New Belgian legislation regarding the limitation of transferable embryos in in vitro fertilization cycles does not significantly influence the pregnancy rate but reduces the multiple pregnancy rate in a threefold way in the Leuven University Fertility Center.

After the introduction of new Belgian legislation limiting the number of transferable embryos to prevent multiple pregnancies after assisted reproductive technology, the implantation rate per embryo remained stable at 26% and the clinical pregnancy rate per embryo transfer did not change significantly (37.5% before and 32.5% after legislation), whereas the multiple pregnancy rate per clinical pregnancy decreased threefold from 25.9% to 8.0%) in the Leuven University Fertility Center.