No ACS exposure Group 1: ACS < 34 weeks Group 2: ACS ≥ 34 weeks Group 2: ACS ≥ 34 weeks
all Group 2a: ACS within 7 days of planned delivery
n = 19772 n = 143 n = 187 n = 106
Maternal age 31.09 (5.38) 30.54 (5.68) 32.50 (5.98) 33.11 (5.81)
Body mass index 25.61 (5.57) 25.17 (5.77) 26.86 (6.78) 27.24 (7.14)
Nulliparity 8818 (44.60) 47 (32.90) 52 (27.80) 23 (21.70)
Previous preterm delivery 740 (3.74) 13 (9.10) 33 (17.65) 16 (15.09)
Smoking 1918 (9.70) 21 (14.68) 31 (16.58) 17 (16.30)
Ethnicity Caucasian Afro-Caribbean Asian Mixed 17889 (91.27) 308 (1.56) 1136 (5.75) 280 (1.42) 131 (92.26) 3 (2.11) 6 (4.22) 2 (1.41) 162 (87.7) 4 (2.14) 16 (8.56) 3 (1.60) 95 (89.62) 2 (1.89) 7 (6.60) 2 (1.89)
Hypertensive disorders of pregnancy 527 (2.70) 4 (2.80) 22 (11.80) 15 (14.20)
Essential hypertension 574 (2.90) 7 (4.90) 13 (7.00) 10 (9.40)
Diabetes type 1 or type 2 77 (0.40) 1 (0.70) 16 (8.56) 14 (15.10)
Gestational diabetes 1146 (5.80) 13 (9.10) 26 (13.90) 13 (14.10)
Gestational age at corticosteroid exposure (days) - 212.54 (19.53) 256.69 (8.59) 259.50 (3.88)
Corticosteroid-to-birth interval (days) - 59.52 (22.21) 8.38 (11.47) 3.34 (1.75)
Gestational age at delivery (days) 280.36 (8.37) 272.06 (9.76) 265.07 (6.88) 269.84 (3.58)
Birthweight centile 62.30 (27.83) 54.16 (26.54) 52.61 (34.02) 46.93 (36.67)
Birthweight <10th centile 847 (4.28) 9 (6.29) 30 (16.04) 22 (20.75)
Planned caesarean delivery 1865 (9.43) 27 (18.88) 127 (67.91) 106 (100.00)