Oocytes with smooth endoplasmic reticulum clusters originate blastocysts with impaired implantation potential (original) (raw)
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The Effect of Morphological Parameters on IVF Outcomes in Single Blastocyst Transfer Cycles
Gazi Medical Journal
Aim: Our aim is to evaluate the effect of three morphological parameters (Blastocoel expansion, trophectoderm (TE) morphology grade, and inner cell mass (ICM) morphology grade) on clinical pregnancy in single blastocyst transfers. Methods: The study included 74 fresh day 5 single blastocyst transfers in a two-year period. There were 30 women with clinical pregnancy (Group 1). Women that failed to get pregnant after IVF/ICSI procedure were included in the non-pregnant group (n = 44) (Group 2). The blastocysts were graded according to Gardner and Schoolcraft. Age of the couple, body mass index, infertility duration, day 3 follicle stimulating hormone, luteinizing hormone, number of days of gonadotropin stimulation, total gonadotropin dose, estradiol level on the day of hCG administration, number of oocytes retrieved, number of metaphase II oocytes, number of 2PN, TE morphology, ICM morphology, blastocoel expansion were recorded. These outcomes were compared between the two groups. Statistical comparisons were carried out by Chi-square test and Student "t" test. Regardless of the statistical test, only a p value ≤ 0.05 was considered significant. Results: During the study period, 702 embryo transfers were performed; of these 74 (10.5%) were on Day 5. While number of oocytes retrieved, number of metaphase II oocytes and 2PN increased in pregnant group, estradiol level on the day of hCG administration, total gonadotropin dose, blastocoel expansion were similar in both groups. ICM and TE morphology were significantly associated with pregnancy (p<0.05). Conclusion: The clinical pregnancy rate seems to be affected by both ICM and TE morphology.
Role of Oocyte Morphological Abnormality Rates on the Embryo Development and Implantation
Gynecology Obstetrics & Reproductive Medicine
The aim of this study was to assess the impact of oocyte morphological abnormality rates on embryo development and implantation. STUDY DESIGN: Oocyte morphological abnormalities including oocyte size, elliptical shape, vacuole, plain polar body, fragmented polar body, large perivitellin space, perivitellin debris, central granulation, dense central granulation, inclusion body, thick zona pellucida, clusters of smooth endoplasmic reticulum, easy needle insertion and dark cytoplasm were determined for each oocyte. Rates of these oocyte morphological anomalies were determined for each case and the impact of rates on the cycle outcome was analyzed. RESULTS: Similar oocyte morphology abnormality rates were observed between cycles with and without successful embryo implantation. On the other hand, both fragmented polar body and vacuole rates were found to be significantly higher in cycles with Grade 2 embryo transfer. These rate differences were remained significant after adjustment for the age and basal FSH level. CONCLUSION: None of the oocyte morphological features was found to have significant impact on ART outcome.
Human Reproduction, 1998
In this study, we compared the fertilization rate and embryo quality after intracytoplasmic sperm injection (ICSI) as they relate to oocyte morphology. A total of 654 ICSI cycles yielding 5903 metaphase II oocytes were observed. The oocytes retrieved in these cycles were divided into (i) normal oocytes, (ii) oocytes with extracytoplasmic abnormalities (dark zona pellucida and large perivitelline space), (iii) oocytes with cytoplasmic abnormalities (dark cytoplasm, granular cytoplasm, and refractile body), (iv) oocytes with shape abnormalities, and (v) oocytes with more than one abnormality (double and triple abnormalities). Intracytoplasmic vacuoles and aggregates of smooth endoplasmic reticulum were not recorded separately. The fertilization rate and quality of morphologically graded embryos did not differ between the groups. There were 77 cycles where all transferred embryos were derived from abnormal oocytes, and 164 cycles where all embryos were derived from normal oocytes. These cycles were studied further. The two groups were comparable regarding mean female age, duration of infertility, duration of ovarian stimulation, number of ampoules of gonadotrophin injected, and number of oocytes retrieved. Two clinical pregnancy rates (44.4 versus 42.1%) and implantation rates per embryo (10.3 versus 13.2%) were similar. In conclusion, in couples undergoing ICSI, abnormal oocyte morphology is not associated with a decreased fertilization rate or unfavourable embryo quality. Furthermore, embryos derived from abnormal oocytes yield similar clinical pregnancy and implantation rates when transferred compared with embryos derived from normal oocytes.
Health, 2012
Purpose: Evaluate the effect of preincubation of oocytes prior to IVF or ICSI cycles with embryo transfer at blastocyst stage. Methods: Retrospective non randomized study based on secondary analysis of data. Setting: Laboratory of Assisted Reproduction at the Alcivar Hospital. Patients: One hundred-eighteen cycles of IVF and ICSI were analyzed in the present study. The evaluated groups were formed for those patients whose oocytes, after retrieval, were inseminated at 1-3 h (Group I) or 4-6 h (Group II). Results: There was no difference in fertilization rate (83.6% and 78.1%), Day 3 cleavage rate (95.1% and 97.1%), and blastocyst formation (31.1% and 39.1%) for groups I and II respectively. Clinical pregnancy rates (PR: 53.0% vs 22.9%) and implantation rates (IR: 38.1% vs 13.0%) were significantly higher in group II versus group I, respectively (P < 0.05). Conclusions: Preincubation of oocytes before insemination is a factor which raises the PR and IR after the blastocyst transfer.
Blastocyst quality affects the success of blastocyst-stage embryo transfer
Fertility and Sterility, 2000
To determine the relationship between blastocyst quality and the results of embryo transfer at the blastocyst stage. Retrospective case analysis. Tertiary care private hospital IVF center. A total of 350 blastocyst-stage embryo transfer cycles. In vitro culture to the blastocyst stage was undertaken in 350 ICSI cycles where four or more cleavage-stage embryos were available on day 3. Relationship between blastocyst quality and implantation and clinical and multiple pregnancy rates. Transfer of at least one grade 1 or grade 2 blastocyst or one hatching blastocyst was associated with very high implantation and pregnancy rates. However, transfer of grade 3 blastocysts yielded very low implantation and pregnancy rates. There appears to be a strong correlation between blastocyst quality and success of blastocyst transfer.
Fertility and Sterility, 1998
To determine the factors affecting blastocyst development and pregnancy after IVF and ET. Retrospective analysis of data arising from a clinical trial. Private in vitro fertilization clinic. Fifty-six patients aged < or = 40 years, undergoing IVF procedures for infertility, recruited specifically for blastocyst transfer. All zygotes were cultured to days 5 or 6 after insemination, and one to four of the most advanced blastocysts were transferred to the patient's uterus. Development of zygotes to blastocysts in vitro and pregnancy and implantation rates after ET. Fifty-one percent of all zygotes developed to blastocysts. Significant positive correlation between the number of blastocysts formed was observed with the number of oocytes, pronuclear zygotes, and eight-cell embryos formed. There was a negative correlation with male factor infertility. By day 5 or 6, 93% of the patients had at least one blastocysts, and the clinical pregnancy rate per transfer was 43% and the implantation per embryo transferred was 25%. No other clinical factor significantly affected the number of blastocysts formed, pregnancy rate, or implantation rate. The numbers of oocytes, zygotes, and normally developing embryos in culture significantly affects the production of blastocysts in vitro. Male infertility significantly reduces blastocyst production. The number and the quality of the blastocysts transferred significantly influences clinical pregnancy rate.
Fertility and Sterility, 2007
To evaluate the fertilization and developmental potential of immature oocytes obtained from controlled ovarian hyperstimulated cycles of patients undergoing intracytoplasmic sperm injection (ICSI).Retrospective study.Academic assisted reproductive technology program.Two hundred patients with at least one mature oocyte and one immature oocyte (study 1), and 44 patients with no mature oocytes (study 2) at time of oocyte denudation.Oocyte denudation was performed immediately after retrieval. Oocytes were cultured in vitro for 4–6 hours before ICSI and then categorized into four groups: group I, metaphase II (MII) oocytes at denudation; group II, in vitro matured MII oocytes; group III, metaphase I (MI) oocytes that did not progress to MII; and group 4, germinal-vesicle (GV) oocytes that converted to MI.Fertilization and embryo development were compared among groups in study 1. Pregnancy and implantation rates were evaluated in study 2.Although the fertilization rate in group III was significantly lower than in groups I and II, no significant difference was found between groups I and II. Day 3 embryos in group I had the highest mean number of blastomeres, proportions of good embryos, and blastocyst formation rate when compared with groups II and III. Two clinical pregnancies were achieved from 26 transfer cycles in study 2, resulting in pregnancy and implantation rates of 7.7% and 4% per transfer cycle, respectively.Although our results show that immature oocytes from stimulated cycles can be normally fertilized and used to increase the number of embryos available for transfer, the increase in number of embryos derived from immature oocytes cannot be efficiently translated into pregnancies and live births. The clinical significance of using immature oocytes in stimulated cycles needs further investigation.
Low blastocyst formation rates in day-2 fertilized oocytes
Journal of assisted reproduction and genetics, 1998
To examine the blastocyst formation rates of day-2 fertilized oocytes. A retrospective study of the outcomes/blastocyst formation of day-2 fertilized oocytes was undertaken. Fertilization rates of day-1 and -2 oocytes by intra-cytoplasmic sperm injection were similar. The development frequencies to four cells were similar. However, the blastulation rates were significantly lower from the day-2 fertilized eggs. The fertilization rates from day-2 conventional in vitro fertilization reinsemination were lower than the fertilization rates of day-1 oocytes. The blastulation rates from day-2 fertilized eggs were also lower than the rates from day-1 fertilized eggs in the in vitro fertilization group. Fertilization is not a good indicator to predict the viability of fertilized oocytes. Day-2 fertilized oocytes had significantly lower blastocyst formation rates than the rates from day-1 fertilized oocytes.