Levothyroxine in Women with Clinical Hypothyroidism Undergoing In-Vitro Fertilization: A Case Report

Abstract

Hypothyroidism is characterized by a high thyroid stimulating hormone (TSH) level and low thyroid hormones (T3 and/or T4). Abnormalities in ovulation, infertility, and recurrent pregnancy losses can arouse due to hypothyroidism. Pregnancy is a physiological status that mandates an increase in levothyroxine doses for euthyroid women with primary hypothyroidism. Serum levels of thyroid stimulating hormone can increase significantly during In-Vitro fertilization among women treated for hypothyroidism, and hypothyroidism that is either undiagnosed or under-treated can contribute to infertility and result in miscarriages. Throughout the literature, artificial pregnancies, In-Vitro fertilization (IVF) mainly, have required a more aggressive increase in the levothyroxine dose. Here, we report the case of a 40-year old hypothyroid woman with a history of nine abortions after IVF procedures who presented for treatment of her hypothyroidism. We present in details the modification process of her levothyroxine dose according to monthly TSH levels starting from her ninth miscarriage through her tenth IVF procedure and all throughout the pregnancy, until the successful delivery of a healthy baby.