(181) Antenatal Corticosteroid Exposure and Risk of Childhood Allergy

Antenatal corticosteroids (ACS) are routinely used to enhance fetal lung maturity in threatened preterm birth. However, their immunomodulatory effects may impact fetal immune development and increase susceptibility to allergic disease. As ACS use expands to borderline indications, understanding long-term safety is critical. This study evaluated whether ACS exposure is associated with increased risk of allergic disease in early childhood and whether this association persists through age 3.

Study Design:

Secondary analysis of a prospectively followed cohort of 2,252 mother–infant dyads delivered between 2015–2022. ACS exposure was defined as intramuscular corticosteroid administration during pregnancy. Maternal and neonatal data were extracted from electronic records. Allergic outcomes—atopic dermatitis, food allergy, and hyperreactive airway disease (HRAD)—were assessed through structured pediatric follow-up at ages 1, 2, and 3. Associations were evaluated using chi-square and multivariable logistic regression adjusting for maternal age, parity, gestational age, birthweight, gender, delivery mode, hypertensive disorders, ethnicity, and residence. Due to attrition, 2,251 infants were followed at year 1, 1,901 at year 2, and 1,726 at year 3.

 

Results:

Among 1,241 ACS-exposed and 1,011 unexposed infants, the exposed group had lower gestational age (37.6 vs. 39.1 weeks), lower birthweight (3091g vs. 3298g), and higher rates of cesarean and preterm birth. At age 1, atopic comorbidity was more prevalent in ACS-exposed infants (5.3% vs. 3.1%, p=0.015), remaining significant after adjustment (aOR 1.89; 95% CI 1.22–2.92; p=0.004). No significant difference was observed at age 2, but by age 3, prevalence was again higher (7.1% vs. 1.4%, p=0.002; aOR 1.55; 95% CI 1.06–2.28). 

Conclusion:

ACS exposure was independently associated with increased risk of allergic disease in early childhood. While ACS remains vital for preterm neonatal outcomes, its long-term immunologic impact warrants further research and careful risk-benefit consideration.