Has oligomenorrhea a pathological meaning? The importance of this symptom in internal medicine

Background: Oligomenorrhea, defined as a menstrual cycle lasting 36 to 90 days, can be a normal condition in the first years after the menarche. When it persists or appears after a period of normal menstrual cycles, an underlying illness must be sought. Aim: To assess ovulation and causes of anovulatory cycles in women with oligomenorrhea, compared with causes of secondary amenorrhea. patients and methods: One hundred one women of less the 35 years old, presenting with oligomenorrhea persisting 5 years after menarche or lasting more than two years after a period of normal menstrual cycles, were studied. Ovulation was studied measuring serial plasma progesterone during normal or induced (with intramuscular progesterone) menstrual cycles. Results: Eighty nine percent of women had anovulatory oligomenorrhea. The main causes were polycystic ovarian disease in 51% and hypothalamic dysfunction in 31%. Thirty percent of women with secondary amenorrhea had polycystic ovarian disease and 14% had hyperprolactinemia. women older than 20 years old or with more than 10 years of gynecological age had a higher frequency of polycystic ovarian disease and a lower prevalence of hypothalamic dysfunction. Conclusions: There is a high frequency of anovulatory oligomenorrheas. Therefore, this symptom deserves a thorough endocrinological assessment to uncover underlying diseases. Special attention must be paid to polycystic ovary syndrome, due to its importance in internal medicine as a risk factor for myocardial infarction, high blood pressure, and type 2 diabetes mellitus.