.4)5 (0.7)−0.0380.48
 Missing210 (13.6)64 (9.1)0.1410.00367 (9.6)64 (9.2)0.0150.78
Intra-partum events187 (12.1)89 (12.7)−0.0180.6993 (13.4)89 (12.8)0.0170.75
Significant resuscitation935 (60.50434 (61.9)−0.0290.52440 (63.2)432 (62.1)0.0230.66
Apgar at 5 min4 (2–5)4 (2–6)−0.070.094 (3–6)4 (2–6)0.0180.74
Grade of HIE
 Grade 2521 (33.7)243 (34.7)0.020.66236 (33.9)240 (34.5)0.0120.82
 Grade 31025 (66.3)458 (65.3)460 (66.1)456 (65.5)
  • *Data are n (%) or median (interquartile).

  • †Categorical data analysed using χ² test; non-normally distributed continuous data analysed using Mann-Whitney U test; matched data by paired t-test for continuous data or McNemar’s test or extensions thereof for binary and categorical data.

  • ‡Compared with baseline − normal vaginal delivery.

  • CC, cooling centre; El CS, elective caesarean section; Em CS, emergency caesarean section; HIE, hypoxic-ischaemic encephalopathy; NVD, normal vaginal delivery; SMD, standardised mean difference.