Reproductive outcomes after antenatal corticosteroids: Secondary analysis of 50-year follow-up of the Auckland steroid randomized trial

Introduction: Antenatal corticosteroids are widely used to prevent morbidity and mortality after preterm birth, but there are ongoing concerns about the possible risk of long-term adverse effects, including perturbation of endocrine systems, with potential implications for reproduction. A small number of animal studies have suggested possible adverse effects on reproduction after antenatal exposure to corticosteroids, but there is a paucity of human data.

Material and methods: This is a secondary cohort analysis of the 50-year follow-up of the Auckland Steroid Trial (1969-1974) comparing antenatal exposure to corticosteroids or placebo. Participants whose mothers took part in the placebo-controlled randomized trial of antenatal corticosteroids completed a questionnaire reporting reproductive outcomes at 50 years of age. The main outcome was at least one pregnancy ≥20 weeks or fathered at least one pregnancy ≥20 weeks. Additional outcomes included a number of pregnancies or fathered pregnancies ≥20 weeks, outcomes relating to female reproductive lifespan (including age at menarche and menopause), and outcomes relating to their offspring (including birthweight and gestation).

Results: Of 917 eligible participants, 415 (45% of eligible) completed the questionnaire at a mean (SD) age of 49.3 (1.0) years. The proportion of participants who had experienced at least one pregnancy ≥20 weeks or fathered at least one pregnancy ≥20 weeks was similar in betamethasone and placebo-exposed groups (163/217 [75%] vs. 136/190 [72%]; RR 1.08, (95% CI 0.95 to 1.22); p = 0.23). Participants exposed to betamethasone had a slightly higher number of pregnancies or fathered pregnancies ≥20 weeks compared to those exposed to placebo (mean 1.89 vs. 1.60; marginal mean difference 0.20, (95% CI 0.03-0.37); p = 0.03). Other outcomes, including female reproductive lifespan and offspring-related outcomes, were similar in both randomized groups. There were also no differences in any outcomes between those born preterm and those born at term.

Conclusions: Antenatal exposure to corticosteroids appears to have no clinically important effect on reproductive outcomes to 50 years.