Levothyroxine for a high-normal TSH in unexplained infertility.

Area of Science:

• Endocrinology
• Reproductive Medicine
• Clinical Research

Background:

• Unexplained infertility impacts a significant portion of infertile couples.
• Elevated high-normal thyroid-stimulating hormone (TSH) levels (2.5-5 mIU/L) are observed more frequently in women with unexplained infertility.
• Clinical guidelines differ on treating high-normal TSH in women attempting conception due to unknown levothyroxine effects.

Purpose of the Study:

• To evaluate the impact of levothyroxine treatment on conception and live birth rates in women with unexplained infertility and high-normal TSH levels.
• To compare outcomes between women treated with levothyroxine and those who were not.

Main Methods:

• A retrospective study involving 96 women with unexplained infertility and high-normal TSH levels.
• Participants were divided into two groups: those prescribed levothyroxine (n=31) and those not prescribed (n=65).
• Conception and live birth rates were assessed for both groups.

Main Results:

• The levothyroxine group exhibited a 100% conception rate versus 90% in the untreated group (p<0.05, adjusted for age).
• The live birth rate was lower in the levothyroxine group (63%) compared to the untreated group (84%) (p=0.035, adjusted for TSH).
• These results are limited by a small sample size.

Conclusions:

• Levothyroxine treatment in women with unexplained infertility and high-normal TSH may increase conception rates but potentially decrease live birth rates.
• The observed differences suggest a need for caution and further investigation.
• Prospective, randomized studies are essential to definitively determine the benefits of levothyroxine treatment in this patient population.