Egg Quality, and How It’s Affected by Thyroid Hormones

Egg quality is one of the main factors we aim to ameliorate in PCOS, and new studies show a link between thyroid hormones, and healthy oocyte (egg) development.

In my practice, I treat many women who are contending with thyroid disorders. I’ve seen these conditions contribute consistenly to poor egg quality, subfertility, and miscarriage. The latter of these conditions is assumed  to occur because of the embryo’s dependence on its mother’s thyroid hormone for its own metabolism. Before the embryo’s 12th week, it’s unable to make its own thyroid hormones. As such, it’s wholly dependent on its mother for these crucial growth-supporting factors. 

There also appears to be a strong link between low egg count, premature menopause, and Hashimoto’s (Autoimmune) thyroiditis. It would appear that this link is related to thyroid and ovary cross-reactivity. Women with PCOS also tend to experience egg quality impairment, and this group commonly exhibits thyroid dysfunction as well.

A new study delved beyond autoimmune factors to look at how thyroid hormones themselves affect the growth and development of healthy eggs, and the production of female hormones. 

Researchers delved into in the direct impact of T3 and T4 hormones on ovarian follicle growth and development, as they produce the vast majority of key female sex hormones.
Read more about this study in the full post on the drfionand website here.