This tool estimates the probability of survival to discharge for babies without major congenital anomalies born alive below 32 weeks’ gestation and admitted to a UK neonatal unit. It is intended primarily for health professionals and researchers and should not replace advice from neonatal healthcare professionals for parents about the prognosis of any individual baby.

Every baby is unique. The tool provides a range which reflects the uncertainty around the estimate because outcomes can vary, even between babies with similar characteristics. The true survival probability is expected to fall within the predicted range about 95% of the time. There is a 5% chance that the true survival probability falls outside this interval.

The tool takes into consideration a baby’s gestational age at birth, their birthweight, sex, whether they were one of a multiple birth, and whether their mother received treatment with steroids before delivery. These are major factors that influence survival, but there are many others that may also affect an individual baby’s outcome.

The tool is based on synthetic data created using information in the National Neonatal Research Database from approximately 22,000 babies born between 1st August 2021 to 31st December 2024. By “synthetic” we mean artificially generated data that replicates the structure and patterns of real data but does not contain any information relating to any individual real patients.

If you are a parent of a preterm baby with questions about your own baby's prognosis, please talk to a member of your baby's neonatal healthcare team. You can also visit the Bliss and British Association of Perinatal Medicine websites for more information about preterm birth, neonatal care, and the support available to you.