Multinucleation in cleavage stage embryos.

Background: The aim was to analyse multinucleation in relation to its incidence in time and in the population, and its correlation with clinical variables, with other morphological characteristics and with the implantation rate of cleavage stage embryos.

Methods: Retrospective analysis of 10 388 cleaved embryos from 1395 consecutive IVF/ICSI cycles in 700 patients between January 1, 1999 and June 30, 2002.

Results: Multinucleation was observed in 3491 (33.

Elective single day 3 embryo transfer halves the twinning rate without decrease in the ongoing pregnancy rate of an IVF/ICSI programme.

Background: Data on the effect of elective single embryo transfer (eSET) on the total and multiple pregnancy rates of an IVF/ICSI programme are reported.

Methods And Results: A retrospective cohort analysis of eSET was carried out over a 4 year period. A total of 1559 cycles resulted in 1464 transfers; 299 transfers of one top quality embryo (20.