The growth of human preimplantation embryos in vitro
RG Edwards, JM Purdy, PC Steptoe… - American Journal of …, 1981 - Elsevier
The parameters of the growth of human embryos in vitro between fertilization and the
biastocyst are described. The data on the cleavage of embryos were subjected to statistical
analysis. All the pronucleate eggs examined had two pronuclei. There was no evidence of
any oocyte with three or more pronuclei, except in one examined 3 days after insemination,
which may have been degenerating. Most eggs which were unfertilized remained in
metaphase of the second meiotic division, with an extruded polar body. Spermatozoa were …
biastocyst are described. The data on the cleavage of embryos were subjected to statistical
analysis. All the pronucleate eggs examined had two pronuclei. There was no evidence of
any oocyte with three or more pronuclei, except in one examined 3 days after insemination,
which may have been degenerating. Most eggs which were unfertilized remained in
metaphase of the second meiotic division, with an extruded polar body. Spermatozoa were …