Antenatal corticosteroids may reduce the need for respiratory support in late preterm newborns but at the cost of neonatal hypoglycaemia
The administration of antenatal corticosteroids (ANC) is standard practice for threatened preterm deliveries between 24–34 weeks. However, beyond this point, the use of ANC remains controversial.
Now, a new systematic review, led by WA medical researchers found significant evidence supporting the use of ANC in late preterm pregnancies. The study is led by Prof Sanjay Patole, from King Edward Memorial Hospital and Associated Prof Mangesh Deshmukh, from Fiona Stanley Hospital.
Why use ANC?
In Australia and globally, official guidelines recommend the use of ANC in high-risk pre-term deliveries between 24-33+6 weeks of gestation. Based on evidence from randomised controlled trials (RCTs), the use of ANC in this population significantly reduces neonatal mortality and morbidities including respiratory distress syndrome, and intraventricular haemorrhage, acording to a recent report.
However, the benefits of ANC administration for late pre-term pregnancies (34 to 36+6 weeks) are not clear. Some studies suggest benefits, but others show increased risk of adverse effects such as neonatal hypoglycaemia.
“Considering the difficulties in balancing short-term gains vs. potentially serious long-term adverse effects, there is lack of international consensus on use of ANC in late preterm gestation,” Associate Prof Mangesh Deshmukh told Medical Forum.
“Late preterm neonates represent ~70% of total preterm births, which account for ~10% of total births. Given the clinical significance of the issue, and publication of new RCTs in this field, we conducted this systematic review to guide research and clinical practice,” he added.
What the study found
The results of this new systematic review (7 RCTs with 4144 neonates) show significant evidence for benefits of ANC for late preterm neonates, but not without a risk.
“Our systematic review showed that exposure to ANC in late preterm gestation reduced the need for neonatal respiratory support and resuscitation in the delivery room. However, the increased risk of neonatal hypoglycaemia is a significant concern considering it has been reported as an independent predictor of poor neurodevelopmental outcomes in neonates,” Associate Prof Deshmukh said.
The authors note that none of the RCT included in their study reported long-term neurodevelopmental outcomes, in relation to ANC use. “Large definitive trials with adequate follow up for neurodevelopmental outcomes are hence required to assess neonatal benefits and risks after exposure to ANC at late preterm gestation,” he added.
In WA, there is no data available about the use of ANC, the authors explained. “…the decisions regarding use of ANC at late preterm gestation are mostly driven by individual obstetrician’s preference,” Associate Prof Deshmukh said.
Prof Patole and Associate Prof Deshmukh are now planning to conduct a definitive multicentre RCT addressing the benefits and risks of using ANC in late preterm gestation.