Healthy live birth following embryo transfer of a blastocyst of tetrapronuclear (4PN) origin: a case report.

During IVF treatments, normal fertilization is generally evidenced by the appearance of two pronuclei, one arising from the oocyte and the other from the male gamete. Embryos derived from zygotes with a pronuclei number other than two are assumed to possess a ploidy abnormality and their transfer is usually avoided owing to increased risk of implantation failure, miscarriage, and molar pregnancies. Nonetheless, the inclusion of genotyping data in preimplantation genetic testing has revealed that a normal diploid configuration is possible in embryos deriving from zygotes with an abnormal pronuclei number such as tripronuclear and one pronucleus.