B. R. Angell1, R. J. Aitken1, P. F. A. Look2, M. A. Lumsden2, A. A. Templeton2. 1M.R.C. Reproductive Biology Unit, 37 Chalmers Street, Edinburgh EH3 9EW. 2Department of Obstetrics and Gynaecology, Centre for Reproductive Biology, 37 Chalmers Street, Edinburgh EH3 9EW
Information on the frequency of chromosome abnormalities in spontaneous abortions and in the live born population of man show that about 9 % of all clinically recognised pregnancies carry a chromosome abnormality. No data is available on the frequency of chromosome anomalies in the preimplantation stage in man although it is recognised that about 40 % of in vivo fertilized embryos are lost at this stage of pregnancy.
In vitro fertilization procedures have opened the way to examining the chromosomes of preimplantation embryos. From preliminary data in 10 cleaving embryos, seven have had a normal chromosome...
