Colostrum, a sweet and watery pre-milk, is most often seen on pregnant women's shirts. Sometime between the end of the first trimester and the third trimester, breasts begin to produce the thick and yellow liquid, which later becomes pale and almost colorless, and provides newborns protection against disease and bacterial infection during the first few days of life, Bonnie Herbst, R.N., a board-certified lactation consultant at The Ohio State University Medical Center. Rich in protein and antibodies, colostrum has less fat and sugar than mature milk, which comes in a few days after delivery.
Many women experience pregnant squirts in which they leak small amounts of colostrum, but others just find dried colostrum on their nipples, and others notice nothing different. All of these are within the range of normal, Bibeau says. Discharge may occur at any time or when stimulated through massage or sexual arousal. If you're worried about colostrum leakage, you can wear disposable or washable breast pads, Bibeau says. Allow your breasts to air-dry a few times each day and after showering.