Antenatal Steroid Therapy May Affect Brain Development in Preterm Infants

New research from Nagoya University suggests that antenatal corticosteroids (ACS), widely used to enhance lung development in preterm infants, may also impact brain development, particularly in regions tied to emotional regulation and motor functions. The study, published in the European Journal of Obstetrics & Gynecology and Reproductive Biology, found that preterm infants exposed to ACS had smaller volumes in two critical brain areas: the amygdala, essential for emotion processing, and the caudate nucleus, key to motor control.

Implications of ACS on Brain Structure

ACS is typically administered to expectant mothers at risk of preterm birth to accelerate fetal lung maturation, significantly improving survival rates and respiratory outcomes. However, the research team, led by Dr. Kazuya Fuma, observed that while ACS has substantial respiratory benefits, it may also influence neurological development. In their study of 59 preterm infants at Nagoya University Hospital, they identified smaller volumes in the amygdala and caudate nucleus in infants exposed to ACS compared to those who were not exposed.

Interestingly, these differences in brain volume were only found in infants born at or after 28 weeks gestation, indicating that the gestational age at birth may influence how ACS affects brain development.

Weighing ACS Benefits Against Potential Risks

The study underscores the need to weigh the well-established respiratory benefits of ACS against its potential effects on brain development. Dr. Fuma emphasized that while ACS is essential for preterm infant care, its broader effects require careful consideration. “Rather than framing the discussion as to whether ACS is ‘safe’ or ‘harmful,’ it is more important to consider the balance between risks and benefits,” he explained.

While ACS remains a crucial intervention for preterm infants due to its impact on survival rates, this study suggests that adjusting its administration could help reduce potential risks to brain development. Dr. Fuma noted that “the next challenge is optimization,” hinting at a need for protocols that consider gestational age to improve outcomes.

Urgent Need for Further Research

Despite the life-saving benefits of ACS, this study highlights an urgent need for more research into its long-term neurological impacts. Understanding the specific effects of ACS on infants born at different gestational ages could enable clinicians to fine-tune treatment approaches, optimizing both immediate and lifelong outcomes for preterm infants.