Neonatal Adverse Outcomes among Hospital Livebirths in Canada: A National Retrospective Study.

Introduction: In Canada, newborn morbidity far surpasses mortality. The neonatal adverse outcome indicator (NAOI) summarizes neonatal morbidity, but Canadian trend data are lacking.

Methods: This Canada-wide retrospective cross-sectional study included hospital livebirths between 24 and 42 weeks' gestation, from 2013 to 2022. Data were obtained from the Canadian Institute of Health Information's Discharge Abstract Database, excluding Quebec. The NAOI included 15 newborn complications (e.g., birth trauma, intraventricular hemorrhage, or respiratory failure) and seven interventions (e.g., resuscitation by intubation and/or chest compressions), adapted from Australia's NAOI. Rates of NAOI were calculated by gestational age. Unadjusted rate ratios (RR) and 95% confidence interval (CI) were calculated for neonatal mortality, neonatal intensive care unit (NICU) admission, and extended hospital stay, each in relation to the number of NAOI components present (0, 1, 2, 3, 4, or ≥5).

Results: Among 2,821,671 newborns, the NAOI rate was 7.6%. NAOI increased from 7.3% in 2013 to 8.0% in 2022 (p < 0.01). NAOI prevalence was highest in the most preterm infants. Compared to no NAOI, RRs (95% CI) for mortality were 8.5 (7.6-9.5) with 1, 118.1 (108.4-128.4) with 3, and 395.3 (367.2-425.0) with ≥5 NAOI components. Respective RRs for NICU admission were 6.7 (6.6-6.7), 11.2 (10.9-11.3), and 11.9 (11.6-12.2), and RR for extended hospital stay were 6.6 (6.4-6.7), 12.2 (11.7-12.7), and 26.4 (25.2-27.5). International comparison suggested that Canada had a higher prevalence of NAOI.

Conclusion: The Canadian NAOI captures neonatal morbidity using hospitalization data and is associated with neonatal mortality, NICU admission, and extended hospital stay. Newborn morbidity may be on the rise in recent years.