The frequency of chromosome anomalies in human unfertilized oocytes and uncleaved zygotes after insemination in vitro.
Data on first trimester human abortions have shown chromosome aberrations in approximately 50% of the cases, most of which were trisomies. More than 80% of these trisomies have been attributed to an error in the oocyte. In this study we investigated the frequency of chromosome anomalies in 44 human unfertilized oocytes and 13 uncleaved zygotes after insemination in vitro. The oocytes were aspirated from preovulatory follicles in parous volunteer donors and patients participating in an embryo replacement programme. Thirty cases could be analysed, 18 of which (60%) carried a chromosome abnormality. There were two hyperhaploidies (6.7%), four hypohaploidies (13.3%), three polyploidies (10%), six with structural aberrations (20%) and five diploidies (16.7%). The incidence of these abnormalities, except for the structural anomalies, was similar to that reported previously. The higher frequency of structural aberrations in the present study may be related to delayed cytogenetic analysis for up to 48 h after insemination.
Papadopoulos
G
G
Department of Obstetrics and Gynaecology, University of Aberdeen, Foresterhill, UK.
Randall
J
J
Templeton
A A
AA
D000022:Abortion, Spontaneous / Q000235:genetics; D002869:Chromosome Aberrations; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007621:Karyotyping; D008540:Meiosis; D009865:Oocytes / Q000648:ultrastructure*; D011247:Pregnancy; D015053:Zygote / Q000648:ultrastructure*