It is common practice to repeat antenatal steroid administration after 7 to 10 days in women who continue to be at risk for preterm delivery. However, safety and efficacy of repeated courses have not been established. Mothers of singleton infants who had more than five courses of betamethasone (80-120 mg cumulative dose) were eligible for this cohort study. Index patients (IP) were compared to concurrent controls who had < or = 1 course but were matched for sex and gestational age. Of 35 IP born between 1986 and 1995 in a single perinatal centre, 28 were available for follow-up and could be matched. There was no difference between groups with respect to maternal age and gestational age at delivery. Median gestational age at initial treatment was 26.3 weeks (25th percentile 25.1 weeks, 75th percentile 27.2 weeks) in IP. There was no significant difference between groups in head circumference, length and body weight at birth and at age 4 years. The ability to sit and to walk without assistance and to use two-word phrases was attained at similar ages. The use of glasses or hearing aids, allergies, asthma or recurrent upper respiratory infections were not reported more frequently in IP.
Conclusion: This study failed to ascertain adverse long-term effects of repeated antenatal steroid administration in infants and children to the age of 4 years. In contrast to a similar Australian study, we were unable to demonstrate a lower birth size in exposed infants even though our sample size for women with more than five courses and their cumulative doses were larger.