Demographics
| Total cohort (5439) | Severe adverse neonatal outcome | OR (95% CI) | P value | ||
| No (n=4800) | Yes (n=639) | ||||
| Age (years) | 31.0 (5.5) | 31.0 (5.5) | 30.3 (5.5) | 0.97 (0.96 to 0.99) | 0.003 |
| BMI (kg/m2) | 25.0 (6.5) | 25.0 (6.5) | 25.1 (6.6) | 1.00 (0.99 to 1.02) | 0.60 |
| Ethnicity | |||||
| Caucasian | 50.7% (2756/5439) | 50.3% (2413/4800) | 53.7% (343/639) | 1 | |
| Indigenous | 3.3% (180/5439) | 3.3% (156/4800) | 3.8% (24/639) | 1.08 (0.66 to 1.77) | 0.76 |
| Asian | 29.6% (1608/5439) | 29.8% (1428/4800) | 28.2% (180/639) | 0.88 (0.71 to 1.08) | 0.22 |
| Other | 16.5% (895/5439) | 16.7% (803/4800) | 14.4% (92/639) | 0.79 (0.60 to 1.04) | 0.09 |
| SEIFA score | 1017 (74) | 1018 (73) | 1011 (76) | 0.999 (0.997 to 0.9999) | 0.04 |
| Diabetes mellitus | 23.9% (1298/5439) | 23.9% (1149/4800) | 23.3% (149/639) | 0.96 (0.77 to 1.20) | 0.73 |
| Hypertension | 8.3% (449/5439) | 8.3% (400/4800) | 7.7% (49/639) | 0.91 (0.65 to 1.28) | 0.58 |
| ART | 4.9% (264/5439) | 4.9% (235/4800) | 4.5% (29/639) | 0.90 (0.58 to 1.41) | 0.66 |
| Smokes | 13.5% (733/5439) | 13.5% (648/4800) | 13.3% (85/639) | 0.98 (0.75 to 1.29) | 0.89 |
| Alcohol | 4.8% (259/5439) | 4.7% (227/4800) | 5.0% (32/639) | 1.07 (0.70 to 1.63) | 0.76 |
| Illicit drug use | 10.6% (578/5439) | 10.4% (497/4800) | 12.7% (81/639) | 1.30 (0.97 to 1.74) | 0.08 |
| Nulliparous | 45.8% (2489/5439) | 43.4% (2081/4800) | 63.9% (408/639) | 2.50 (1.89 to 3.13) | <0.001 |
| IOL | 44.4% (2415/5439) | 43.1% (2067/4800) | 54.5% (348/639) | 1.67 (1.33 to 2.11) | <0.001 |
| Gestation | 38.7 (1.1) | 38.7 (1.1) | 38.7 (1.3) | 0.97 (0.89 to 1.05) | 0.41 |
| Gender (female) | 50.4% (2740/5439) | 50.9% (2443/4800) | 46.5% (297/639) | 0.83 (0.69 to 0.99) | 0.04 |
| Method of birth | |||||
| SVD | 53.2% (2895/5439) | 56.0% (2687/4800) | 32.6% (208/639) | 1 | |
| Instrumental | 13.2% (716/5439) | 10.8% (520/4800) | 30.7% (196/639) | 5.97 (3.52 to 10.13) | <0.001 |
| Emergency CS | 16.4% (890/5439) | 15.1% (726/4800) | 25.7% (164/639) | 3.28 (2.26 to 4.76) | <0.001 |
| Elective CS | 17.3% (938/5439) | 18.1% (867/4800) | 11.1% (71/639) | 1.07 (0.79 to 1.45) | 0.68 |
| US gestation | 36.6 (0.72) | 36.6 (0.7) | 36.5 (0.7) | 0.85 (0.74 to 0.97) | 0.02 |
| Time from ultrasound to birth (days) | 15.3 (8.6) | 15.3 (8.4) | 15.4 (9.5) | 1.00 (0.99 to 1.01) | 0.69 |
| EFW | 2969 (458) | 2976 (452) | 2911 (503) | 0.9997 (0.999 to 0.9999) | 0.002 |
| CPR | 1.99 (0.51) | 2.00 (0.50) | 1.93 (0.55) | 0.73 (0.61 to 0.89) | 0.001 |
| UA PI | 0.83 (0.15) | 0.83 (0.15) | 0.86 (0.16) | 3.89 (1.98 to 7.65) | <0.001 |
| MCA | 1.61 (0.33) | 1.61 (0.32) | 1.59 (0.34) | 0.83 (0.63 to 1.10) | 0.20 |
| EFW z-score | 0.43 (1.10) | 0.45 (1.08) | 0.32 (1.24) | 0.89 (0.82 to 0.97) | 0.01 |
| CPR z-score | −0.15 (1.02) | −0.13 (1.0) | −0.31 (1.12) | 0.83 (0.75 to 0.91) | <0.001 |
| UA PI z-score | 0.09 (1.03) | 0.07 (1.02) | 0.25 (1.13) | 1.20 (1.09 to 1.32) | <0.001 |
| MCA PI z-score | −0.15 (0.98) | −0.14 (0.97) | −0.23 (1.03) | 0.90 (0.82 to 0.99) | 0.04 |
Data are reported as % (n) for categorical data and mean (SD) for continuous data.
ART, artificial reproductive technologies; BMI, body mass index; CPR, cerebroplacental ratio; CS, caesarean section; EFW, estimated fetal weight; IOL, induction of labour; MCA PI, middle cerebral artery pulsatility index; SEIFA, socioeconomic indexes for areas; SVD, spontaneous vaginal delivery; UA PI, umbilical artery pulsatility index; US, ultrasound.