Menstruation disorders and its frequency in female patients with thyroi̇d dysfunction

Thyroid hormones play an important role in achieving and maintaining of reproductive functions. Thyroid dysfunction affects the menstrual cycle and lead to menstrual irregularity. We prospectively investigated untreated female patients who attended the Endocrinology and İnternal Medicine outpatient clinics of our hospital. All the patients were in the reproductive age, those newly diagnosed with thyroid dysfunction. One hundred and eight female who had normal routine laboratory and imaging studies were included in the study as healthy control group. In all of the participants TSH, fT3, fT4, anti-Tg, anti-TPO were measured. Thyroid Doppler ultrasonography (USG) was performed in all of them. Thyroid functional status was determined by measurement of TSH, fT3 fT4. Patients were subdivided into the following groups: overt hypothyroidism (54 patient), subclinical hypothyroidism (106 patient), overt hyperthroidism (50 patient), subclinical hyperthyroidism (55 patient), euthyroid patients (Hashimoto's thyroiditis + nodular goiter) (220 patient). Totally 108 healty and 485 patient were included in the study. The prevalence of menstrual disturbances, including secondary amenorrhea, hypomenorrhea, oligomenorrhea, hypermenorrhea, polymenorrhea menorrhagia, metrorrhagia and menometrorrhagia were prospectively examined in patients and compared with those in healthy controls. Among patients with overt hypothyroidism; the most frequent menstrual disorders were hypermenorrhea, menorrhagia, oligomenorrhea and polymenorrhea. Hypermenorrhoea prevalence was significantly higher (%33.3) when compared to controls (%5.6) (p<0.05). Menstrual disturbances were also analyzed in relation to the severity of hypothyroidism. Severe hypothyroidism group (TSH > 50 μIU/ml) compared with mild hypothyroidism group (TSH 5-10 μIU/ml) (%16.5); hypermenorrhoea prevalence was statistically significant in severe group (%35), (p<0.05). The prevalence of any menstrual disturbances was never significantly higher than that of healthy controls in the other thyroid dysfunction groups. It is well known that thyroid function not only influences menstrual cycle but also affects reproductive activity, fertility and pregnancy outcome. Therefore early recognition and treatment of thyroid dysfunction is important.