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Temporal Trends in Preterm Birth, Neonatal Mortality, and Neonatal Morbidity Following Spontaneous and Clinician-Initiated Delivery in Canada, 2009-2016

      Abstract

      Objective

      Clinician-initiated deliveries at 34 to 36 weeks gestation have increased in Canada since 2006, but the impacts of clinician-initiated deliveries on the overall preterm birth (PTB) rate and concomitant changes in neonatal outcomes are unknown. This study examined gestational age–specific trends in spontaneous and clinician-initiated PTB and associated neonatal mortality and morbidity.

      Methods

      This population-based study included 1 880 444 singleton live births in Canada (excluding Québec) in 2009-2016, using hospitalization data from the Canadian Institute for Health Information. The primary outcomes were neonatal mortality and a composite outcome mortality and/or severe neonatal morbidity identified by International Statistical Classification of Diseases and Related Health Problems, 10th revision, Canada codes. Outcomes were stratified by spontaneous and clinician-initiated deliveries and gestational age categories. Logistic regression yielded adjusted odds ratios (aORs) per 1-year change and 95% confidence intervals (CIs) (Canadian Task Force Classification II-2).

      Results

      The PTB rate remained stable (6.2%) and the proportion of clinician-initiated PTBs increased from 31.0% to 37.9% (P < 0.001). Although overall neonatal mortality remained stable (1.1%), mortality declined among infants born spontaneously at 28 to 33 weeks gestation (aOR 0.92; 95% CI 0.87–0.97). The composite mortality and/or severe morbidity declined from 12.7% to 12.2% (aOR 0.98; 95% CI 0.97–0.99). Declines were observed in the rates of sepsis (aOR 0.96; 95% CI 0.95–0.98) and respiratory distress syndrome requiring ventilation (aOR 0.97; 95% CI 0.96–0.98), whereas rates of intraventricular hemorrhage increased (aOR 1.03; 95% CI 1.01–1.05).

      Conclusion

      With the increase in clinician-initiated deliveries, the stable rates of PTB and neonatal mortality and the decline in composite mortality and/or severe morbidity are encouraging findings. This study adds to clinical understanding of carefully timed and medically justified early interventions.

      Résumé

      Objectif

      La proportion d'accouchements déclenchés par un clinicien entre 34 et 36 semaines de grossesses a augmenté au Canada depuis 2006, mais l'incidence de ces accouchements sur le taux global d'accouchement prématuré et les changements concomitants dans les issues néonatales sont inconnus. Cette étude examinait les tendances propres à l'âge gestationnel dans les accouchements prématurés spontanés et déclenchés par un clinicien, ainsi que la mortalité et la morbidité néonatales associées.

      Méthodologie

      Cette étude fondée sur la population portait sur 1 880 444 naissances vivantes d'un seul bébé au Canada (excluant le Québec) de 2009 à 2016, recensées dans les données d'hospitalisation de l'Institut canadien d'information sur la santé. Les issues primaires étaient la mortalité néonatale et une issue composite comprenant la mortalité et la morbidité grave néonatales notées selon les codes canadiens de la Classification internationale des maladies et des problèmes de santé connexes, dixième révision. Les issues ont été stratifiées selon si les accouchements étaient spontanés ou déclenchés par un clinicien, et selon l'âge gestationnel. Un modèle de régression logistique a été utilisé pour calculer les rapports de cotes ajustés (RCA) selon le changement annuel et obtenir des intervalles de confiance (IC) à 95 % (classification II-2 du Groupe d'étude canadien).

      Résultats

      Le taux d'accouchement prématuré est demeuré stable (6,2 %) et la proportion d'accouchements prématurés déclenchés par un clinicien est passée de 31,0 % à 37,9 % (P < 0,001). Bien que la mortalité néonatale globale soit restée stable (1,1 %), la mortalité a diminué chez les bébés nés spontanément entre 28 et 33 semaines de grossesses (RCA : 0,92; IC à 95 %: 0,87–0,97). L'issue composite de mortalité et de morbidité grave a diminué de 12,7 % à 12,2 % (RCA : 0,98; IC à 95 %: 0,97–0,99). Nous avons observé une baisse des taux de sepsie (RCA : 0,96; IC à 95 %: 0,95–0,98) et de syndrome de détresse respiratoire nécessitant une ventilation (RCA : 0,97; IC à 95 % : 0,96–0,98), mais une augmentation du taux d'hémorragie intraventriculaire (RCA : 1,03; IC à 95 %: 1,01–1,05).

      Conclusion

      Vu l'augmentation du nombre d'accouchements déclenchés par un clinicien, la stabilité des taux d'accouchement prématuré et de mortalité néonatale et la diminution de l'issue composite de mortalité et de morbidité grave sont des résultats encourageants. Cette étude améliore la compréhension clinique des interventions précoces médicalement justifiées et pratiquées au moment opportun.

      Key Words

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