METHODS/DESIGN: This protocol describes our randomised controlled trial that tests whether a breastfeeding meditation audio reduces maternal stress in mothers of late preterm infants in London. Home visits will be conducted at 2-3 and 6-8 weeks post-delivery. Participants will be randomised to a control group or an intervention group, where mothers will be asked to listen to a meditation tape on a daily basis while breastfeeding. The main outcomes of the intervention will be maternal stress markers and infant weight Z-score. Potential mediators will be the secondary outcomes and include breast milk macronutrient and hormone levels (ghrelin, leptin, cortisol, and adiponectin), milk volume assessed by 48-h test-weighing, and maternal engagement with the infant. Infant behaviour, including crying and sleeping, and infant appetite will be evaluated. Data about other mediators such as maternal perception of milk supply and salivary oxytocin will be collected.
DISCUSSION: We hypothesise that the use of the breastfeeding meditation will reduce maternal stress and consequently improve infant growth mediated by changes in milk composition and volume and maternal behaviour. This study will allow us to understand the mother-infant factors that influence breastfeeding in late preterm infants and potentially identify a method that could improve mother, infant, and breastfeeding outcomes.
TRIAL REGISTRATION: ClinicalTrials.gov, NCT03791749. Registered 1 January 2019.
MAIN BODY: We argue that broader consideration of lactation, incorporating evolutionary, comparative and anthropological aspects, could provide new insights into breastfeeding practices and problems, enhance research and ultimately help to develop novel approaches to improve initiation and maintenance. Our current focus on breastfeeding as a strategy to improve health outcomes must engage with the evolution of lactation as a flexible trait under selective pressure to maximise reproductive fitness. Poor understanding of the dynamic nature of breastfeeding may partly explain why some women are unwilling or unable to follow recommendations.
CONCLUSIONS: We identify three key implications for health professionals, researchers and policymakers. Firstly, breastfeeding is an adaptive process during which, as in other mammals, variability allows adaptation to ecological circumstances and reflects mothers' phenotypic variability. Since these factors vary within and between humans, the likelihood that a 'one size fits all' approach will be appropriate for all mother-infant dyads is counterintuitive; flexibility is expected. From an anthropological perspective, lactation is a period of tension between mother and offspring due to genetic 'conflicts of interest'. This may underlie common breastfeeding 'problems' including perceived milk insufficiency and problematic infant crying. Understanding this - and adopting a more flexible, individualised approach - may allow a more creative approach to solving these problems. Incorporating evolutionary concepts may enhance research investigating mother-infant signalling during breastfeeding; where possible, studies should be experimental to allow identification of causal effects and mechanisms. Finally, the importance of learned behaviour, social and cultural aspects of primate (especially human) lactation may partly explain why, in cultures where breastfeeding has lost cultural primacy, promotion starting in pregnancy may be ineffective. In such settings, educating children and young adults may be important to raise awareness and provide learning opportunities that may be essential in our species, as in other primates.