Temporal Trends in Late Preterm and Early Term Birth Rates in 6 High-Income Countries in North America and Europe and Association With Clinician-Initiated Obstetric Interventions
Research output: Contribution to journal › Journal article › Research › peer-review
Jennifer L. Richards, Michael S. Kramer, Paromita Deb-Rinker, Jocelyn Rouleau, Laust Mortensen, Mika Gissler, Nils-Halvdan Morken, Rolv Skjaerven, Sven Cnattingius, Stefan Johansson, Marie Delnord, Siobhan M. Dolan, Naho Morisaki, Suzanne Tough, Jennifer Zeitlin, Michael R. Kramer
Objective: To describe recent trends in late preterm and early term birth rates in 6 high-income countries and assess association with use of clinician-initiated obstetric interventions.
Design: Retrospective analysis of singleton live births from 2006 to the latest available year (ranging from 2010 to 2015) in Canada, Denmark, Finland, Norway, Sweden, and the United States.
Exposures: Use of clinician-initiated obstetric intervention (either labor induction or prelabor cesarean delivery) during delivery.
Main Outcomes and Measures: Annual country-specific late preterm (34-36 weeks) and early term (37-38 weeks) birth rates.
Results: The study population included 2 415 432 Canadian births in 2006-2014 (4.8% late preterm; 25.3% early term); 305 947 Danish births in 2006-2010 (3.6% late preterm; 18.8% early term); 571 937 Finnish births in 2006-2015 (3.3% late preterm; 16.8% early term); 468 954 Norwegian births in 2006-2013 (3.8% late preterm; 17.2% early term); 737 754 Swedish births in 2006-2012 (3.6% late preterm; 18.7% early term); and 25 788 558 US births in 2006-2014 (6.0% late preterm; 26.9% early term). Late preterm birth rates decreased in Norway (3.9% to 3.5%) and the United States (6.8% to 5.7%). Early term birth rates decreased in Norway (17.6% to 16.8%), Sweden (19.4% to 18.5%), and the United States (30.2% to 24.4%). In the United States, early term birth rates decreased from 33.0% in 2006 to 21.1% in 2014 among births with clinician-initiated obstetric intervention, and from 29.7% in 2006 to 27.1% in 2014 among births without clinician-initiated obstetric intervention. Rates of clinician-initiated obstetric intervention increased among late preterm births in Canada (28.0% to 37.9%), Denmark (22.2% to 25.0%), and Finland (25.1% to 38.5%), and among early term births in Denmark (38.4% to 43.8%) and Finland (29.8% to 40.1%).
Conclusions and Relevance: Between 2006 and 2014, late preterm and early term birth rates decreased in the United States, and an association was observed between early term birth rates and decreasing clinician-initiated obstetric interventions. Late preterm births also decreased in Norway, and early term births decreased in Norway and Sweden. Clinician-initiated obstetric interventions increased in some countries but no association was found with rates of late preterm or early term birth.
|Journal||J A M A: The Journal of the American Medical Association|
|Number of pages||10|
|Publication status||Published - 26 Jul 2016|