590 Obstetrics and Gynecology Board Review •••
Idiopathic hyperprolactinemia
Decreased clearance of prolactin- End-stage renal disease
- Big prolactin=macroprolactinemia (prolactin circulates in large aggregates)
Other - Pregnancy
- Hypothyroidism
- Cirrhosis
- Adrenal insufficiency
- Polycystic ovary syndrome (PCOS)
❍ What is the most common cause of mildly elevated prolactin levels?
Stress.
❍ What other causes of a mildly elevated prolactin level must be considered?
Recent meal, breast stimulation, coitus, exercise, or if the patient has just awakened.
❍ What is the predominant physiologic prolactin inhibitory factor?
Dopamine.
❍ What are other prolactin inhibitory factors?
Gonadotropin-releasing hormone (GnRH)-associated protein
GABA
❍ Name five prolactin releasing “factors.”
Serotonin
Thyrotropin-releasing hormone (TRH)
Vasoactive intestinal peptide (VIP)
Opioid peptides
Prolactin-releasing peptide (PRLrP)
Estrogens and the hormonal milieu of pregnancy
Growth hormone-releasing hormone (GHRH)
GnRH
❍ What is the most common pituitary tumor?
Prolactin-secreting adenoma.
❍ How does elevated prolactin cause amenorrhea?
Prolactin inhibits the pulsatile secretion of GnRH.