Prolactin is a hormone produced by the anterior pituitary gland, a tiny peanut-sized gland in the lower part of your brain, just behind the eyes and above the nose. The main function of prolactin is to initiate and control the production of breast milk after delivery. Pregnant and postpartum women normally have high prolactin levels -- the main reason so few women ovulate while breastfeeding.
A prolactin value above 20 ng/mL (nanograms per milliliter) is generally considered above normal. An elevated prolactin level could cause your breasts to produce milk and keep you from ovulating or having menstrual periods, which would certainly make getting pregnant much less likely.
Checking prolactin levels is one of the first tests in an infertility evaluation, especially if a woman has breast-milk leakage, a condition called galactorrhea. Also, prolactin levels can go up if a woman is taking certain tricyclic antidepressants or the high blood pressure medications called calcium channel blockers. Tell your doctor if you're on either type of drug.
If there's no clear-cut cause for the high prolactin level, the next step would be to do a CAT scan or MRI to see if your pituitary gland is enlarged. An enlarged gland that secretes too much prolactin is called a pituitary adenoma or prolactinoma. These enlargements are usually benign and noncancerous.
In addition to false signs of pregnancy like breast-milk discharge, absence of ovulation, and loss of menstrual periods, a person with a prolactinoma may also have these symptoms:
- Mood changes
- Unexplained weight gain
- Reduced libido or sex drive
- Pain during intercourse and/or vaginal dryness
- Eye disturbances
- Fractures from osteoporosis
In the past, prolactinomas were routinely removed by neurosurgeons. Today, this surgery has been abandoned except in cases where the gland has grown significantly in size and is creating pressure in the brain.
High prolactin levels can be treated with a medication called bromocriptine. Within six weeks after a woman starts treatment, ovulation and regular periods will usually commence again. Doctors prescribe daily doses of bromocriptine or have women take it only during the first part of the menstrual cycle until ovulation, and then begin again when the next menstrual period starts.
So there's a good chance that medication could significantly improve your chances of ovulating and having a baby.
You may have heard about an herbal medication made from the "chaste berry" that has been used by European women with menstrual problems for more than 2000 years. In Germany, where the chaste berry is known as Mönchspfeffer (monk's pepper), herbal researchers have found that it helps return ovulation and menstrual cycles to normal.
Though you can buy this medication without a prescription, unfortunately there's no significant pharmacological research showing that chaste berry can lower prolactin levels or that it's an effective treatment for PMS or other menstrual problems. There is also no data on the safety of chaste berry during pregnancy.