Hello, It is indeed a cause for concern if you have hyperprolactinemia and this can cause infertility and hence, needs to be corrected. Treatment of hypothyroidism is not responsible for this condition; in fact, the hormonal defect could be an associated factor and you may perhaps need further investigation and treatment for multiple hormone imbalances that could lead to infertility. Hyperprolactinemia can be simultaneously corrected through medication once organic causes are excluded. Hope this helps.