Objective: To assess the influence of MII oocyte morphology on the
fertilization outcome and embryo development in ART cycles. Since, age
may affect the quality of oocyte, the role of women's age was also
evaluated following IVF or ICSI cycles. Materials and Methods:200 MII
oocytes from 30 IVF and ICSI cycles were evaluated. The morphology of
oocytes that were fertilized in IVF cycles (IVF+) was compared with
failed fertilization (IVF-). The oocytes were similarly categorized in
the ICSI procedure (ICSI+ and ICSI-). The criteria for morphological
evaluations were: a. normal oocytes showed clear cytoplasm with
homogenous fine granularity; b. granular oocytes, dark with granularity
either homogenous in whole cytoplasm or concentrated in the central
portion of the oocyte; c. cytoplasmic inclusions comprised vacuoles
presumed to be of endocytotic origin; d. dark zona pellucida (ZP), e.
fragmented polar body (PB) of different sizes; f. non-spherical shape
of oocyte; and g. wide previtelline space (PVS). Embryo transfer took
place 48 h after insemination/ injection. The statistical significance
of the data was analyzed using chi-square and Fisher's exact tests.
Results: A total of 67 and 78 oocytes were fertilized in IVF and ICSI
cycles, respectively. 46.3% and 35.9% of fertilized oocytes were shown
with normal morphology in IVF and ICSI cases, respectively. The rates
of grade A & B embryos were significantly higher in oocytes with
normal morphology (P<0.05). The mean number of embryos transferred
was similar in IVF and ICSI groups (3.3±0.4 versus 3.0±0.9).
In IVF+ and ICSI+, fragmented PBs were the highest rates of single
abnormality with 11.9% and 14.1%, respectively. Also, multiple
abnormalities were observed in 21.0% and 48.5% of oocytes in IVF+ and
IVF-, respectively (P<0.001). 15.4% and 31.8% of the oocytes from
ICSI+ and ICSI- were presented with more than one abnormality.
Refractile bodies were the highest type of single abnormality (18.2%)
in ICSI- group. Conclusions: In both IVF and ICSI, the highest rates of
fertilization and embryo formation took place in oocytes with normal
morphological features that were retrieved from young patients. The
most single morphological features involved in failed fertilization
were refractile body in ICSI and ooplasm granulation in IVF cases. The
data suggest that oocyte quality plays a major role in fertilization
process and embryo development in ART program