Prevalence of hyperprolactinaemia in female premenopausal blood donors.

OBJECTIVE: The prevalence of asymptomatic hyperprolactinaemia has been widely studied in certain populations such as antipsychotic drugs users, infertile women or patients with primary hypothyroidism, but data on the prevalence of hyperprolactinaemia and macroprolactinaemia in the healthy population are very scarce in the literature. We aimed to obtain an unbiased estimation of the prevalence in premenopausal women of: (i) hyperprolactinaemia and (ii) its aetiology, including macroprolactinaemia and stress-related hyperprolactinaemia, while considering simultaneously the use of hormonal contraceptives. DESIGN: Prevalence survey. SUBJECTS: Three-hundred and ninety-three consecutive premenopausal women reporting spontaneously for blood donation. MEASUREMENTS: We performed an exhaustive clinical history and physical examination, establishing the presence of hirsutism, acne, alopecia, menstrual dysfunction and reproductive history. We also measured serum prolactin (PRL) (ruling out macroprolactinaemia when indicated), thyrotrophin, total testosterone, androstendione, sex hormone binding globulin and dehydroepiandrosterone sulphate concentrations. RESULTS: Serum PRL concentrations were increased in 16 of 393 women (4·1% prevalence, 95% CI: 2·1-6·0). The prevalence of macroprolactinaemia was 0·6% (95% CI: 0-1) in the total female blood donor population and was 12·5% (95% CI: 6-31) among hyperprolactinaemic patients. The remaining hyperprolactinaemic women had stress-related hyperprolactinaemia as the more likely aetiology. Finally, the frequency of hyperprolactinaemia was similar in users and nonusers of hormonal contraceptives (4·5% and 3·9% respectively, P = 0·209). CONCLUSIONS: The prevalence of hyperprolactinaemia in healthy female blood donors is low and is not influenced by the use of hormonal contraceptives. Pathological causes are very rare with stress-related hyperprolactinaemia and macroprolactinaemia being the most frequent causes of hyperprolactinaemia in these women.