Table 3.
OR for maternal and neonatal pregnancy outcomes during the first year of COVID-19 compared with the previous 2 years in an Australian metropolitan health district
| Outcome | Sample size | Unadj. OR | P value | Model 1 OR | P value | Model 2 OR | P value | Model 3 OR | P value |
| Induction of labour | 34 082 | 0.90 (0.86,0.94) | <0.001 | 0.97 (0.92,1.02) | 0.30 | 0.97 (0.92,1.02) | 0.26 | – | – |
| Caesarean birth | 34 063 | 1.14 (1.09,1.20) | <0.001 | 1.24 (1.17,1.30) | <0.001 | 1.23 (1.17,1.30) | <0.001 | 1.25 (1.19,1.32) | <0.001 |
| Preterm birth | 34 080 | 0.86 (0.79,0.94) | 0.00 | 0.91 (0.83,0.99) | 0.05 | 0.91 (0.83,0.99) | 0.03 | 0.88 (0.80,0.97) | 0.01 |
| Spontaneous preterm birth | 34 080 | 0.76 (0.67,0.85) | <0.001 | 0.88 (0.77,0.99) | 0.04 | 0.88 (0.77,0.99) | 0.04 | 0.85 (0.75,0.97) | 0.02 |
| Small for gestational age at birth | 33 880 | 0.88 (0.81,0.96) | 0.01 | 0.90 (0.82,0.99) | 0.03 | 0.90 (0.82,0.99) | 0.02 | – | – |
| Composite adverse neonatal outcome | 33 632 | 1.03 (0.97,1.09) | 0.38 | 1.08 (1.00,1.15) | 0.03 | 1.08 (1.00,1.15) | 0.04 | – | – |
| Full breastfeeding at hospital discharge | 31 113 | 0.86 (0.81,0.90) | <0.001 | 0.85 (0.80,0.90) | <0.001 | 0.85 (0.81,0.90) | <0.001 | 0.85 (0.80,0.90) | <0.001 |
COVID=1 February 2020–31 January 2021 (n=10 381), pre-COVID=1 January 2018–31 January 2020 (n=23 722).
Composite adverse neonatal includes any: stillbirth, admission to NICU, Apgar score under 7 at 5 min or newborn resuscitation with intubation.
Variables adjusted for in each model:
Model 1: Maternal characteristics: Includes maternal age, area-level socioeconomic status (Index of Relative Socio-economic Disadvantage) quintile, gestational age, parity, ethnicity, BMI (numeric), smoking status and mental health status.
Model 2: Model of care: Model 1 variables and model of pregnancy care variable.
For preterm birth outcome the models are not adjusted for gestational age.
Model 3 outcome of interest: Includes models 1 and 2 covariates and additional covariates as listed below.
Caesarean section birth: birth weight and induction of labour.
Preterm birth: composite maternal complications variable (gestational diabetes or hypertensive disorders of pregnancy).
Breastfeeding: birthweight, mode of delivery, length of stay <24 hours and gestational age/preterm.
BMI, body mass index; NICU, neonatal intensive care unit.