Thyroid and Assisted Reproduction Technologies: A Brief Clinical Update with Recommendations for Practice

Area of Science:

• Reproductive Endocrinology
• Immunology
• Thyroidology

Background:

• Infertility affects a significant portion of women, often necessitating assisted reproduction technologies (ART).
• Thyroid autoimmunity (TAI), with or without hypothyroidism, is prevalent in females and frequently requires endocrine evaluation.

Purpose of the Study:

• To investigate the impact of thyroid autoimmunity (TAI) on outcomes for women undergoing assisted reproduction technologies (ART).
• To review the current literature on the association between TAI, subclinical hypothyroidism, and ART success rates.

Main Methods:

• Systematic review of studies published over the last 15 years.
• Analysis of data concerning primary outcomes (pregnancy rate, miscarriage, live births) and secondary outcomes (ovarian reserve, oocyte quality).

Main Results:

• Conflicting data exist regarding the association between infertility and TAI/subclinical hypothyroidism due to insufficient sample sizes.
• Current literature does not conclusively demonstrate a negative impact of TAI/subclinical hypothyroidism on pregnancy rates, miscarriage, or live births.
• Secondary outcomes, such as ovarian reserve and oocyte quality, appear to be negatively affected by TAI.

Conclusions:

• Controlled ovarian hyperstimulation (COH) can worsen thyroid function in patients with TAI.
• Patients with TAI undergoing ART are at increased risk of elevated TSH levels during treatment.
• A TSH level <2.5mIU/L is recommended before COH for thyroid antibody-positive patients, with strict monitoring and potential Levothyroxine (LT4) adjustment.