Breastfeeding Longitudinal Observational Study of Mothers and Kids—BLOSOM Cohort ^†

The Breastfeeding Longitudinal Observational Study of Mothers and kids (BLOSOM) is a single-centre prospective cohort study conducted in Perth (Western Australia) that collected data from 2018 to 2020 and aimed to investigate the mechanisms by which human milk affects infant growth, health, and body composition. Pregnant women (n = 119) were recruited from the community and online networks during the third trimester of pregnancy (>30 weeks gestation). Inclusion criteria were women self-reported as healthy with no major pregnancy complications, intention to exclusively breastfeed up to at least 5 months postpartum, and intention to breastfeed until 12 months postpartum. Exclusion criteria included maternal smoking and pregnancy complications, such as preterm labour, preeclampsia, and gestational diabetes mellitus. All participants provided informed written consent to participate in the study, which was approved by the Human Research Ethics Committee at The University of Western Australia (RA/4/20/4023). Twenty-two participants withdrew from the study for various reasons, with n = 97 dyads remaining in the study (97 mothers and 99 infants). Mothers provided a milk sample and answered a demographic background questionnaire at the time of recruitment and an infant and maternal questionnaire during the sample collection day at the follow-up visits (days 2–5, and then months 1, 2, 3, 4, 5, 6, 9, 12, and 24). The samples collected were maternal and infant faeces, human milk, and infant oral swabs. The 24 h milk profile including maternal 24 h milk production and 24 h infant intake of human milk was measured at 3, 9, and 12 months postpartum. Maternal and infant anthropometrics as well as body composition using a bioelectrical impedance analyser ImpediMed SFB7 (ImpediMed, Brisbane, Queensland, Australia) were measured at 3, 6, 9, 12, and 24 months postpartum. Infant and maternal questionnaires collected information on maternal diet and maternal and infant health, including previous medical or surgical history and allergies, current medication including antibiotics, current smoking, the use of commercial milk formula and solid foods, dummy use, the use of a breast pump and nipple shield, nipple pain and trauma, childcare attendance, and pets in home. The cohort description was previously briefly included in several papers that reported major findings in this population [1,2,3,4,5,6].