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

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.

Antenatal Betamethasone Every 12 Hours in Imminent Preterm Labour

Background: Benefits of antenatal corticosteroids have been established for preterm infants who have received the full course. In imminent preterm labours there is no time to administer the second dose 24 h later. Objective: To determine whether the administration of two doses of betamethasone in a 12 h interval is equivalent to the effects of a full maturation. Methods: We performed a retrospective cohort study including preterm infants ≤34 weeks gestational age at birth and ≤1500 g, admitted to an NICU IIIC level in a tertiary hospital from 2015 to 2020. The population was divided into two cohorts: complete maturation (CM) (two doses of betamethasone 24 h apart), or advanced maturation (AM) (two doses of betamethasone 12 h apart). The primary outcomes were mortality or survival with severe morbidities. The presence of respiratory distress syndrome and other morbidities of prematurity were determined. These variables were analysed in the neonates under 28 weeks gestational age cohort. Neurodevelopment at 2 years was evaluated with the validated Ages and Stages Questionnaires^®, Third Edition (ASQ^®-3). Multiple regression analyses were performed and adjusted for confounding factors. Results: A total of 275 preterm neonates were included. Serious outcomes did not show differences between cohorts, no increased incidence of morbidity was found in AM. A lower percentage of hypotension during the first week (p = 0.04), a tendency towards lower maximum FiO₂ (p = 0.14) and to a shorter mechanical ventilation time (p = 0.14) were observed for the AM cohort. Similar results were found in the subgroup of neonates under 28 weeks gestational age. There were no differences in cerebral palsy or sensory deficits at 24 months of corrected age, although the AM cohort showed a trend towards better scores on the ASQ3 scale. Conclusions: Administration of betamethasone every 12 h showed similar results to the traditional pattern with respect to mortality and severe morbidities. No deleterious neurodevelopmental effects were found at 24 months of corrected age. Earlier administration of betamethasone at 12 h after the first dose would be an alternative in imminent preterm delivery. Further studies are needed to confirm these results.