Got Milk? Project
Humans are physiologically adapted for mother-infant close-contact.
In the evolutionary past, similar to non-primates today, human mothers and infants would spend weeks after birth in continued close contact as infant survival depended on proximity to its mother. Partly this is due to the composition of human breast milk which is low in fat, high in sugar, and has a thin watery texture. This means that it is quickly digested by the infant, who therefore needs to suckle frequently.
Mother-infant skin-to-skin contact immediately postpartum is essential for initiating breastfeeding. It is during this time that infants, guided by smell, perform prefeeding and nipple-seeking behaviours. Skin-to-skin contact also: Regulates infant temperature; Synchronises mother-infant heart rate; Soothes and calms infants; Promotes sleep.
Mother-infant close-contact in the early postpartum period is also vital for the development of a mother's milk production
- Prolactin is the hormone that controls milk production.
- Successful milk production is dependent upon frequent nipple stimulation.
- Prolactin levels increase immediately postpartum, and further rise and fall in relation to the frequency, duration, and intensity of nipple stimulation.
- Lactogenesis II (LII, the onset of copious milk production) is dependent upon how much prolactin the mother secretes.
- It has been discovered that the frequency of suckling on the 2nd day postpartum is directly and positively correlated to milk production on the 5th day.
- It is thought that frequent stimulation of prolactin secretion in the early postpartum period before LII, increases subsequent milk production
In 2006, researchers from Durham University's Parent-Infant Sleep Lab demonstrated that infants who were in close-contact with their mothers while in hospital (via bed sharing or the use of a side-car crib: a 3-sided bassinette attached to the mothers bed), had more opportunities to suckle, showed a greater effort to breastfeed, and did so more frequently, than mothers whose infants were physically separated in hospital by stand-alone bassinettes.
The ‘Got Milk?' Project
The purpose of this research was to explore whether mothers whose infants are located in a side-car crib will experience the onset of LII earlier than mothers whose infants are located in stand-alone bassinettes. We believe that this is the result of increased prolactin production by women experiencing more frequent suckling.
The ‘Got Milk?' Project was the sister-study of a randomised trial called the North-East Cot Trial (NECOT Trial), which took place at the RVI in Newcastle. Data for The ‘Got Milk?' Project was collected using a short questionnaire-style home diary. The home diaries ask mothers about their experiences of lactation i.e. how many times they breastfed in a day, the sensations they felt in their breasts prior to LII , and whether they thought their milk had ‘come in' - which indicates the onset of LII. Mothers were asked to fill in the diary once a day until their baby is 5 days old.
Lyn Robinson (now Dr.) was the project coordinator for The ‘Got Milk?' Project for her MSc in Biological Anthropology.