Abstract
Objective: To investigate whether the Antenatal Late Preterm
Steroids (ALPS) trial, has been translated into clinical practice in
Canada and the United States. Temporal trends in optimal and suboptimal
antenatal corticosteroid (ACS) use among late preterm deliveries were
also assessed.
Design: A retrospective cohort study.
Setting: USA and Canada, 2007 to 2020.
Population: All live births in the US (n= 32,476,039) and Nova
Scotia, Canada (n= 116,575).
Methods and Main outcome measured: Using data from the Natality
database and the Nova Scotia Atlee Perinatal Database, ACS
administration within specific categories of gestational age was
assessed by calculating rates per 100 live births. Temporal trends in
optimal, and suboptimal ACS use were also assessed.
Results: In Nova Scotia, the rate of any ACS administration
increased significantly among women delivering at 35-36 weeks, from
15.2% in 2007-2016 to 19.6% in 2017-2020 (OR 1.36, 95%CI 1.14, 1.62).
In the U.S., among live births at 35-36 weeks’ gestation, any ACS use
increased from 4.1% in 2007–2016 to 18.5% in 2017–2020 (OR 5.33,
95% CI 5.28–5.38). Among infants between 24 and 34 weeks’ gestation in
Nova Scotia, 32% received optimally timed ACS, while 47% received ACS
with suboptimal timing. Of the women who received ACS in 2020, 34% in
Canada and 20% in the United States delivered at ≥37 weeks.
Conclusion: Publication of the ALPS trial resulted in increased
ACS administration at late preterm gestation in Nova Scotia, Canada and
the U.S.. However, a significant fraction of women receiving ACS
prophylaxis delivered at term gestation.
Funding: This study was funded by the Canadian Institutes of
Health Research (grant number PJT-173329). NR is supported by a grant
from the Swedish Research Council for Health, Working Life and Welfare
(grant number 4-2702/2019). KSJ is supported by an Investigator award
from the BC Children’s Hospital Research Institute.
Keyword: antenatal corticosteroid, preterm birth, Antenatal
Late Preterm Steroids