Breastmilk use in preterm infants <29 weeks' gestational age in Australia, New Zealand and Singapore.

Aims: To describe the prevalence of use of breastmilk and explore demographic characteristics and clinical outcomes associated with breastmilk provision in infants born <29 weeks' gestational age in Australia, New Zealand and Singapore.

Methods: This is a secondary analysis of data from a randomised controlled trial, which enrolled 1273 infants in 13 neonatal units across Australia, New Zealand and Singapore from 2012 to 2015. Infants were classified as formula-fed, donor milk-fed or mother's milk-fed at their first enteral feed and separately, at hospital discharge.

Results: The percentage of infants receiving mother's own milk differed between centres both at first feed (79% to 100%), and at hospital discharge (47.1% to 71.6%). Aboriginal, Torres Strait Islander and Southeast Asian heritage, drug use and smoking were associated with lower rates of fully breastmilk feeding at hospital discharge. There was no significant difference in growth outcomes, length of stay and feeding tolerance between feeding groups.

Conclusions: Achieving high breastmilk feeding rates at hospital discharge for all preterm infants born <29 weeks' gestational age at hospital discharge is possible; however, targeted support for mothers who are Indigenous, Southeast Asian and/or using recreational drugs and/or smoking and/or experiencing social disadvantage may be needed. A better understanding and shared knowledge of practice variations within neonatal units with high breastfeeding rates could improve breastmilk access and equity for preterm infants.

Australian new zealand clinical trials registry: ACTRN12612000503820.