Table 1 The variety of circumstances under which milk kinship may be created, as reported in the literature¹

Breastmilk is consumed before the child has attained 24 [2, 45] or 30 months [8] of age

The child has any number of breastmilk feeds [45], at least five feeds [8, 45], or at least 15 feeds [2]

The child receives breastmilk over at least 24 h [2]

The child is fed enough breastmilk to reach satiety [2, 46]

The child is fed by breastfeeding directly enabling a bond to be created [2, 45, 47] and not by other means such as bottle, cup or nasogastric tube

The child is fed breastmilk by any means including by direct breastfeeding, bottle, cup or nasogastric tube [45]

The breastmilk reaches the child’s stomach and contributes to their growth [2, 8]

The donor of the breastmilk is known [48]

There is certainty that all of the conditions to create milk kinship have been met including regarding volume of milk, number of milk feeds, and the identify of milk donor [46, 49]