In human newborns, sucrose taste arrests crying and increases mouthing and hand-mouth contact, but colostrum and mature foremilk does not. To determine if mature hindmilk taste has similar effects, 20 normal 10 day old infants who were crying spontaneously for ≥ 15 consecutive seconds were randomized to receive 250 ul of their mother's hindmilk X 5 at 30 second intervals by pipette to the midline anterior tongue prior to one feed and water prior to another. Per cent time crying, mouthing, and hand-mouth contact were calculated for baseline (used as a covariate), administration intervals and up to three minutes following administration. Crying reduction was similar for both liquids during administration (67 vs. 63%), remained less in each minute following breast milk (74, 74, 71%), but increased (73, 83, 89%) following water (solution X period interaction: F[6, 114]=2.5;P=.03). Mouthing was elevated during administration (29% for both), but returned to baseline (< 13%) within two minutes (period effect F[5,90]=2.9;P=.02). There was no change in hand-mouth contact.

Conclusion. Relative to water, hindmilk has a quieting effect following intraoral presentation, but does not increase mouthing or hand-mouth contact. Breastmilk taste may have a contributory role in behavioural state regulation after feeding.