The Potential Role of GnRH Agonists and Antagonists in Inducing Thyroid Physiopathological Changes During IVF

We conducted an observational cohort study to evaluate whether drugs used for hypothalamic inhibition may impact thyroid function of infertile women scheduled for fresh nondonor in vitro fertilization/intracytoplasmic sperm injection treatment. We considered eligible for inclusion in the study only women with normal thyroid function (serum thyroid-stimulating hormone [TSH] range: 0.2-4.0 mIU/L, serum thyroxin values: 9-22 pmol/L) and negative personal history for previous thyroid disorders. According to which protocols were implemented to gain hypothalamic inhibition, patients were assigned to group A (70 women treated by long gonadotropin-releasing hormone [GnRH] agonist protocol) or to group B (86 women treated by flexible GnRH antagonist protocol). Before initiating controlled ovarian stimulation (COS), both groups were further stratified into 4 subgroups: A1 (46 of the 70 women) and B1 (61 of the 86 women) in women with a baseline TSH value <2.5 mIU/L, whereas those with a baseline value ≥2.5 mIU/L were assigned to groups A2 (24 of the 70 women) and B2 (25 of the 86 women). Prior to initiating stimulation (T-0), 17-β-estradiol (E2) and TSH serum values were dosed in all women and repeated on T-5 (day 5 of COS) and subsequently every 2 days until T-ov-ind (ovulation induction day) and T-pick-up (oocytes retrieval day). In case of detection of TSH levels above the cutoff, patients were screened for thyroxin and thyroid autoantibody serum values. In group A, E2 at...
Source: Reproductive Sciences - Category: Reproduction Medicine Authors: Tags: Original Articles Source Type: research