Assisted Vaginal Deliveries in Mothers Admitted as Public or Private Patients in Western Australia

BACKGROUND Mothers delivering as private patients in Australia have a high rate of assisted deliveries, which could lead to adverse infant outcomes in this group of patients. We investigated whether the risk of adverse infant outcomes after assisted deliveries was different for mothers admitted as public or private patients for delivery, when compared with unassisted deliveries. METHODS AND FINDINGS We included 158,241 vaginal, singleton, term birth admissions in our study where the infant was live born and without birth defects. The study population was identified from statutory birth and hospital data collections held by the Western Australian (WA) Department of Health. We estimated odds ratios and confidence intervals using logistic regression models adjusted for a range of maternal demographic, pregnancy and birth characteristics. Interaction was assessed by including interaction terms in the models. Outcomes included low Apgar scores at five minutes (< 7), neonatal resuscitation and special care admission. Mothers delivering as private patients had an increased risk of assisted vaginal delivery compared with public patients (adjusted OR 1.74, 95% CI  =  1.68-1.80). Compared with unassisted vaginal deliveries, assisted deliveries were associated with increased risk of Apgar scores at five minutes below 7 (OR 1.25, 1.08-1.45), neonatal resuscitation (OR  =  1.69, 1.42-2.00) and admission to special care nursery (OR  =  1.64, 1.53-1.76). The increased risk of neonatal resuscitation was higher for mothers admitted as private patients for delivery (OR  =  2.13) than public patients (OR  = 1 .55, p(interaction)  =  0.03). CONCLUSIONS Our results suggested that the high risk of neonatal resuscitation following assisted vaginal deliveries compared to unassisted is higher in private patients than public patients. Whether this phenomenon is due to the twofold higher rate of assisted vaginal deliveries in this group of patients or a higher rate of fetal indications for assisted vaginal delivery remains to be answered.