Maturational asynchrony between oocyte cumulus-coronal morphology and nuclear maturity in gonadotropin-releasing hormone agonist stimulations.
OBJECTIVE
To determine oocyte meiotic maturity and asynchrony between cumulus-coronal morphology and nuclear maturity after gonadotropin-releasing hormone agonist (GnRH-a) and norethindrone-programmed stimulations.


METHODS
Oocyte meiotic maturity was evaluated at follicular aspiration in 4,961 oocytes after GnRH-a/follicle-stimulating hormone (FSH)/human menopausal gonadotropin stimulations (hMG) for in vitro fertilization patients and 299 oocytes after norethindrone-programmed clomiphene citrate (CC)/hMG in oocyte donors. Maturational asynchrony between the oocyte's cumulus-coronal morphology and nuclear maturity was evaluated in 2,336 oocytes.


METHODS
In vitro fertilization program at the University of Iowa Hospitals and Clinics; academic tertiary care center.


METHODS
After evaluating oocyte cumulus-coronal maturity, cumulus masses were spread to determine oocyte nuclear maturity.


RESULTS
Fourteen percent, 17%, 50%, 17%, and 2% of oocytes were prophase I, metaphase I, metaphase II, postmature metaphase II, and atretic, respectively. Asynchrony was noted in 28% of prophase I, 71% of metaphase I, 11% of metaphase II, 45% of postmature metaphase II, 32% of atretic, and 28% of all oocytes. Significant differences were not found between GnRH-a and norethindrone-programmed stimulations in asynchrony between cumulus-coronal morphology and nuclear maturity or percentage of prophase I, metaphase I, metaphase II, postmature metaphase II, or atretic oocytes. Sixty-seven percent of oocytes possessed a polar body at retrieval. The rate of fertilization was significantly higher for metaphase II oocytes than postmature metaphase II and metaphase I oocytes > prophase I oocytes. Parthenogenetic activation tended to be highest for postmature metaphase II oocytes. Embryo cleavage was significantly higher for postmature metaphase II, metaphase II, and metaphase I oocytes than for prophase I oocytes.


CONCLUSIONS
This is the first report of asynchrony between cumulus-coronal morphology and nuclear maturity at follicular aspiration in GnRH-a and norethindrone-programmed stimulations. Asynchrony was observed in 28% of oocytes. A higher percentage of oocytes possessed a polar body at egg retrieval with these stimulation regimens compared with rates reported previously for FSH, FSH/hMG, and CC/hMG stimulations.
Hammitt
D G
DG
Department of Obstetrics and Gynecology, University of Iowa Hospitals and Clinics, Iowa City 52242.
Syrop
C H
CH
Van Voorhis
B J
BJ
Walker
D L
DL
Miller
T M
TM
Barud
K M
KM
D002453:Cell Cycle; D002467:Cell Nucleus / Q000502:physiology*; D016922:Cellular Senescence; D002970:Cleavage Stage, Ovum; D005260:Female; D005306:Fertilization; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D009640:Norethindrone / Q000494:pharmacology; D009865:Oocytes / Q000502:physiology* / Q000648:ultrastructure; D013997:Time Factors; D017329:Triptorelin Pamoate / Q000031:analogs & derivatives*
D017329:Triptorelin Pamoate; D007987:Gonadotropin-Releasing Hormone; C019176:Tryptal; D009640:Norethindrone