A prolactin test measures the level of the
hormone prolactin, which is made by the
pituitary gland , in your blood.
Pregnant women have high levels of prolactin, which
helps make breast milk. During pregnancy, prolactin levels increase by 10 to 20
times. After the baby is born, prolactin stays high if you are breast-feeding.
In women who do not breast-feed, prolactin levels return to normal soon after
they give birth. After months of breast-feeding, prolactin levels may also
return to normal levels even if you still breast-feed.
pituitary glands of men and nonpregnant women also make prolactin but it is not
clear what it does in the body for these people.
are different throughout the day. The highest levels occur during sleep and
shortly after you wake up. Prolactin levels also get higher during times of
physical or emotional stress.
Many medicines can cause prolactin
levels to go up. Tumors of the pituitary gland can sometimes cause prolactin to
be made. A damaged pituitary gland may not be able to make normal amounts of
prolactin so levels will be lower.
Sarah Marshall, MD - Family Medicine
Deborah A. Penava, BA, MD, FRCSC, MPH - Obstetrics and Gynecology
August 1, 2012