Subjects may join the study at any point during their pregnancy or soon after delivery. If possible, samples of the mother will be obtained three times prior to delivery in the third trimester: at 30, and 4 or fewer days prior to the mother's due date, as well as on the day of birth prior to delivery. If not possible, samples of mothers and babies can be obtained from birth onwards. Samples will be collected from both mother and baby at day 1, day 2 or 3, weekly through the first month, and monthly through the first year. During monthly sampling, a member of the study team will communicate with mothers regularly to assess for any changes in the infant's diet or health between visits.