Association of timing of initial breastfeeding and neonatal outcome in very preterm infants: a multicentre cohort study in China.

Objective: To evaluate the association between the timing of initial breastfeeding and the risk of necrotising enterocolitis (NEC) and other neonatal outcomes in very preterm infants (VPIs, <32 weeks' gestation).

Design: Multicentre observational cohort study.

Setting: Data were collected from 102 tertiary neonatal intensive care units (NICUs) in China between 2019 and 2023 through the Chinese Neonatal Network.

Patients: A total of 12 679 VPIs admitted to NICUs within 24 hours of birth and initially breastfed within 7 days were included.

Interventions: Infants were categorised into four groups based on initial breastfeeding timing: within 24 hours (n=2242), 24-48 hours (n=3657), 48-72 hours (n=1870) and after 72 hours (n=4910, reference group).

Main outcome measures: The primary outcome was NEC (stage ≥2). Secondary outcomes included mortality, bronchopulmonary dysplasia, severe neurological injury, severe retinopathy of prematurity, late-onset sepsis, NICU length of stay and intravenous nutrition duration.

Results: Early breastfeeding initiation (<24 hours) was associated with a higher incidence of NEC (7.5% vs 4.3%, OR 1.92, 95% CI 1.21 to 3.06). No significant NEC risk increase was observed for feeding initiation after 24 hours. Early breastfeeding was linked to a shorter duration of intravenous nutrition (median 15 days (IQR 10-27) vs 22 days (IQR 14-33), mean difference -3.93 days, 95% CI -6.57 to -1.3). Subgroup analysis revealed increased NEC risk in neonates delivered via caesarean section, those receiving blood transfusions and those born <28 weeks' gestation.

Conclusions: While early breastfeeding initiation (<24 hours) reduces intravenous nutrition duration, it may elevate NEC risk in specific high-risk subgroups. Feeding strategies should be individualised based on gestational age, delivery mode and transfusion status. Further randomised trials are needed to optimise early feeding protocols for VPIs.