A prospective follow-up of the ALPS randomized trial found that children aged 6 years or older exposed to antenatal betamethasone during the late preterm period had similar rates of childhood respiratory impairment compared with those exposed to placebo. The primary composite outcome occurred in 35.3% of the betamethasone group and 35.8% of the placebo group, with no significant differences in abnormal spirometry, asthma diagnosis, or asthma medication use. An exploratory secondary analysis found lower rates of ever having wheezing or whistling in the chest among children exposed to betamethasone. Compared with a term-born reference cohort, children born after threatened late preterm delivery had higher rates of exercise-related wheezing regardless of steroid exposure.