Each year, approximately 15 million babies worldwide are born prematurely, defined as birth before 37 weeks of pregnancy. While advances in neonatal care have improved survival rates for these infants, researchers have long recognized that premature birth carries a heightened risk of chronic kidney disease later in life. However, the precise biological mechanisms underlying this vulnerability have remained unclear—until now.

A recent study led by a team of researchers from Hadassah-University Medical Center in Jerusalem and Monash University in Melbourne has identified the cellular disruption responsible for impaired kidney development in premature infants. Published in the journal iScience, the study reveals that an early transition from the womb to the outside environment induces stress in nephron progenitor cells—precursors to the kidney’s filtration units—disrupting their normal developmental timing and leading to a permanent reduction in nephron number.

Human kidneys rely on roughly one million nephrons, microscopic structures that filter blood and produce urine. These filtration units develop primarily before birth, with nephron formation ceasing around the 35th week of gestation. Because nephrons do not regenerate postnatally, a premature birth interrupts this critical developmental window, resulting in fewer nephrons and decreased kidney reserve throughout life.

Using an advanced mouse model mimicking premature birth, the researchers observed that progenitor cells enter a state of cellular distress within hours after early birth. This stress triggers a molecular response called the unfolded protein response, which prioritizes cell survival over differentiation and nephron formation. Although the cells attempt to compensate by extending nephron-building activity for about 24 hours longer than usual, this delay fails to restore the deficit. When examined at a stage analogous to adulthood, the mice exhibited chronic kidney damage, including enlarged glomeruli, proteinuria, and markers of tubular injury—conditions that parallel kidney dysfunction observed in humans born premature.

The study also noted a gender disparity: male animals showed significant impairments in nephron number and function, while females were comparatively spared. This aligns with previous findings indicating that male fetuses may be more vulnerable to adverse perinatal conditions, potentially informing future risk assessments.

Clinically, these findings have important implications. Epidemiological studies have shown that children and adults born prematurely face increased risks of hypertension, proteinuria, and chronic kidney disease, often becoming apparent only in adolescence or adulthood. The new research suggests that the first days after premature birth represent not only a critical survival period but also a narrow therapeutic window during which interventions could protect or preserve nephron development.

Led by Dr. Morris Nechama and doctoral student Athar Amleh at Hadassah, in collaboration with Dr. Oded Volovelsky and Prof. Alexander Combes from Monash, the team emphasized that while their findings elucidate the mechanism and timing of injury, therapeutic strategies to mitigate progenitor cell stress remain to be developed and tested.

The international collaboration was supported by AUSIMED, an Australian charity promoting medical research ties between Israel and Australia, and persisted despite challenging circumstances, including ongoing regional conflict.

This research marks a significant step toward understanding how premature birth establishes lifelong vulnerability to kidney disease and opens the possibility of future interventions aimed at preserving renal health in this at-risk population.