Does progesterone prophylaxis to prevent preterm labour improve outcome? (OPPTIMUM)

A daily progesterone pessary could prevent preterm birth and improve long-term health outcomes for babies born early. Preterm delivery is the leading cause of death and disability among UK newborns, yet no drug has been proven to improve outcomes by stopping labour from starting early. Recent evidence suggests progesterone may cut the risk of preterm delivery, but it remains unclear whether this translates into healthier babies and children. This trial tests whether progesterone given to high-risk pregnant women from mid-pregnancy onward reduces preterm birth, improves the baby’s immediate health—including brain damage and lung disease—and boosts cognitive development at age two. The researchers will also calculate whether the treatment saves NHS money overall. If successful, the research could change standard maternity care, giving clinicians a simple, low-cost tool to prevent preterm labour and its devastating consequences. For families, this means fewer babies dying or growing up with disabilities. For the NHS, it could reduce the long-term costs of caring for premature infants. The study directly addresses a critical gap: proving that preventing preterm birth actually improves the child’s life, not just the timing of delivery.