Investigating the effect of domperidone on breast milk supply following preterm birth- the SUMMIT study

Mothers of preterm infants often struggle to produce enough breast milk to meet the daily feed requirements of their infants, especially in the longer-term. This randomized multi-centre double-blind parallel controlled trial will resolve the issue of whether a higher dose of domperidone (60 mg/day) leads to greater improvements in maternal breast milk supply compared to a lower dose (30 mg/day), while also evaluating differences in adverse events, impacts on breast milk composition, and identifying predictors of treatment response to domperidone. Eligible women will be randomised to a high dose (60 mg/day) or low dose (30 mg/day) domperidone for 21 days. All women will initially commence on the low dose for 2-days before continuing with their assigned treatment dose for a further 19 days. The primary outcome will be assessed at day 21 following treatment initiation. After this point in time, women will be provided with the option to taper their dose to twice daily for four days and then once daily for three days, before stopping. All participants will undertake regular study assessments including at baseline (study enrolment), day 7, 14, 21 of treatment, one-week following intervention, and at infant discharge to home or term corrected (whichever comes first). Women will undergo a breast assessment by a lactation consultant or nurse/midwife, and complete a breast milk diary throughout the study. Women will regularly undertake questionnaires evaluating demographics and lifestyle, breast health, milk expression, postnatal health, mental health and wellbeing, and infant feeding practices. Women will provide breast milk, blood, urine, stool and buccal cell swab samples.