Impact of a restriction in the number of embryos transferred on the multiple pregnancy rate.

Objective: To study the impact of the introduction of reimbursement of in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) laboratory costs in Belgium which is linked to an embryo transfer strategy leading to prevention of multiple pregnancies. The impact on the incidence of multiple and twin pregnancy rate as well as on ongoing pregnancy rate in our centre is calculated.

Study Design: Observational cohort study of all patients in the first year (July 1, 2003-June 30, 2004) since the implementation of the law and comparison of ongoing pregnancy rate and multiple pregnancy rate of our centre with Belgian data.

Singleton pregnancies are as affected by ovarian hyperstimulation syndrome as twin pregnancies.

The incidence of ovarian hyperstimulation syndrome (OHSS) did not decrease during the 5 years in which single-embryo transfer was introduced; OHSS is not more frequent in twin than in singleton pregnancies.

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.