Serum gonadotropin and prolactin levels in females with primary infertility and thyroid dysfunction in North Indian population

Adequate levels of circulating thyroid hormones are of primary importance for normal reproductive function. Patients with subclinical hypothyroidism have no symptoms or very few symptoms related to thyroid disease, but may have adverse outcome on fertility but are not referred to infertility clinics. Galactorrhea and hyperprolactinemia patients may have primary hypothyroidism. The aim of this study was to evaluate if thyroid dysfunction leads to any alteration in serum gonadotropin and prolactin levels contributing towards infertility. This case control study was performed in 256 females in a tertiary care hospital.Serum TSH, fT4 and fT3, LH, FSH and prolactin levels were assayed using fully automated chemiluminescent immunoassay Analyzer Access 2 by Beckman and Coulter (USA). Serum LH, FSH levels were significantly low and serum prolactin levels were significantly high in patients with infertility and hypothyroidism. Serum LH, FSH levels were significantly high in infertile females with hyperthyroidism whereas serum prolactin levels were low but not significantly different in these patients. Thyroid disorders have a great impact on fertility in females. Fertility improves when euthyroidism is restored. It has been suggested that normal gonadotropin and thyroid function tests are necessary to achieve maximum fertilization rate and blastocyst development. Thyrotoxicosis in women has been linked with reduced fertility but the mechanism for the same has not been elucidated clearly. We suggest screening of thyroid hormone in all the females with infertility.