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The rate of development and time of transfer play different roles in influencing the viability of human blastocysts 总被引:7,自引:6,他引:1
Shoukir Y; Chardonnens D; Campana A; Bischof P; Sakkas D 《Human reproduction (Oxford, England)》1998,13(3):676-681
Improved embryo culture protocols now render more feasible the possibility
of obtaining human blastocysts after in-vitro fertilization. In this study
we present: (i) results of blastocyst development from supernumerary
embryos after co-culture on green monkey kidney epithelial cells and (ii)
pregnancy rates after transfer of frozen blastocysts. In addition, we have
examined the influence of the day of blastocyst freezing and the day of
transfer after the luteinizing hormone (LH) peak on pregnancy and
implantation rates. Of 423 supernumerary embryos, 200 developed to the
blastocyst stage (47.3%). By days 5 and 6, 67% of the blastocysts had
reached the blastocyst stage, and were frozen, compared to 28.5% by day 7.
When we compared the cases where only blastocysts frozen on days 5 and 6
were transferred compared to those frozen and transferred on or after day 7
the pregnancy rates were 7/18 (38.9%) and 1/16 (6.2%) respectively. In
contrast, when we examined the influence of the day of transfer we found
that pregnancies were established from day 5 up to day 9 post LH peak.
Based on these results, we suggest that every attempt should be made to
increase the development rate of supernumerary embryos to the blastocyst
stage, as it appears that the quality of blastocysts transferred, as shown
in this study by rate of development, plays a more crucial role than the
timing of transfer.
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2.
Blastocyst development from supernumerary embryos after intracytoplasmic sperm injection: a paternal influence? 总被引:28,自引:24,他引:4
Shoukir Y; Chardonnens D; Campana A; Sakkas D 《Human reproduction (Oxford, England)》1998,13(6):1632-1637
The success of intracytoplasmic sperm injection (ICSI) warrants further
study on the role of paternal factors in early human embryogenesis. To
investigate whether poor sperm parameters can influence embryo development,
we examined the development of ICSI-fertilized embryos to the blastocyst
stage. We present results of blastocyst development from supernumerary ICSI
embryos after co-culture on monkey kidney epithelial cells. In addition, we
compare the development of supernumerary embryos to the blastocyst stage
after ICSI and in-vitro fertilization (IVF). Of 168 supernumerary ICSI
embryos, 45 (26.8%) developed to blastocysts. Sperm concentration and
morphology did not influence blastocyst development. In contrast,
blastocysts arose from spermatozoa that had a significantly higher (P =
0.015) forward progressive motility compared with spermatozoa from those
patients who failed to produce blastocysts (42.7% versus 28.2%,
respectively). Overall the rate of embryo development to the blastocyst
stage after ICSI was lower (26.8%) than that after IVF (47.3%). When the
rate of blastocyst development was calculated for patients with three or
more supernumerary embryos, it remained significantly higher for the IVF
patients than for the ICSI patients (45.6% versus 30.0%). There was no
significant difference in the mean cell number and quality of the
supernumerary embryos between the IVF and ICSI patients. This study
confirms previous reports that have postulated that abnormal spermatozoa
may manifest a negative paternal effect on preimplantation embryo
development.
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3.
Sakkas D Urner F Bizzaro D Manicardi G Bianchi PG Shoukir Y Campana A 《Human reproduction (Oxford, England)》1998,13(Z4):11-19
In the first part of this report we investigate whether chromatin anomalies in human spermatozoa can influence fertilization after intracytoplasmic sperm injection (ICSI). We have examined the sperm chromatin packaging quality using the chromomycin A3 (CMA3) fluorochrome and the presence of DNA damage in spermatozoa using in-situ nick translation. When comparing the spermatozoa of patients undergoing in-vitro fertilization (IVF) and ICSI distinct differences are evident in that ICSI males have a higher CMA3 fluorescence, indicating spermatozoa with loosely packed chromatin, and more spermatozoa containing endogenous DNA nicks. When examining the unfertilized oocytes of ICSI patients we found that men who had a high percentage of anomalies in their chromatin, i.e. > 30% CMA3 fluorescence and > 10% nicks, had more than double the number of unfertilized oocytes containing spermatozoa that had remained condensed. The observation that failed fertilized oocytes, injected with spermatozoa from patients with a higher percentage of sperm nuclear anomalies, contain more condensed spermatozoa indicates that a selection process against these spermatozoa may be in place at the time of fertilization. In the second part of the study we show that spare ICSI embryos have significantly lower rates of development to the blastocyst stage compared with those developed after routine IVF. These results show that a greater understanding of the molecular basis of male infertility is therefore needed to broaden our knowledge on the effect that abnormal spermatozoa have on fertilization and embryo development. 相似文献
4.
Early cleavage of human embryos to the two-cell stage after intracytoplasmic sperm injection as an indicator of embryo viability 总被引:6,自引:11,他引:6
Sakkas D; Shoukir Y; Chardonnens D; Bianchi PG; Campana A 《Human reproduction (Oxford, England)》1998,13(1):182-187
In-vitro fertilization (IVF) embryos are selected for transfer on the basis
of morphology and rate of development. However, when a number of embryos
have similar characteristics, the selection of the best embryos is left to
chance. Recently, we proposed a simple, novel method to overcome this
problem, based on pre-selection of embryos cleaving early to the two-cell
stage. In this study we have adopted the same method to choose embryos
fertilized after intracytoplasmic sperm injection (ICSI). Fertilized
embryos that had cleaved to the two-cell stage by 27 h post-injection were
designated as 'early cleavage' embryos, while those that had not yet
reached the two-cell stage were designated as 'no early cleavage'. In all
cases, the early cleavage embryos were transferred when available. Early
cleavage was observed in 54 (61.4%) of the 88 cycles assessed. There were
significantly (P = 0.04) more clinical pregnancies in the early cleavage
group, 14/54 (25.9%), compared with the no early cleavage group 2/34
(3.2%). No differences between the groups were found when comparing key
parameters (age, stimulation protocol and semen characteristics) of the
couples. Using the ICSI technique, we have shown that early cleavage to the
two-cell stage is not influenced by the timing of fertilization, and is
more likely due to intrinsic factors within the oocyte or embryo that
promote embryo cleavage after fertilization.
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5.
Early cleavage of in-vitro fertilized human embryos to the 2-cell stage: a novel indicator of embryo quality and viability 总被引:31,自引:18,他引:13
A number of non-invasive methods have been proposed to evaluate embryo
viability in human in-vitro fertilization programmes. In addition to
biochemical analyses, a common method for the selection of embryos prior to
transfer involves assessment of embryo quality and morphology. We propose a
new method to evaluate embryo viability based on the timing of the first
cell division. Fertilized embryos that had cleaved to the 2-cell stage 25 h
post-insemination were designated as 'early cleavage' embryos while the
others that had not yet reached the 2-cell stage were designated as 'no
early cleavage'. In all cases the early cleavage embryos were transferred
when available. Early cleavage was observed in 27 (18.9%) of the 143 cycles
assessed. There were significantly (chi2 = 4.0; P = 0.04) more clinical
pregnancies in the early cleavage group, 9/27 (33.3%), compared with the no
early cleavage group, 17/116 (14.7%). No difference was found when
comparing key parameters (age, stimulation protocol and semen
characteristics) of couples belonging to both groups, pointing to an
intrinsic property or factor(s) within the early cleaving embryos. We
propose 'early cleavage' as a simple and effective non-invasive method for
selection and evaluation of embryos prior to transfer.
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