Prolactin

Prolactin (PRL, PRH), also known as luteotropic hormone (LTH), is secreted by the mammotropic cells of the adenohypophysis (anterior pituitary gland). It is responsible for breast growth and lactation during pregnancy and after childbirth. During breastfeeding, the baby’s contact with the nipple triggers the secretion of a hormone called oxytocin in the mother’s body, produced by the mother’s neurohypophysis (posterior pituitary gland), stimulating lactogenesis and milk production for the next feeding. Therefore, elevated prolactin levels are expected in new mothers and pregnant women. Lactation is the process of milk production, and prolactin plays a crucial role. Low prolactin levels prevent lactation, whereas high levels may lead to galactorrhea (milk production outside the lactation period, which can occur in both women and men). Elevated prolactin levels in the blood are referred to as hyperprolactinemia. One possible cause of elevated prolactin is prolactinoma, a benign pituitary tumor.

Symptoms of Prolactinoma

• Production of breast milk when not pregnant or breastfeeding (galactorrhea)
• Nipple discharge
• Headaches
• Vision changes
• Amenorrhea
• Pain or discomfort during intimate relations
• Increased body and facial hair and acne

Hyperprolactinemia can also disrupt the menstrual cycle and cause infertility in women. In men, hyperprolactinemia can reduce sexual drive and cause erectile dysfunction (ED).

Reasons for Prolactin Testing in Blood:

• Determining causes of infertility and menstrual irregularities in women
• Identifying causes of ED, infertility, and azoospermia in men
• Due to hypopituitarism (pituitary-hypothalamus disorders)
• Detecting the presence of prolactinoma
• Investigating galactorrhea (lactation not related to breastfeeding)
• Monitoring prolactinoma therapy effectiveness
• Examining gynecomastia

Symptoms of Hyperprolactinemia in Women
Symptoms differ based on whether the woman is premenopausal. In premenopausal women, excess prolactin may cause:

• Irregular menstrual cycles
• Premature menstrual cessation
• Infertility
• Breast tenderness

Symptoms of Hyperprolactinemia in Men:

• Breast enlargement (gynecomastia)
• Nipple discharge
• Loss of sexual drive
• Erectile dysfunction
• Reduced body hair

Testing Recommendations:

No special preparation is needed for this test. It is recommended to measure prolactin levels during the follicular phase of the menstrual cycle (days 2-4 of the cycle), preferably in the morning. A 20-minute rest before blood collection is advised to ensure the sample is taken in a relaxed state.