Overall, 65-90% of neonates have breast tissue (1)
results from the transfer of maternal and placental oestrogen and progesterone
persists up to several months
Notes:
neonatal breast enlargement is a normal response to falling levels of maternal estrogen at the end of pregnancy
these trigger the release of prolactin from the newborn's pituitary
neonatal breast enlargement is common is independent of the sex of the baby
generally bilateral - although may not be symmetrical; if unilateral then consider breast abscess; also infective mastitis can occur in a neonate and consider this especially if neonate is unwell and breast enlargement has features of infection (e.g. heat, erythema)
usually occurs in the first week of life and generally resolves within a few weeks (2) - but may persist for several months (1)
enlarged breast may discharge liquid; this usually resolves without treatment over a period of a few weeks
squeezing the breast to facilitate the discharge may lead to irritation, further enlargement, the persistence of the hypertrophied tissue, or, in rare cases, infection (mastitis or abscess)
Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page