Pandemic related complications made the study no longer feasible.

An increasing number of children are developing non-communicable diseases that carry immediate and long-term significant societal and economic impacts. Thus, its prevention is imperative with early interventions, such as those that may fall within the first 1000 days, likely to yield better outcomes. The first 1000 days of life represent a period of rapid development sensitive to influences that may be leveraged to promote healthy growth. Breastfeeding is one such modifiable factor. Observational studies have shown that breastfeeding may be associated with reductions in chronic conditions, though its mechanism remains unknown. The complexity of these relationships is furthered by studies showing maternal metabolic status may alter breastmilk composition. Accordingly, this study aims to evaluate the influence of maternal metabolic status on breastmilk composition and assess associations between breastmilk composition and common noncommunicable diseases in childhood.

This project will be completed within TARGet Kids! (The Applied Research Group for Kids), a paediatric primary care research network (NCT01869530). Mother-infant dyads will be recruited and a breastmilk sample obtained at three months of age. Children will then be seen as part of routine care for the next five years to track growth, health and development. This study will provide the opportunity of prospectively following term-born Canadian children to understand the relationship between breastfeeding patterns and child health, its potential underlying mechanisms and how breastmilk composition is modified by maternal metabolic status, which altogether can be used to help set children on optimal developmental trajectories.

STUDY OBJECTIVES:

1. To evaluate the influence of maternal metabolic status, on breastmilk composition (energy, macronutrient and micronutrient content and microbial profile) at three months post-partum.

   • Maternal metabolic status will be characterized by: maternal obesity (measured), diabetes, hypertension and gestational weight gain (self-reported).

2. To assess the associations between breastmilk composition and obesity, asthma and allergy in the children longitudinally to five years of age.

Inclusion Criteria:

• The child is a participant in the TARGet Kids! (The Applied Research Group for Kids) study (NCT01869530)
• The child is between two and four months of age at recruitment.
• The child is healthy.
• Child is fed exclusively mother's milk and has not received any infant formula, cow's milk, juice, tea, or solids in the two weeks prior to recruitment.
• The mother of the child is present at the time of recruitment.

Exclusion Criteria:

• The child was born at <37 weeks gestation.
• The child has been diagnosed with a health condition affecting growth (e.g. failure to thrive, cystic fibrosis).
• The child has been diagnosed with any acute or chronic conditions.
• The family of the child is unable to communicate in English.

Mother-infant dyads will be recruited prospectively within the TARGet Kids! cohort. According to current TARGet Kids! study procedures (NCT01869530), initial contact with families is made by email or letter, from the child's paediatric clinic, two weeks prior to the scheduled visit. Families will also be made aware of the study through posters and informal conversations during early postnatal well-child visits.