High follicle-stimulating hormone increases aneuploidy in human oocytes matured in vitro

Objective To study the effect of FSH on the aneuploidy risk of human oocytes matured in vitro. Design Prospective study. Setting Hospital-based IVF center. Patient(s) Patients with male factor infertility undergoing intracytoplasmic sperm injection (ICSI) cycles. Intervention(s) Immature oocytes were put into five groups according to the FSH concentration (0, 5.5, 22, 100, and 2,000 ng/mL) in in vitro maturation (IVM) medium. Spindles were observed under a polarized microscope before polar body biopsy. Fixed polar bodies and corresponding oocytes were examined on chromosomes 13, 16, 18, 21, and 22 by fluorescence in situ hybridization. Oocytes matured in 5.5 and 2,000 ng/mL FSH were immunostained for tubulin and chromatin. Main Outcome Measure(s) Aneuploidy rate, spindle visualization rate, and spindle morphology. Result(s) The frequency rates of aneuploidy were 26.7%, 23.3%, 36.75%, 46.67%, and 63.3% in the five FSH groups, respectively. There was a significantly higher aneuploidy rate in oocytes matured in the 2,000 ng/mL FSH group. The spindle visualization rates assessed under PolScope were not significantly different between aneuploid and normal oocytes. There was no difference in spindle morphology between the 2,000 and 5.5 ng/mL FSH groups. Conclusion(s) High-concentration FSH in IVM medium significantly increased the first meiotic division error, resulting in more aneuploid oocytes during IVM.