How Prenatal Stress Hormones Impact Heart Development and Future Cardiovascular Health

Recent research from the University of South Australia highlights the significant effects of elevated cortisol levels—commonly known as stress hormones—on fetal heart development, especially in preterm births. When cortisol, vital for organ maturation late in pregnancy, rises prematurely due to maternal stress or medical interventions, it can disrupt normal molecular processes that guide the developing heart.

The study involved administering cortisol to preterm sheep fetuses over a week to mimic the natural hormonal environment of late pregnancy. The findings revealed substantial changes in the molecular signaling pathways essential for proper heart growth, energy metabolism, and cardiovascular stability. Elevated cortisol levels suppress crucial glucocorticoid receptors and disturb key signaling molecules, potentially rendering the heart more prone to future instability.

This research sheds light on how early-life stress factors may predispose individuals to cardiovascular diseases later in life. It emphasizes the importance of carefully managing cortisol levels during pregnancy, especially when corticosteroids are used to promote lung development in preterm infants. Since sheep hearts closely resemble human heart development, these insights are particularly relevant for clinical practices concerning pregnant women at risk of preterm delivery.

Pregnancy complications such as gestational diabetes, preeclampsia, obesity, and placental problems can lead to a premature increase in cortisol, impacting fetal development during critical periods. The study advocates for refined monitoring of corticosteroid use to mitigate long-term health risks for preterm babies.

Authors from the university and collaborating institutions hope this research will inform better prenatal care strategies, ultimately improving outcomes for both mothers and their children.

Source: https://medicalxpress.com/news/2025-06-stress-hormone-womb-early-heart.html