Myths vs facts: TSH and fertility

Myths vs Facts: TSH and Fertility Myth: A TSH level above 2.5 mIU/L causes infertility. Fact: TSH is an important marker but not the sole determinant. Many women with TSH >2.5 conceive naturally. The American Thyroid Association suggests a target TSH <2.5 for women planning pregnancy, but this is a precautionary recommendation, not a strict cutoff. Levels above 4.0 warrant further evaluation. Myth: Only TSH matters for thyroid-related fertility issues. Fact: Free T3, free T4, thyroid antibodies (TPO, Tg), and overall hormonal balance (estradiol, progesterone, FSH, LH) also play critical roles. A single TSH value provides incomplete information. Myth: Any elevated TSH requires immediate levothyroxine treatment. Fact: For subclinical hypothyroidism (TSH 2.5–4.0) in women trying to conceive, treatment is often considered but evidence is mixed. The decision should be individualized with a physician. Conclusion: TSH is a useful screening tool but not a standalone fertility predictor. A comprehensive hormone panel (like MyBody-X) can offer insights but does not replace clinical diagnosis. Evidence: practice/guidelines.