The maturity of human cumulus-free oocytes is positively related to blastocyst development and viability.
OBJECTIVE
We investigated whether the human oocyte maturity at the removal of cumulus/corona cells affects the embryo outcome in vitro.


METHODS
A total of 620 oocytes, which subsequently underwent blastocyst culture, were included in this analysis. Oocytes that were in prophase or Metaphase I of meiosis at the removal of cumulus/corona cells were in Group II. Oocytes that were in Metaphase II at the removal of cumulus/corona cells were in Group I.


RESULTS
Group I oocytes yielded the highest fertilization rates (96.3% vs. 77.1%, P < 0.001). The incidence of Group II oocytes developing to the blastocyst stage was significantly less than from Group I oocytes (38.1% vs. 86.1%, P < 0.001). The percentage of top-scoring blastocysts from Group I oocytes was higher than that of Group II oocytes (95.4% vs. 76.2%, P < 0.001).


CONCLUSIONS
Oocyte maturity at the removal of cumulus/corona cells needs to be considered in selecting good quality blastocysts for embryo transfer.
Huang
Fu-Jen
FJ
Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Kaohsiung, Taiwan. huangfj@seed.net.tw
Huang
Hsuan-Wei
HW
Lan
Kuo-Chung
KC
Kung
Fu-Tsai
FT
Lin
Yi-Chi
YC
Chang
Hsueh-Wen
HW
Chang
Shiuh-Young
SY
D000328:Adult; D001755:Blastocyst / Q000166:cytology / Q000502:physiology*; D018929:Cell Culture Techniques / Q000379:methods; D002470:Cell Survival; D005260:Female; D006801:Humans; D008423:Maternal Age; D008540:Meiosis / Q000502:physiology; D008677:Metaphase / Q000502:physiology; D009865:Oocytes / Q000166:cytology* / Q000502:physiology*; D020554:Sperm Injections, Intracytoplasmic