Fertil Steril. 2016 May; 105(5): 1307-1313
Zachary P. Demko, Ph.D.,a Alexander L. Simon, B.S.,a Rajiv C. McCoy, Ph.D.,b Dmitri A. Petrov, Ph.D.,c and Matthew Rabinowitz, Ph.D. Natera, Inc., San Carlos, California; b Department of Genome Sciences, University of Washington, Seattle, Washington; and c Department of Biology, Stanford University, Stanford, California
Abnormal chromosome number is very common in human embryos and is responsible for IVF failures and miscarriages. ZP Demko et al. published in Fertility Sterility a study of preimplantation genetic screening of embryos from different IVF clinics. The significance of the study comes from the large number of embryos examined from different IVF clinics and the comprehensive technique they used such as single nucleotide polymorphism (SNP) arrays for all 24 chromosomes.
The mean percentage of embryos with normal chromosome numbers (euploid) was about 60 %, steady from 25 to 35 years of maternal age. But after 35 years there was a steep decline reaching a small single digit number and frequently zero at the age of 45. This is crucial information to advice, explain and set realistic expectation during IVF treatments.