Lack of correlation between oocyte-corona-cumulus complex morphology and nuclear maturity of oocytes collected in stimulated cycles for intracytoplasmic sperm injection
M. Rattanachaiyanont et al., Lack of correlation between oocyte-corona-cumulus complex morphology and nuclear maturity of oocytes collected in stimulated cycles for intracytoplasmic sperm injection, FERT STERIL, 71(5), 1999, pp. 937-940
Objective: To evaluate the usefulness of morphology grading of the oocyte-c
orona-cumulus complex (OCCC) as a marker of oocyte nuclear maturity, fertil
izability, embryo cleavage, and likelihood of pregnancy.
Design: Prospective cohort study.
Setting: Academic fertility center.
Patient(s): Eighty-three infertile couples undergoing IVF-ET/intracytoplasm
ic sperm injection treatment.
Intervention(s): All patients underwent a long stimulation protocol of GnRH
agonist therapy followed by hMG administration and transvaginal oocyte rec
overy.
Main Outcome Measure(s): All OCCCs, oocytes, and embryos were assessed. The
relation among OCCC morphology and the nuclear maturity of denuded oocytes
, the fertilization rate, and embryo development to the cleavage stage were
analyzed.
Result(s): Of 909 OCCCs collected from 92 cycles, 2.5%, 4.2%, 79.9%, and 13
.4% were prophase I, metaphase I, metaphase II, and degenerating, respectiv
ely. No statistically significant differences were found in the percentage
of intact metaphase II oocytes, the fertilization rate, or the cleavage rat
e among complexes With different morphologic grades. The morphologic grade
of the OCCCs of transferred embryos in the pregnant group was not different
from that in the nonpregnant group.
Conclusion(s): Most oocytes were iii metaphase II nl the time of retrieval
after ovarian stimulation. However, no relation was observed between the OC
CC morphologic grade and oocyte nuclear maturity, the fertilization rate, o
r embryo cleavage. These observations suggest that OCCC morphology grading
is a poor marker of oocyte quality. (C) 1999 by American Society for Reprod
uctive Medicine.