Fatemeh Montazeri - Department of Genetics, Faculty of Sciences, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Ali Mohammad Foroughmand - Yazd Institute of Reproductive Sciences, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Seyed Mehdi Kalantar - Department of Genetics, Faculty of Sciences, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Abbas Aflatoonian - Yazd Institute of Reproductive Sciences, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
Ali Mohammad Khalili - Yazd Institute of Reproductive Sciences, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.

Background and Aims: One of the major subjects for improving in vitro fertilization (IVF) outcome is the quantity and quality of retrieved oocytes. In vitro maturation (IVM) provides an opportunity for using immature oocytes routinely discarded in clinics. This study aimed at evaluating the quality of embryos derived from in vivo and rescue in vitro matured oocytes. Materials and Methods: Totally, ۴۶۲ immature oocytes as cases and ۴۶۶ mature (MII) oocytes as controls were included for study of their developmental competence. Oocytes underwent intracytoplasmic sperm injection insemination and then denuded oocytes were microscopically assessed regarding cytoplasmic and nuclear maturity and quality. Results: The morphological assessments showed fertilization rate of ۶۰.۹ and ۶۱.۴%, the embryo formation rate of ۸۶.۷% and ۹۰.۹% and arresting rate of ۲۷.۳% and ۲۵.۶% for the case and control oocytes, respectively. Evaluating embryo quality in the cleavage stage indicated that ۶۳% of the embryos in the case group and ۶۸% of the embryos in the control group were of good quality. There was no significant difference between fertility rate and arresting rate of oocytes matured in both groups, although the embryo formation rate and the quality of embryos differed significantly. Conclusions: Our findings suggest that IVM is a valuable and practical option for patients who had to cancel IVF treatment cycles because of severe responses or resistance to routine hormonal therapies or those with low functional ovarian reserve.

Developmental competence, Embryo, In vitro fertilization, In vitro maturation, Oocyte