The effect of immature oocytes quantity on the rates of oocytes maturity and morphology, fertilization, and embryo development in ICSI cycles.
OBJECTIVE
The goal was to evaluate the role of the number of retrieved immature oocytes on mature oocyte counts and morphology, and also the rates of fertilization and embryo development in ICSI cycles.


METHODS
101 ICSI cycles were included in this prospective evaluation. Patients were divided into 2 groups of A (≤ 2 immature oocytes) and B (> 2 immature oocytes). In sub-analysis, the impacts of the number of GV and MI oocytes were assessed on the rates of fertilization and embryo development. Also, correlations between the numbers of immature and mature oocytes, as well as maternal age between two groups were analyzed. Assessments of oocyte morphology, fertilization, embryo quality and development were done accordingly.


RESULTS
There was no correlation between the immature oocytes quantity with the number of mature ones. There were insignificant differences for embryo development between two groups, but fertilization rate was higher in group A (P = 0.03). In sub-analysis, insignificant differences were observed between two groups of ≤ and >2 GV and MI oocytes for rates of fertilization and embryo development. Also, the rates of clinical pregnancy and delivery were insignificant between groups. The rate of morphologically abnormal oocytes had no significant difference between two groups, except for wide perivitelline space (PVS) which was higher in group A (P = 0.03). There was no significant difference for maternal age between two groups.


CONCLUSIONS
In cases with few retrieved immature oocytes, rates of fertilization and incidence of wide PVS may increase, although immature oocytes may not have any negative impacts on early embryo development, or the rates on number of mature oocytes.
Yazd Institute for Reproductive Sciences, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. ihalvaei@gmail.com
Iman
I
Halvaei
Mohammad
M
Ali Khalili
Mohammad Hossein
MH
Razi
Stefania A
SA
Nottola
D000328:Adult; D002452:Cell Count; D048430:Cell Shape; D004624:Embryo Transfer / Q000379:methods; D047108:Embryonic Development; D005260:Female; D005306:Fertilization; D006801:Humans; D008423:Maternal Age; D008677:Metaphase; D054315:Oocyte Retrieval / Q000379:methods; D009865:Oocytes / Q000254:growth & development / Q000502:physiology*; D011247:Pregnancy; D011446:Prospective Studies; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods*; D055815:Young Adult