Are cumulus cells necessary for the spontaneous maturation of germinal vesicle-stage oocytes to metaphase II.
OBJECTIVE
In this study we investigated the need of the support from cumulus cells for germinal-vesicle (GV) oocytes collected from stimulated ovaries to complete their maturation to metaphase II (MII).


METHODS
We compared the maturation rate of GV oocytes after coculture with cumulus cells (study group) with their spontaneous maturation in culture medium alone (control group).


RESULTS
Sixty-four and nine-tenths percent of the GV oocytes matured to metaphase II in the coculture group, and of these, 43.5% gave normal 2pn zygotes following intracytoplasmic sperm injection (ICSI), while 73.8% of the GV oocytes spontaneously matured to the MII stage and 30% of these reached the zygote stage after ICSI.


CONCLUSIONS
It is probable that a follicular factor is responsible for this arrested maturation in the human and that maturation occurs spontaneously when the oocytes are separated from their follicular fluid environment after collection.
Department of Gynaecology and Obstetrics, Kantonsspital, Baden, Switzerland.
M
M
Häberle
P
P
Scheurer
K
K
Lauerer
M
M
Fischer
M K
MK
Hohl
D018929:Cell Culture Techniques / Q000379:methods; D002453:Cell Cycle; D002455:Cell Division; D018920:Coculture Techniques; D015925:Cryopreservation; D003470:Culture Media; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D015571:Follicular Fluid / Q000166:cytology*; D006801:Humans; D008297:Male; D008677:Metaphase; D009865:Oocytes / Q000166:cytology* / Q000502:physiology; D006080:Ovarian Follicle / Q000502:physiology*; D013084:Sperm-Ovum Interactions; D015053:Zygote / Q000166:cytology
D003470:Culture Media