Consortium for the Study of Pregnancy Treatments (Co-OPT): An international birth cohort to study the effects of antenatal corticosteroids

Emily M. Frier, Chun Lin, Rebecca M. Reynolds, Karel Allegaert, Jasper V. Been, Abigail Fraser, Mika Gissler, Kristjana Einarsdóttir, Lani Florian, Bo Jacobsson, Joshua P. Vogel, Helga Zoega, Sohinee Bhattacharya, Eyal Krispin, Lars Henning pedersen, Devender Roberts, Stefan Kuhle, John Fahey, Ben W. Mol, David BurgnerEwoud Schuit, Aziz Sheikh, Rachael Wood, Cynthia Gyamfi-Bannerman, Jessica E. Miller, Kate Duhig, Marius Lahti-Pulkkinen, Eran Hadar, John Wright, Sarah R. Murray, Sarah J. Stock, Quetzal A. Class (Editor)

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Antenatal corticosteroids (ACS) are widely prescribed to improve outcomes following preterm birth. Significant knowledge gaps surround their safety, long-term effects, optimal timing and dosage. Almost half of women given ACS give birth outside the “therapeutic window” and have not delivered over 7 days later. Overtreatment with ACS is a concern, as evidence accumulates of risks of unnecessary ACS exposure.

The Consortium for the Study of Pregnancy Treatments (Co-OPT) was established to address research questions surrounding safety of medications in pregnancy. We created an international birth cohort containing information on ACS exposure and pregnancy and neonatal outcomes by combining data from four national/provincial birth registers and one hospital database, and follow-up through linked population-level data from death registers and electronic health records.

Results and discussion
The Co-OPT ACS cohort contains 2.28 million pregnancies and babies, born in Finland, Iceland, Israel, Canada and Scotland, between 1990 and 2019. Births from 22 to 45 weeks’ gestation were included; 92.9% were at term (≥ 37 completed weeks). 3.6% of babies were exposed to ACS (67.0% and 77.9% of singleton and multiple births before 34 weeks, respectively). Rates of ACS exposure increased across the study period. Of all ACS-exposed babies, 26.8% were born at term. Longitudinal childhood data were available for 1.64 million live births. Follow-up includes diagnoses of a range of physical and mental disorders from the Finnish Hospital Register, diagnoses of mental, behavioural, and neurodevelopmental disorders from the Icelandic Patient Registers, and preschool reviews from the Scottish Child Health Surveillance Programme. The Co-OPT ACS cohort is the largest international birth cohort to date with data on ACS exposure and maternal, perinatal and childhood outcomes. Its large scale will enable assessment of important rare outcomes such as perinatal mortality, and comprehensive evaluation of the short- and long-term safety and efficacy of ACS.
Original languageEnglish
Article numbere0282477
Number of pages27
JournalPLoS ONE
Issue number3
Early online date2 Mar 2023
Publication statusE-pub ahead of print - 2 Mar 2023


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