[Multiple pregnancies prevention in in vitro fertilization: limiting the number of transferred embryos to two maximum?].
The success of an IVF-programme is mainly linked to the number and quality of embryos transferred as well as women's age, but the incidence of obstetrics complications rises significantly with the number of fetuses. Reducing the number of embryos transferred is therefore recommended in order to avoid the medical, social and financial problems associated with multiple births. Present data suggest that, when at least three embryos of good quality are available, the pregnancy rate already reaches its maximum value when two embryos are transferred. A third one merely increases the number of triple pregnancies. Further studies are needed to conclude, especially in the cases of poor quality embryos.