Statistical analysis
We fitted logistic regression models to estimate the association between exposure to ACS and the following neonatal outcomes: respiratory distress, hypoglycaemia requiring parenteral therapy, admission to high-level nursery, and receipt of intravenous antibiotics for suspected sepsis. We assessed if the association between exposure to ACS and the outcomes were modified by gestational age by fitting separate interaction terms between ACS and gestational age for each outcome and testing the interactions with likelihood ratio tests. Gestational age modified the associations between exposure to ACS and the outcomes (p-values from likelihood ratio tests were <0.001); the associations are presented stratified by gestational age (grouped as 36+0- 36+6; 37+0– 37+6; and 38+0 – 38+6).
Data were analysed using Stata version 16.1 (College Station, Texas). A p-value < 0.05 was used to determine statistical significance.