541 - Twenty-year outcomes after repeat doses of antenatal corticosteroids: Follow-up of the ACTORDS randomised controlled trial

Publication Number: 541.6704

Robyn W. May, Liggins Institute, University of Auckland, Auckland, Auckland, New Zealand; Anthony G B. Walters, Liggins Institute, University of Auckland, Auckland, Auckland, New Zealand; Greg Gamble, University of Auckland, Auckland, Auckland, New Zealand; Caroline A. Crowther, University of Auckland, Auckland, Auckland, New Zealand; Stuart Dalziel, University of Auckland, Auckland, Auckland, New Zealand; Carl Eagleton, The Liggin's Institute, Auckland, Auckland, New Zealand; Christopher McKinlay, University of Auckland, Auckland, Auckland, New Zealand; Barry J. Milne, University of Auckland, Auckland, Auckland, New Zealand; Jane E. Harding, Liggins Institute, University of Auckland, Auckland, New Zealand, Auckland, Auckland, New Zealand

Background: Antenatal corticosteroids given to women at risk of preterm birth reduce neonatal morbidity and mortality. For women who remain undelivered and at ongoing risk of preterm birth, weekly repeat dose(s) of corticosteroids up to 32 weeks’ gestation have also been shown to reduce neonatal morbidity and are not associated with any harms in mid-childhood. Nevertheless, concerns remain that this may have been too early to evaluate potential adverse effects on respiratory and other long-term outcomes.

Objective: To assess if exposure to repeat dose(s) of antenatal corticosteroids has beneficial or harmful effects on respiratory and general health in adulthood.

Design/Methods: We assessed the adult offspring of New Zealand participants in the ACTORDS Trial, a multicentre, placebo-controlled trial where women at ongoing risk of preterm birth who had received a single course of corticosteroids were randomised to weekly repeat doses of intramuscular betamethasone or placebo. Follow-up at 20 years included a health questionnaire and consent to access administrative data sources. The primary outcome was any asthma diagnosis. Secondary outcomes included neurodevelopmental, cardiovascular, mental and general health, functional difficulties and social outcomes.

Results: Of 352 infants born to 290 trial participants, we assessed 214 (61%; 96 (45%) female) at mean (standard deviation) age 20.5 (1.5) years. The rate of any asthma diagnosis was similar in both groups (58/107 (54%) repeat bethamethasone versus 50/107 (47%) placebo; risk ratio adjusted for gestational age at trial entry and multiplicity 1.16, 95% confidence interval, 0.89–1.51). Secondary outcomes were similar in both groups.

Conclusion(s): Exposure to repeat dose(s) of antenatal corticosteroids was associated with neither benefit nor harm in early adulthood. Given the established neonatal benefits of repeat antenatal corticosteroids, the widespread uptake of this inexpensive and effective treatment can be further encouraged.