Antenatal corticosteroids for impending late preterm (34-36+6 weeks) deliveries—A systematic review and meta-analysis of RCTs

Abstract

Background Administration of antenatal corticosteroids (ANC) for impending preterm delivery beyond 34 weeks of gestation continues to be a controversial issue despite various guidelines for obstetricians and gynaecologists. Objective To compare outcomes following exposure to ANC for infants born between 34–36+6 weeks’ gestation. Methods A systematic review of randomised controlled trials (RCT) reporting neonatal outcomes after ANC exposure between 34–36+6 weeks’ gestation using Cochrane methodology. Databases including PubMed, Embase, Emcare, Cochrane Central library and Google Scholar were searched in May 2020. Primary outcomes: (1) Need for respiratory support (Mechanical ventilation, CPAP, high flow) or oxygen (2) Hypoglycemia. Secondary outcomes included respiratory distress syndrome (RDS), transient tachypnoea of newborn (TTN), need for neonatal resuscitation at birth [only in the delivery room immediately after birth (not in neonatal intensive care unit (NICU)], admission to NICU, mortality and developmental follow up. Level of evidence (LOE) was summarised by GRADE guidelines. Main results Seven RCTs (N = 4144) with low to high risk of bias were included. Only one RCT was from high income countries, Meta-analysis (random-effects model) showed (1) reduced need for respiratory support [5 RCTs (N = 3844); RR = 0.68 (0.47–0.98), p = 0.04; I2 = 55%; LOE: Moderate] and (2) higher risk of neonatal hypoglycaemia [4 RCTs (N = 3604); RR = 1.61(1.38–1.87), p<0.00001; I2 = 0%; LOE: High] after ANC exposure. Neonates exposed to ANC had reduced need for resuscitation at birth. The incidence of RDS, TTN and surfactant therapy did not differ significantly. None of the included studies reported long-term developmental follow up. Conclusions Moderate quality evidence indicates that ANC exposure reduced need for respiratory support, and increased the risk of hypoglycaemia in late preterm neonates. Large definitive trials with adequate follow up for neurodevelopmental outcomes are required to assess benefits and risks of ANC in this population.

Administration of Antenatal Corticosteroids: Current State of Knowledge

“…Because of the administration of betamethasone, the rate of neonatal hypoglycemia in the study group was significantly increased, although this was expected (RR 1.60, 95% CI: 1.37 – 1.87) 43 . This was also confirmed in subsequent meta-analyses (RR 1.61, 95% CI: 1.38 – 1.87) 44 , 45 .…”

Re: The role of antenatal corticosteroids in improving neonatal outcomes

“…A recent meta-analysis by Mangesh et al, which included seven RCTs, showed reduced need for respiratory support in the steroid category (relative risk 0.68), while neonatal hypoglycaemia risk was high. 3 Interestingly, the recent paper by Badreldin et al showed no respiratory benefit of ACS in late preterm deliveries. 4 Another high-risk group is neonates of type 1 and type 2 diabetic pregnant mothers, who have a 48% risk of hypoglycaemia.…”

Choice of Antenatal Steroids for Prevention of Complications of Prematurity: Betamethasone Versus Dexamethasone

“…Different guidelines also differ widely (Table 1). In a recent metanalysis, Deshmukh and Patole 17 have summarized the evidence from 7 RCTs, n = 4,143 in the late preterm population. There was moderate quality of evidence of benefit in reducing the need for respiratory support.…”

“…There was no data on long-term outcomes. 17 Considering the impact of hypoglycemia and no differences in outcomes related to RDS, surfactant, or admission, it is therefore better to restrict use of antenatal corticosteroids to cases where there is documented evidence of fetal lung immaturity by amniotic fluid analysis until further research.…”