Treatment variables in relation to oocyte maturation: lessons from a clinical micromanipulation-assisted in vitro fertilization program.
OBJECTIVE
In an effort to understand the mechanism underlying the improved pregnancy rate observed in IVF cycles when gonadotropin-releasing hormone analogues (GnRH-a) are applied, we investigated a possible relationship between treatment variables and oocyte nuclear maturity.


METHODS
Nuclear maturity was retrospectively assessed in cumulus-free, denuded oocytes, obtained from women undergoing micromanipulation-assisted IVF treatment following controlled ovarian hyperstimulation with GnRH-a and menotropins.


METHODS
The setting was the infertility and IVF unit of a tertiary academic medical center.


METHODS
Two hundred twenty-one patients underwent 435 treatment cycles.


METHODS
This was the proportion of germinal vesicle-intact immature (GVII) oocytes.


RESULTS
One hundred fifty-four of the 3520 oocytes studied (4.4%) were in the GVII stage. These oocytes were found in 66 of the treatment cycles (15.2%) and in 54 of the patients (24.4%). Cycles in which GVII oocytes were detected did not differ from those in which all the aspirated oocytes were mature in the following respects: patient age, type and duration of infertility, controlled ovarian hyperstimulation protocol and time of ovum pickup. However, the GVII group was characterized by a significantly higher peak estradiol level, as well as a higher number of mature follicles visualized sonographically (diameter, > 14 mm) and oocytes retrieved.


CONCLUSIONS
Comparing the present findings with previously published data, it appears that the inclusion of GnRH-a in the stimulation regimen is associated with a lower proportion of immature oocytes. A higher occurrence of oocyte-nuclear immaturity is apparently associated with a significantly better ovarian response to stimulation. The high incidence of immature oocytes observed in patients with normospermic partners and low fertilization rates in previous cycles may suggest that the fertilization failure in some of these cases is due to oocyte, rather than sperm, dysfunction.
Avrech
O M
OM
Department of Obstetrics and Gynecology, Beilinson Medical Center, Petah-Tiqva, Israel.
Goldman
G A
GA
Rufas
O
O
Stein
A
A
Amit
S
S
Yoles
I
I
Pinkas
H
H
Fisch
B
B
D000328:Adult; D002064:Buserelin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D002452:Cell Count; D002467:Cell Nucleus / Q000648:ultrastructure; D006063:Chorionic Gonadotropin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D004958:Estradiol / Q000097:blood; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D007247:Infertility, Female / Q000097:blood / Q000188:drug therapy; D008596:Menotropins / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D008846:Micromanipulation; D009865:Oocytes / Q000648:ultrastructure*; D009866:Oogenesis / Q000187:drug effects; D010062:Ovulation Induction / Q000379:methods*; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies
D006063:Chorionic Gonadotropin; D004958:Estradiol; D008596:Menotropins; D002064:Buserelin