In plain words
TSH stands for thyroid-stimulating hormone. It is made by the pituitary gland in the brain and tells the thyroid gland how much hormone to make. When thyroid hormone is low, TSH tends to rise. When it is high, TSH tends to fall. A TSH blood test is usually the first check for thyroid problems in pregnancy and after birth. It is often read together with free T4, which measures the thyroid hormone itself. Ranges shift in pregnancy, so the result is compared with the pregnancy range. A raised or low TSH is a reason to talk with your provider, not a diagnosis on its own.
The deeper version
TSH is secreted by thyrotrophs in response to hypothalamic TRH and is suppressed by free T4 and T3 through negative feedback. In pregnancy, stimulates the TSH receptor in early gestation, lowering TSH in the first trimester; trimester-specific reference ranges are recommended by the ATA (2017) and the Endocrine Society. typically produces a transient thyrotoxic phase, then a hypothyroid phase at about 3 to 12 months postpartum, and TSH is the most sensitive screening measure. Controversy remains over universal screening in pregnancy, and the ATA found insufficient evidence for or against it while supporting testing of women with risk factors.
Where it comes up
- Postpartum thyroid problemsPostpartum: Your Body
- Forgetfulness and brain fogPregnancy: Mind and Life
- Anemia and exhaustion after birthPostpartum: Your Body
- Postpartum depressionPostpartum: Mind
What mothers here say about TSH
No one has posted under this term yet.
Sources
- American Thyroid Association — Guidelines for the Diagnosis and Management of Thyroid Disease During Pregnancy and the Postpartum, 2017
- Alexander EK et al. — 2017 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and the Postpartum. Thyroid 2017