An apparatus measures the quantity of milk consumed by an infant during a breast-feeding session. The apparatus includes a brassiere-like garment (30) with openings allowing the breasts to be exposed for nursing an infant. Lining (32) is attached to the inside of the brassiere. Ultra-sonic Doppler-Effect transmitter probes (44) and receiver probes (46) are annexed to the brassiere lining pointing at the direction of the respective nipple of the nursing person. A processor is provided for translating flow measurements by the probes (44, 46) into volume units.