label: Formation of multiple pronuclei during fertilization
label_lc: formation of multiple pronuclei during fertilization
description: "Pronuclei formation is a critical process during fertilization. Normally, there are two pronuclei (2PN), including the paternal pronucleus and the maternal pronucleus, in the zygote after fertilization. It is generally accepted that multiple pronuclei (MPN) formation is due to the abnormal extrusion of the second polar body or to abnormal fertilization with multiple sperm. The MPN therefore can cause infertility and recurrent failure of IVF/ICSI."