Eiko Otsu

Assessment of human oocyte developmental competence by cumulus cell morphology and circulating hormone profile

The predictive value of the morphology of the cumulus--oocyte complex (COC) has not yet been explored as a possible factor contributing to the success of human in-vitro maturation (IVM). In the present study, development-supporting competency of oocytes encircled in a large ( > or = 5) (grade A), moderate (3 approximately 4) (grade B) or small ( < or = 2) (grade C) number of cumulus cell layers was assessed, together with changes in hormonal profile following a truncated course of 150 IU pure FSH administration for 3 days prior to aspiration on laparoscopy indicated for endometriosis. FSH priming increased the number of COC aspirated without changing the proportion of the three morphological types of COC, which were then subjected to IVM in the presence of 200 mIU/ml FSH plus 1000 mIU/ml human chorionic gonadotrophin, followed by intracytoplasmic sperm injection. The highest development-supporting competence was observed not with oocytes in grade A COC harvested from natural cycles, but with oocytes in grade B COC from FSH-primed cycles. Hormonal profiles in patients bearing grade B COC were characterized by moderate response in oestradiol and progesterone production following FSH, with LH/FSH ratio being below 1.0. It is concluded that an optimal window of hormonal profile(s) may exist for follicle aspiration to obtain grade B COC in FSH-stimulated human IVM cycles.

The efficacy of the transfer of twice frozen-thawed embryos with the vitrification method

OBJECTIVE To confirm the clinical benefits of recryopreserved, twice-thawed embryo transfer (ET). DESIGN Retrospective study. SETTING Private fertility clinic. PATIENT(S) Forty-nine women whose embryos had been refrozen after a previous frozen-thawed ET. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Comparison of implantation and pregnancy rates of twice-cryopreserved, twice-thawed embryos versus once-cryopreserved, once-thawed embryos. RESULT(S) The pregnancy rate per ET cycle was 27.8% in the refrozen group and 25.9% in the control group (no statistically significant difference). The implantation rate was 25.0% in the refrozen group and 19.3% in the control group (no statistically significant difference). CONCLUSION(S) The refreezing of supernumerary embryos can prevent ovarian hyperstimulation syndrome in stimulated patients and in those who have experienced repeated failed pregnancies. If unexpected supernumerary embryos are available for recryopreservation after frozen-thawed ET, these embryos may be revitrified for a future transfer.

Developmentally retarded frozen blastocysts can be rescued by synchronizing culture prior to transfer

Asynchrony between embryo development and endometrial differentiation is the limiting step of successful pregnancy in assisted reproduction. The aim of this study was to investigate whether or not post-thaw synchronization culture of day 5-6 frozen embryos, prior to transfer, with endometrial differentiation resulted in pregnancy. A total of 142 cycles of 134 patients were transferred in three protocols. Blastocysts with cavities larger than half of the entire blastocyst volume were transferred without synchronizing culture on day 5 or 6 of progesterone commencement (P5/6) in hormone replacement treatment cycles (protocol 1). Blastocysts with cavitation below half of the entire blastocyst were cultured for 1 or 2 days after thawing prior to transfer on P5 or P6 (protocol 2). Morulae and very early stage blastocysts were thawed on the days corresponding to P5 and P6, and only the embryos that reached expanded or hatching blastocysts were transferred on P7 without synchronizing culture (protocol 3). Pregnancy rate in protocol 2 (32.0%) was comparable with that of protocol 1 (35.0%). It is concluded that developmentally retarded frozen embryos can be rescued with synchronizing culture prior to transfer by evading asynchrony.

Effects of cyclophosphamide administration on the in vitro fertilization of mice

To evaluate the oocyte fertilization ability and embryo growth after cyclophosphamide (CPA) treatment in mice.

Prediction of the in vitro developmental competence of early-cleavage-stage human embryos with time-lapse imaging and oxygen consumption rate measurement

To assess an embryos ability to develop into a good‐quality blastocyst during the early‐cleavage stage using time‐lapse imaging and the oxygen consumption rate.

The Relationship between the Level of Progesterone Secreted from Cumulus Cells and Oocyte Developmental Competence in In Vitro Matured Human Cumulus Oocyte Complexes

Abstract: Developmental competence of in vitro matured human oocytes is dependent on the morphology of the cumulus-oocyte complex (COC) just after collection from the follicle. We postulated that COCs categorized as having poor morphology (two or fewer less than two layers of cumulus cells) would not secrete a sufficient amount of matulation factors, resulting in low developmental competence of the matured oocytes. In the present study, the level of progesterone secreted from good morphology COCs with three or more layers of cumulus cells, 39.2 ± 12.8 ng/ml (n=31), was significantly higher than that secreted from poor morphology COCs (9.65 ± 1.34 ng/ml, n=22). The addition of 20 ng/ml progesterone to in vitro maturation culture of the poor morphology group significantly improved the fertilization ability of the oocytes. The rates of development to the morula and blastosyst stages were also increased by progesterone, however the differences were not significant. In conclusion, the secreted level of progesterone during in vitro maturation of human COCs was dependent on the number of cumulus cells attached to oocyte. When an oocyte is surrounded by two or fewer 2 layers of cumulus cells, the addition of progesterone to FSH- and hCG-containing medium appears to be a useful method for obtaining an oocyte with a high developmental competence.

Chromosome analysis of human refrozen embryos following fluorescence in situ hybridization

PurposeSeveral recent reports have discussed refrozen and thawed embryo transfer; however, the process may cause a degree of chromosomal damage and subtle genomic mutation. In view of this possibility, the purpose of this study was to investigate the incidence of aneuploidy in refrozen embryos.MethodsIn order to investigate the incidence of aneuploidy and mosaicism observed in chromosome 1, fluorescent in situ hybridization (FISH) was used on surviving embryos that first underwent one freeze-thaw cycle, then were allowed to develop to the blastocyst stage, and subsequently survived a second freeze-thaw cycle.ResultsOf 1,132 blastomeric nuclei analyzed from 15 refrozen embryos, disomy was found in 82.9%. In contrast, for the 11 blastocysts subjected to only one freeze-thaw cycle, disomy was noted in 78.4%. Of the 197 blastomeric nuclei analyzed in all arrested embryos, disomy was found in 51.8%.ConclusionsThe refreezing process did not increase aneuploidy. The good and fair morphology groups demonstrated a higher percentage of disomy than the poor morphology group regardless of whether they were frozen once or twice.

The Relationship between Genomic Imprinting and ART

ABSTRACT No abstract available.