Sexual differentiation and preimplantation cell growth.
Growth rates of human preimplantation embryos fertilized in vitro were assessed and compared to the sex of the pregnancy outcome. The likelihood of a liveborn male was significantly greater than that of a female if the mean number of cells/embryo was four or greater at the scheduled time of transfer (odds ratio of 6:1). This finding suggested that the Y chromosome expresses factors which influence embryonic growth rates immediately after fertilization.
Pergament
E
E
Department of Obstetrics and Gynecology, Northwestern University Medical School, Chicago, IL.
Fiddler
M
M
Cho
N
N
Johnson
D
D
Holmgren
W J
WJ
D001755:Blastocyst / Q000166:cytology*; D002452:Cell Count; D002455:Cell Division; D004624:Embryo Transfer; D005314:Embryonic and Fetal Development; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D066298:In Vitro Techniques; D007246:Infertility / Q000628:therapy; D008297:Male; D011247:Pregnancy; D012733:Sex Differentiation; D012744:Sex Ratio; D013997:Time Factors; D014998:Y Chromosome