The most common cause of galactorrhea is overproduction of the hormone prolactin (hyperprolactinemia) due to a tumor in the pituitary gland. Hyperprolactinemia can cause galactorrhea, or unexpected milk production, and infertility in both men and women.

Can a woman with galactorrhea get pregnant?

When this happens, a woman might have trouble getting pregnant or her breasts may start producing milk outside of pregnancy (galactorrhea). Ninety percent of women with galactorrhea also have hyperprolactinemia.

Can a woman with high prolactin get pregnant?

High prolactin levels inhibit secretion of FSH, which is the hormone that triggers ovulation. So, if your prolactin levels are high, your ovulation may be suppressed. This is why women who are breastfeeding (and thus have high levels of prolactin) usually don't become pregnant.