New research shows antenatal steroids delivered by a skin patch could improve preterm birth treatment

A new study led by the Women and Infants Research Foundation (WIRF) has demonstrated for the first time that a transdermal (skin) patch can safely and effectively deliver antenatal steroids to promote preterm fetal lung maturation.

Preterm birth is the leading cause of death and disability among children under five years of age in developed countries. Globally, around 13.4 million babies are born too early each year, with many facing serious complications such as cerebral palsy, chronic lung disease, blindness, and developmental delays.

For decades, antenatal steroids (ANS) have been a cornerstone of obstetric care, given to mothers before premature delivery to accelerate fetal lung maturation and reduce the risk of respiratory complications.

Yet, the treatment has remained largely unchanged since its introduction in the 1970s, relying on painful intramuscular injections that deliver high doses of steroids to both mother and baby and carry potential long-term risks.

Now, research led by Dr Sean Carter from WIRF, in collaboration with the National University of Singapore has demonstrated for the first time that a transdermal patch can safely and effectively deliver antenatal steroids to promote fetal lung maturation. The results were recently published in BMC Medicine.

The study demonstrated that the patch delivers a controlled, low-dose release of the steroid betamethasone – a method shown to accelerate lung maturation as effectively as the standard intra-muscular treatment whilst potentially reducing harm to the developing brain and other organs.

In preterm lamb models, the patch achieved the same improvements in respiratory outcomes as traditional injections, but with up to ten times less drug exposure.

Dr Carter said the findings mark a major advance in maternal-fetal medicine.

“For more than 50 years, antenatal steroids have saved countless lives, but the way these drugs are administered has never been optimised. Our study is the first to show that a patch – which is pain-free, needle-free, and heat-stable – can deliver these drugs effectively and safely,” Dr Carter said.

“Developing a skin patch for antenatal steroid delivery could allow doctors to better control how much drug the mother and fetus receive, how long they are exposed to it, and avoid the ups and downs in dosing that can make treatment less effective.

“Not only is this approach likely to improve outcomes for mothers and babies, but it also has the potential to make treatment more accessible worldwide, including in low-resource and remote settings.”

Unlike injections, the patch can be removed immediately if the risk of preterm birth resolves, providing added safety for mothers and babies.

Its needle-free and heat-stable design also makes it highly suitable for use in regions where cold storage, sterile equipment, or trained clinicians may be unavailable.

Read the full paper Transdermal delivery of antenatal steroids to promote fetal lung maturation: Proof of principle data from sheep and non-human primate models, as published in BMC Medicine on 1 August 2025.