Neonatal galactorrhea occurs in up to 6% of term newborns and is usually secondary to transplacental transfer of maternal estrogen. These hormonal effects (maternal estrogens and endogenous prolactin) lead to palpable breast buds in approximately one-third of all term newborns. Males and females are equally affected. In most cases, the breast enlargement and galactorrhea begin to subside after the 2nd week of life in males and 2 to 6 months in females. Infants with neonatal breast hypertrophy may be predisposed to infections (mastitis or abscess) possibly incited by repetitive manipulation of the enlarged breast bud by a caregiver. The differential diagnosis includes early mastitis with purulent nipple discharge.
Management and Disposition
Treatment is not necessary unless infection is suspected. Parents can be reassured that this is a normal finding, and follow-up to resolution should occur at routine well-child care visits.
Classical presentation includes the presence of clear colostrum-like secretions in newborns with hypertrophied mammary tissue without erythema or tenderness. Persistence of enlarged breast buds beyond 6 months of age should prompt follow-up with a pediatric endocrinologist.
In an older child, galactorrhea may be the presenting sign of hypothyroidism or pathologically elevated prolactin levels.
Female infants may also experience vaginal bleeding in the 1st weeks of life due to withdrawal from maternal hormones.
Witch’s Milk. Milky fluid draining from the nipple in a newborn. (Photo contributor: Michael J. Nowicki, MD.)