Thyroid function in 195 infertile patients undergoing assisted reproduction.

There is a known association between hypothyroidism and decreased fertility, which is mainly associated with ovulatory disturbances. According to literature data, women who require treatment with levothyroxine have a twofold increased risk of primary ovulatory infertility and in infertile women the prevalence of those positive for thyroid peroxidase antibodies is higher than in control group. Nowadays, infertile couples undergo assisted reproduction technologies (ART), including in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). The pregnancy rate of women undergoing ART appears to be significantly lower in subjects who are positive for organ-specific autoantibodies such as antithyroid and antiovarian antibodies. We retrospectively evaluated 195 procedures of assisted reproduction technologies performed at Fertility Center of Sapienza University of Rome, for which thyroid function data were recorded (including serum TSH and free thyroxine). The mean age of women treated was 37.39 (range 24-48). We considered as endpoints the number of oocytes retrieved, the number and grade of embryos transferred after fertilization , and the number of clinical pregnancies. In 77 procedures, the presence of thyroid peroxidase antibodies was evaluated, and thyroid autoimmunity was present in 9 cases. No significant differences were recorded in the number of oocytes retrieved and in the number of embryos transferred between the two groups. No pregnancy occurred in women with thyroid autoimmunity. 34 procedures were performed during treatment with levothyroxine. No significant differences were recorded in the number of oocytes retrieved, in the number of embryos transferred between the two groups and in the pregnancy rate. These data suggests that, in women undergoing ART, the ovarian response to stimulation and the pregnancy rate seems to be not influenced by either the presence of thyroid peroxidase antibodies or treatment with levothyroxine. Further studies are – however – in progress