What does it mean when fluid leaks from the nipples during late pregnancy?

During the third trimester of pregnancy, it is common for some women to notice a clear or milky fluid leaking from the nipples. This fluid is called colostrum—the earliest form of breast milk—produced by the mammary glands in preparation for lactation after delivery. Its appearance typically begins in the second or third trimester and reflects normal hormonal changes, particularly rising levels of prolactin and oxytocin, which stimulate mammary gland development and secretory activity.

Colostrum is usually thick, yellowish or golden in color, and may appear in small amounts—sometimes only visible when the nipple is gently compressed. It is entirely benign and does not indicate preterm labor, infection, or other pathology. However, if the discharge is bloody, unilateral (occurring on only one side), associated with a breast lump, skin changes (e.g., dimpling, redness, or ulceration), or accompanied by pain or fever, further clinical evaluation is warranted to rule out conditions such as intraductal papilloma, duct ectasia, or, rarely, malignancy.

It’s important to reassure patients that spontaneous nipple discharge during late pregnancy is physiologic and expected. No intervention is needed unless concerning features are present. Wearing nursing pads can help manage leakage and maintain comfort and hygiene. Patients should be encouraged to discuss any new or unusual breast symptoms with their obstetric provider during routine prenatal visits.