Gonadotropin levels in hypothyroid women of reproductive age group

To study serum gonadotropin (FSH, LH) levels in cases of subclinical and overt hypothyroid women in reproductive age group.

Female patients of reproductive age group attending thyroid clinic of Acharya Vinoba Bhave Hospital were included in the study. Detail menstrual history was taken, and serum FSH and LH levels were estimated by radio immuno assay method.

Eighty patients were included in the study, out of whom 46 (57.5%) had subclinical hypothyroidism and 34 (42.5%) had overt hypothyroidism. In subclinical hypothyroidism group the menstrual dysfunction which dominated in our study was oligomenorrhea (28.2%) followed by menorrhagia (17.39%). 39.13% had normal menstruation. In overt hypothyroidism group again it was oligomenorrhoea (23.5%) which was the principal menstrual abnormality followed by menorrhagia (17.64%). The percentage of females with normal menstruation was 47.05%. The levels of serum FSH and LH were significantly low in cases of both subclinical and overt hypothyroid women. They were significantly low when done between day 2 and 5 of the cycle.

Hypothyroidism decreases levels of serum FSH and serum LH. Subclinical hypothyroidism is one of the major etiological factors of infertility. Autoantibodies against thyroid should be searched for in cases of female patients with infertility.