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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Article info
Publication history
Published online: July 05, 2019
Footnotes
Competing interests: See Acknowledgements.
Each author has indicated that they meet the journal's requirements for authorship.
Identification
Copyright
© 2019 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.
