- All women will have evidence of a prolactin related hormonal side effect (amenorrhea, oligomenorrhea or galactorrhea). This will be determined by patient report/history and medical record/clinician interview. Oligomenorrhea is defined as infrequent, irregularly timed episodic bleeding occurring at intervals of more than 35 days from the previous menstrual cycle and amenorrhea is defined as absence of menstruation for three menstrual cycles or 6 months (Berek et al. 2002). Galactorrhea is defined as lactation or copious milk secretion.