Prenatal rescue dose of betamethasone in the preterm infant with intrauterine growth restriction

Abstract

Antenatal corticosteroids reduce mortality and respiratory distress syndrome (RDS) in preterm newborns. These benefits decrease after a week of administration, recommending a rescue therapy if there is a new threat of premature delivery. Repeated administration of antenatal corticosteroids may have deleterious effects and their benefits are controversial in intrauterine growth restriction (IUGR). 

Objective: to verify the effects in the IUGR population of antenatal betamethasone rescue therapy on neonatal morbidity and mortality, RDS, and neurodevelopment at 2 years. 

Patients and Method: Retrospective study including ≤ 34 weeks and ≤ 1,500g preterm newborns divided according to antenatal betamethasone exposure: Single-cycle (2 doses) vs Rescue therapy (3 doses). Subgroups were created for those ≥ 30 weeks. Both cohorts were followed up to 24 months of corrected age. The Ages & Stages Questionnaires (ASQ)® was administered to assess neurodevelopment. 

Results: 62 preterm infants with a diagnosis of IUGR were included. The rescue therapy group compared with the single-dose group showed no differences in morbidity and mortality and less intubation rate at birth (p = 0.02), with no differences in respiratory support at 7 days of life. Preterm newborns ≥ 30 weeks exposed to rescue therapy showed higher morbidity and mortality (p = 0.03) and bronchopulmonary dysplasia (BPD) (p = 0.02), showing no differences in RDS. The rescue therapy group showed worse mean scores on the ASQ-3 scale, with no significant differences in cerebral palsy or sensory deficits.

Conclusions: Rescue therapy reduces intubation at birth but does not reduce morbidity and mortality. However, at ≥ 30 weeks, this benefit is not observed and the IUGR population exposed to rescue therapy presented more BPD and lower scores on the ASQ-3 scale at 2 years. Future studies should be aimed at the individualization of antenatal corticosteroid therapy.