In vitro fertilization outcomes in treated hypothyroidism

Area of Science:

• Reproductive Endocrinology
• Infertility Research
• Thyroid Disease Management

Background:

• Hypothyroidism is linked to poorer pregnancy outcomes in women undergoing in vitro fertilization (IVF).
• The extent to which levothyroxine treatment mitigates these risks requires further clarification.
• It is uncertain if levothyroxine fully counteracts hypothyroidism's negative effects on IVF success.

Purpose of the Study:

• To determine the impact of levothyroxine treatment on pregnancy outcomes in women with hypothyroidism undergoing IVF-intracytoplasmic sperm injection (ICSI).
• To compare IVF-ICSI cycle outcomes between women with treated hypothyroidism and age-matched euthyroid controls.
• To assess if levothyroxine effectively overcomes the adverse effects of hypothyroidism on fertility treatments.

Main Methods:

• Retrospective review of IVF-ICSI cycles over 3 years.
• Inclusion criteria: clinical or subclinical hypothyroidism treated with levothyroxine (cases) and age-matched euthyroid women (controls).
• Exclusion criteria: serum thyrotropin levels >2.5 mIU/L in both groups.

Main Results:

• No significant differences in clinical pregnancy, implantation, or live birth rates between treated hypothyroidism cases and controls.
• Slightly higher rates of cycle cancellation for poor response and longer stimulation duration in the hypothyroidism group.
• Higher proportion of women with treated hypothyroidism failed to obtain viable embryos and had lower fertilization rates.

Conclusions:

• Adequately treated hypothyroidism (TSH ≤2.5 mIU/L) with levothyroxine does not significantly hinder IVF-ICSI outcomes.
• Key reproductive metrics such as pregnancy, implantation, and delivery rates were comparable between groups.
• Levothyroxine treatment appears to effectively mitigate the negative impact of hypothyroidism on IVF success.