Objectives: The aim of this study was to assess relationship between CGG repeat lengths and ovarian reserve and response to controlled ovarian stimulation (COH).
Material and methods: This prospective cohort study was carried out on patients (n = 49) who were admitted to the in vitro fertilization (IVF) clinic of the Zeynep Kamil Women's and Children's Diseases Training and Research Hospital, University of Health Sciences. Women under 40 years of age with premature ovarian insufficiency underwent genetic analysis to determine CGG repeat lengths. Ovarian reserve was assessed for each participant and participants underwent ovarian hyperstimulation and intracytoplasmic sperm injection (ICSI) cycle. Relationships between ovarian reserve, cycle outcome and CGG repeat lengths were assessed. Variables including fertility assessment including ovarian reserve tests (Follicle stimulating hormone (FSH), Luteinizing hormone (LH), Estradiol (E2), Prolactin (PRL), Thyroid stimulating hormone (TSH), Antimullerian hormone (AMH), antral follicle count (AFC) tests) and some IVF cycle characteristics were assessed in relation to number of CGG repeat numbers.
Results: None of the ovarian reserve tests and cycle characteristics was found to be correlated with CGG repeat lengths. Comparison of ovarian reserve tests and cycle characteristics revealed no difference between groups of women with CGG repeat length > 55 and CGG repeat length ≤ 55. Antimullerian hormone (AMH) was a significant predictor for cycle cancellation (AUC = 0.779, P = 0.008). AMH level > 0.035 was found to be the optimal cut off value to predict cycles reaching to embryo transfer with 71% sensitivity and 85% specificity. The rate of cycle cancellation was 71% in cases with AMH ≤ 0.035 whereas it was 20% in cases with AMH > 0.035 (p = 0.001). No difference was determined between groups with and without cycle cancellation in terms of CGG repeat lengths (55.3 vs. 53.9, p = 0.769). Among cycles reaching to embryo transfer stage, 3 (13.6%) pregnancies were achieved.
Conclusions: Our data showed no relationship between CGG repeat lengths and ovarian reserve and response to controlled ovarian stimulation. This data also showed that no clinical difference between FMR gene mutation related POI and other etiologies.
Keywords: CGG repeat length; ICSI; pragile X; premature ovarian insufficiency.