Inclusion Criteria:  Pregnant people, aged 18 to 55 years old, at risk of preterm birth with a singleton or twins between 22 weeks and 0 days and <34 weeks and 6 days gestation who have received only a single dose of Celestone within 24 hours All fetuses must be without compromise as per ultrasound or fetal heart rate monitor (so that waiting 24 hours for the study medication is acceptable). Capable of giving informed, written consent.  Exclusion Criteria:  Contraindication to corticosteroids Systemic corticosteroids for medical conditions during the pregnancy (e.g. lupus, severe asthma, Covid, etc). Previous participation in this trial (in a previous pregnancy) Known severe/life-threatening fetal or pregnant patient condition (e.g. fetal congenital/chromosomal abnormality) Demise of one or more fetuses after 14 weeks and 0 days