FLUORESCENT IN-SITU HYBRIDIZATION ANALYSIS OF CHROMOSOMALLY NORMAL GAMETES AND ABNORMAL ARRESTED EMBRYOS

Objective: The purpose of the present study was to investigate if the arrested embryos from a couple with several previously failed IVF trea tments were chromosomally normal, Probes for chromosomes X, Y and 18 w ere used. Results: A couple had undergone 7 in vitro fertilization tre atments over a 21/2-year period without achieving a pregnancy. In each cycle, where fertilization was obtained, the development of the embry os was arrested, Fluorescent in situ hybridization probes for chromoso mes X and Y (and 18) was carried out on gametes and on embryos in 2 se parate cycles. Sperm and oocytes were normally haploid XO or YO. The n uclei of the blastomeres were fragmented and mosaic for X or Y, or mon osomic XO, despite the fact that 2 pronuclei had been assessed on day I following intmcyroplasmic sperm injection. Conclusion: Chromosomally normal gametes can result in abnormal embryos manifested by arrested development and unexplained infertility.