• Credits

  • Section Writer: Dr. Om J Lakhani
  • Section Editor: Dr. Om J Lakhani

• Q. Is there a link between thyroid dysfunction and infertility?

  • Yes
  • Current evidence suggests a definite link between over thyroid dysfunction (hyperthyroidism and hypothyroidism) and infertility and substantial improvement in fertility with treatment.

• Q. Summarize the approach to a woman with thyroid dysfunction and having a history of recurrent first-trimester abortion?

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• Q. Summarize the approach to Hypothyroidism and Female infertility
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• Q. Summarize the guidelines for Euthyroid women with Anti TPO positivity and infertility?
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• Q. Summarize the evidence available for Anti TPO positivity and fertility outcomes

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• Q. Is it true that women with PCOS are more likely to have anti-TPO antibody-positive?

  • Yes

• Q. Is it true that women with Anti TPO positive with or without TSH elevation are more likely to be infertile?

  • Limited evidence does suggest that women with female factor infertility are more likely to have TPO antibody positive compared to age-matched women who are not infertile.

• Q. What are the potential mechanisms linking Anti TPO positivity and infertility?

  • T cell abnormality
  • Hyperactivity and elevated mass of natural killer cells
  • Polyclonal B cell activation and non-organ-specific autoantibodies
  • Cross-reactivity
  • Vitamin D deficiency
  • Concurrent autoimmunity (i.e., endometriosis)
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• Q. Should all women with infertility undergo thyroid function testing?

  • Yes.

• Q. Is LT4 treatment recommended in women with subclinical hypothyroidism with anti-TPO negative who have infertility but not planned for ART?

  • There is insufficient evidence for or against using LT4 in this group of patients.

• Q. A woman is to undergo ART and have subclinical hypothyroidism with a TSH of 6.0 mU/l. Would you treat this woman?

  • Yes
  • The guidelines suggest that subclinical hypothyroidism in women who are to undergo ART should be treated.
  • The target for TSH is <2.5.

- Clinicalpearl

- Subclinical hypothyroidism (with an anti-TPO negative), with infertility:
- Those not undergoing ART- insufficient evidence for or against to treat.
- Those undergoing ART- treat and keep TSH <2.5 mU/l (Strong recommendation)

• Q. What about anti-TPO-positive women with euthyroidism undergoing ART?
  • The guidelines recommend that there is insufficient evidence to suggest for or against treatment in such a scenario; however, the benefits compared to harm are less, so giving a small dose of LT4 in a dose of 25-50 mcg/day may not be harmful.

- Clinicalpearl

- Subclinical hypothyroidism and ART:
- Subclinical hypothyroidism and ART with or without anti-TPO positive – treat (strong recommendation)
- Euthyroidism with Anti TPO positive undergoing ART –consider treatment with LT4 25-50 mcg to improve ART outcomes (Weak recommendation)

• Q. Does ovulation induction (ovarian stimulation impact thyroid function test)?

  • Physiologically, it is prudent to understand that ovarian hyperstimulation or ovulation induction may impact thyroid function
  • HCG, which is used here, may act on TSH receptors and increase thyroid hormones, while estrogen, which is produced in excess, may increase TBG and reduce free thyroid hormone.
  • Hence the impact of this is opposing and challenging to judge, but it does affect thyroid function.

• Q. What are the recommendations as far ovulation induction is concerned?

  • If a thyroid function test is done, then it must be done either before or 2 weeks after ovulation induction, since drugs used here may interfere with thyroid function test
  • If a woman becomes pregnant with ovulation induction – then do a thyroid function and treat as per the guidelines.
  • If the woman does not become pregnant, repeat the test after 2-4 weeks when levels may normalize.

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