Use of metaphase I oocytes matured in vitro is associated with embryo multinucleation

Use of MI oocytes matured in vitro during routine ICSI is associated with multinucleation, poorer embryo quality, and lower clinical pregnancy and implantation rates.

Like Comment


Sabrina De Vincentiis, M.S., Evelyn De Martino, M.S., Mariano G. Buffone, Ph.D., Santiago Brugo-Olmedo, M.D.

Volume 99, Issue 2, Pages 414-421.e4, February 2013



To evaluate the impact of oocyte maturational stage at retrieval on embryo multinucleation.


Retrospective study.


Private institution for assisted reproduction.


A total of 412 patients undergoing 500 ICSI cycles between August 2006 and September 2010.


Routine ICSI laboratory procedures.

Main outcome measures:

Normal and abnormal fertilization; embryo development; arrest at pronuclear stage; failure to undergo first mitotic division; presence of embryo multinucleation; embryo quality; pregnancy, implantation and miscarriage rates.


A significantly lower percentage of multinucleation was found in embryos originating from MII oocytes when compared with MI-II and MI derived ones. Significantly less multinucleated cells per embryo were observed in MII derived ones. Clinical pregnancy and implantation rates were significantly higher when only embryos derived from MII oocytes were transferred.


Embryo multinucleation rate increases when in vitro matured (2-5 hours incubation) metaphase I (MI-II) oocytes were used instead of in vivo matured ones in ICSI. Furthermore, all other ICSI outcome parameters are also compromised. The use of donated gametes does not modify these results.

Read the full text at:

Fertility and Sterility

Editorial Office, American Society for Reproductive Medicine

Fertility and Sterility® is an international journal for obstetricians, gynecologists, reproductive endocrinologists, urologists, basic scientists and others who treat and investigate problems of infertility and human reproductive disorders.