Does having an underactive thyroid reduce male fertility?

Fertility: Yes it can affect the quality of the sperm and thereby affect fertility.

Possible: If the thyroid problem is treated appropriately then there should be no major effect. Untreated thyroid disease can affect sperm production so definitely it should be treated appropriately.

It can: Unstable thyroid disease (either low or high, underactive or overactive) can affect male hormone balance and therefore fertility. Once a stable thyroid treatment has been ongoing for 6 months or more, there should be no more effect on male fertility. Btw: thyroid disease is the cause of male infertility in.