Background
Recently released patient blood management guidelines for maternity patients in Australia highlighted the lack of evidence on functional outcomes post‐transfusion.

Aim
This study aimed to determine the association between red blood cell transfusion and breastmilk feeding at discharge.

Materials and Methods
Population‐based cohort study of all births (n = 522 534) of at least 20 weeks gestation or 400 g birthweight in New South Wales, 2007–2012. Multivariable Poisson regression was used to analyse the association between red cell transfusion post‐delivery and breastfeeding at discharge among women experiencing a postpartum haemorrhage (PPH).

Results
Overall, 461 395 of 522 534 maternities were breastmilk feeding at discharge, a rate of 88% (82% exclusive; 6% partial). Of 35 588 maternities with a PPH that did not receive a transfusion, 31 387 were breastmilk feeding at discharge (88%; 81% exclusive; 7% partial). There were 4561 maternities with a PPH that were transfused and 3737 were breastmilk feeding at discharge (82%; 70% exclusive; 12% partial). After adjusting for differences in clinical and demographic characteristics, women receiving transfusions are 0.91 (99%CI: 0.89–0.93) times as likely to exclusively breastmilk feed at discharge, compared to nontransfused women. The rate of any breastmilk feeding is 0.94 (99% CI: 0.92–0.95) times lower for transfused women, compared to nontransfused women.

Conclusions
Transfused women have reduced breastmilk feeding rates at discharge. Caution is warranted when advising women that transfusion promotes breastmilk feeding. Additional lactation support may be required for transfused women.