Thyroid function (TSH)
Also written as TSH test
A blood test measuring thyroid stimulating hormone, used to check whether the thyroid gland is working within a normal range.
In plain English
It's a blood test that checks how well your thyroid gland is working, because an underactive or overactive thyroid can affect fertility.
Why it matters
Thyroid problems are common and treatable, so this is often one of the early tests done before or during fertility treatment.
Related terms
Guides that cover this
Written by patients, not clinicians. This page has not yet been reviewed by a named fertility professional, so it explains published guidance and points you to the original source instead of giving medical advice. It is not medical advice. Decisions about your treatment belong with your own clinic. Read our editorial policy and corrections policy.