Fetal growth restriction research gets to the heart of the problem

The problems caused by fetal growth restriction (FGR) can persist well beyond birth, and a new study could explain why these babies face higher cardiac risks later in life – revealing how FGR rewires the heart’s metabolism.

FGR is a condition where a baby does not grow properly in the womb because the placenta cannot supply enough oxygen and nutrients; this latest research published in the American Journal of Physiology: Heart and Circulatory Physiology, shows for the first time that it also alters the chemical machinery of the newborn heart.

Dr Beth Allison’s research specialises in FGR and here, working with Professor Graeme Polglase, her team studied hearts exposed to growth restriction, identifying a markedly different metabolic profile in the first day of life, especially in the pathways the heart relies on to generate energy.

“These early disturbances suggest the heart may struggle to make the normal shift to fatty-acid-based metabolism after birth, helping explain why babies born growth-restricted face higher cardiovascular risks later in life.”

FGR’s effects on the heart

Dr Allison said the heart of a growth-restricted newborn is running on a different biochemical script.

“Zahrah found clear shifts in the metabolites and genes that control how the heart produces energy, with the biggest disruptions in fatty-acid and carnitine pathways, the very systems the heart must switch to immediately after birth.”

“That means the growth-restricted heart may enter postnatal life already at a metabolic disadvantage,” she said.

Prof Polglase said these findings offer a mechanistic explanation for something clinicians have observed for decades.

Problem preset before birth

“Our work shows that the problem doesn’t start in childhood or adulthood – it is preset before birth and the changes mean the heart’s energy machinery fails to mature normally after birth.”

“This gives researchers and clinicians a concrete biological target for future prevention and treatment.” he said.

PhD student Zahrah Azman, the first author on this paper, believes that understanding how FGR changes heart metabolism helps identify early vulnerabilities and potential targets for intervention.

“By uncovering these metabolic shifts, we can guide future strategies to support heart health in growth-restricted infants, potentially improving outcomes from birth and reducing long-term heart disease risk,” she said.