Objective To explore the factors associated with adverse digestive system outcomes in neonates with jaundice.

Methods A retrospective analysis was conducted on clinical data of hospitalized neonates admitted to the Department of Neonatology, the First Hospital of Jilin University, within 7 days after birth from December 2019 to December 2024. Included neonates underwent serum total bilirubin testing, with post-birth serum total bilirubin levels exceeding the high-risk neonatal phototherapy threshold. Propensity score matching and inverse probability weighting were used to group the jaundiced neonates according to the presence or absence of adverse digestive system outcomes. Factors including basic demographic information of the neonates and their mothers, relevant laboratory examinations, and therapeutic interventions were collected. Traditional logistic regression and Cox proportional hazards models were applied to analyze and predict risk factors for adverse digestive system outcomes in jaundiced neonates.

Inclusion Criteria:

1. Neonates admitted to the Department of Neonatology within 7 days after birth.
2. Clinical diagnosis of neonatal jaundice, with a measured serum total bilirubin level exceeding the phototherapy threshold for hyperbilirubinemia.
3. Availability of complete medical records and serum bilirubin test results.
4. Hospitalized at the First Hospital of Jilin University between December 2019 and December 2024.

Exclusion Criteria:

1. Major congenital anomalies (e.g., severe gastrointestinal malformations, complex congenital heart disease).
2. Missing essential data for primary outcome or key exposure variables.
3. Length of hospital stay < 24 hours.

The study population is a retrospective cohort of neonates hospitalized in the Department of Neonatology at the First Hospital of Jilin University between December 2019 and December 2024. All included neonates were admitted within the first 7 days of life and were diagnosed with neonatal hyperbilirubinemia, defined as having a serum total bilirubin level exceeding the phototherapy threshold for their respective postnatal age and gestational age. This cohort will be analyzed to investigate the risk factors associated with the development of adverse digestive system outcomes.

The individual participant data are derived from retrospective medical records. Data sharing is restricted by the hospital's data governance policies and Chinese regulations on personal information protection.