To avoid multiple pregnancies, it is important to select a single high quality embryo for transfer. Observation of meiotic spindles in oocytes is one way of evaluating embryo developmental competence. The spindle is non-invasively visualized by polarized light microscopy. It is possible to perform ICSI more safely and with optimal timing during meiosis by visualizing the meiotic spindle just before ICSI. In some human studies, it has been reported that oocytes with a spindle show significantly higher fertilization, blastocyst formation and pregnancy rates. Recently, it has been reported that morphological spindle normality is related to the live birth rate. In mice, the areas of the spindles in aged oocytes (23 h after hCG injection) are larger than those in young oocytes (15 h after hCG injection), and the blastocyst formation rate of aged oocytes is lower than that of young oocytes. Addition of MG132, a ubiquitin-mediated proteasome proteolysis inhibitor, to the medium prevents the spindle from becoming large and increases the blastocyst developmental rate. Therefore, it is thought that the spindle configuration and chromosome arrangement reflect the physiological stage or quality of an oocyte. Spindle imaging provides a useful index for comprehensively assessing embryo quality.

Varicocele repair and testicular sperm extraction (TESE) are most commonly performed for infertile males. Generally, TESE is performed to retrieve spermatozoa in azoospermic patients, and varicocelectomy is used to restore the possibility of spontaneous pregnancy by recovering sperm parameters. Most recently, indications for these treatments have been extended with the spread of intracytoplasmic sperm injection (ICSI). To decrease the DNA damage of spermatozoa, TESE for severe oligozoospermia and varicocelectomy for azoospermia or severe oligozoospermia are considered treatment options. However, there is insufficient data with which to draw conclusions about the efficacy of these treatments; the outcomes appear to show improvement to some extent. To achieve a successful ICSI outcome for the improvement of male factor infertilities, these treatments should be offered to selected patients. During selection, patients, especially those with severe oligozoospermia who frequently have a genetic disorder should undergo genetic analysis before treatment.

Since the establishment of intracytoplasmic sperm injection (ICSI) in 1992, sperms have been observed, evaluated, and selected under an inverted microscope at 400 × magnification for ICSI. Intracytoplasmic morphologically selected sperm injection (IMSI) is a technique in which sperms are selected for micro insemination by more precisely observing their morphology, at increased magnification under an inverted microscope used for micro-insemination and enhancing the image resolution. Approximately 20 years have passed since IMSI was developed, and its efficacy has only been confirmed in cases with a high rate of sperm aneuploidy, a high rate of sperm DNA fragmentation, and repeated ICSI failures. It is well-known that the quality of sperms has a profound effect on the quality of embryos which may eventually become children. Therefore, when micro-insemination is performed, sperms should be selected by not only paying attention to their motility, but also by closely observing their morphology. Those engaged in fertility treatment should always keep in mind that sperm selection itself has a significant influence on patients' lives.

Fertilization failure occurs in 1–5% of ICSI cases. An abnormality of the oocyte activating ability of spermatozoa is one of a major causes of fertilization failure. For such cases, artificial oocyte activation (AOA) is expected as a method of treating for fertilization failure after ICSI. There are various methods of AOA combined with ICSI. We have adopted treatment with calcium ionophore, A23187, which is a commonly used method, and here, we report on the present status of the methods of oocyte activation combined with ICSI that we use. Although AOA with electrical technique or chemicals stimulation is clinically performed, the safety of this has not yet been proven, and the safer effective methods of AOA are desired.

The morphology, sizes and abnormality rates of spermatozoa in the night monkey were revealed in the present paper. Motile spermatozoa of three males, 7, 8 and 12–13 years old, were squeezed from the ducts of the cauda epididymis after cutting the ducts in cryopreservation media. The morphology of the spermatozoa and abnormalities in them were observed, and the sizes of the spermatozoa were measured in smear samples. The spermatozoa of the night monkey had heads with rounded and thick shapes. Measurement of the spermatozoa revealed that the average widths and lengths of the heads, average lengths of the middle pieces, and average total lengths from the head to tail tip were 4.7 ± 0.8, µm and 2.8 ± 0.4 µm, 6.6 ± 2.2, µm and 55.1 ± 6.2 µm, respectively (average ± SD). The total rates of abnormal spermatozoa were different among the 7-, 8- and 12–13- year-old night monkeys, 41.8%, 24.0% and 36.5%, respectively. Freezing of semen was also attempted using the procedure contained in a commercial kit for the mouse. Although the motility of the spermatozoa from the night monkeys was poor in fresh samples, the motility of their spermatozoa frozen-thawed with the commercial kit was similar to that before freezing.

This study examined the effect of hyperglycemic culture conditions on the development of oocytes derived from early antral follicles (EAFs). Oocyte—granulosa cell complexes (OGCs) derived from EAFs were cultured for 12 days in medium containing 5.56 mM or 11 mM glucose, and the rate of antrum formation and glucose consumption by the OGCs, and the characteristics of the oocytes grown in vitro were studied. The results were compared with those obtained from in vivo grown oocytes derived from antral follicles (AFs; 3–5 mm in diameter). In addition, the effect of a high glucose concentration in the maturation medium on the quality of oocytes derived from AFs was examined. The high glucose condition increased the glucose consumption of the OGCs but did not affect antrum formation, oocyte diameter, chromatin configuration, levels of histone 4 K12 acetylation, nuclear maturation, and the developmental ability of oocytes grown in vitro. In contrast, high glucose-maturation medium increased the amount of reactive oxygen species and adversely affected the developmental ability of the oocytes. In conclusion, the results of this study suggest that culture under hyperglycemic conditions is detrimental to oocyte maturation but not for oocyte growth from the EAF stage to the AF stage.

The absence of reliable markers to identify viable embryos for transfer at the early cleavage stage may contribute to the generally low implantation rates and high incidence of multiple births associated with IVF treatment. In the present study, we examined the relationships among the timing of the first cleavage, incidence of blastocyst formation in vitro, and pregnancy outcomes. All embryos (n=1,748) were examined for early cleavage at 25 h after insemination. Three groups were defined based on the persistence of two pronuclei (PN group), pronuclei breakdown (BD group), and early cleaved zygotes (EC group). Each embryo (n=1,120) was cultured until day 6 of development, and assessed for blastocyst formation. The rate of blastocysts showing good morphology was significantly higher in the EC group (44.7%) than in the BD (26.9%) or PN (13.9%) groups. The cryothawed good morphology blastocysts were transferred in 209 cycles. The clinical pregnancy rate was the highest and the abortion rate was the lowest in the EC group. These results indicate that early cleavage is indicative of increased developmental potential in human embryos and may be useful as an additional criterion when selecting embryos for transfer.

Background. Lysophosphatidic acid (LPA) receptor 3 expressed in the uterus plays a critical role in uterine receptivity for the embryo. We investigated whether human embryos produce LPA by analysis of a human embryo-conditioned medium (HECM). Methods. LPAs in HECM were extracted by the Bligh-Dyer method. Extracted LPAs were converted to trimethylsilyl (TMS) derivatives. Gas chromatography (GC)/ selected ion monitoring (SIM) and GC / mass spectrometry (MS) were used to analyze LPAs derivatized with TMS. Monitoring and quantitative analysis of LPAs were performed using GC/SIM with [M-15] ion derived from LPAs. Identification of LPAs was confirmed by GC/MS. Results. LPA-C16:0, 16:1, 18:0, 18:1 and 18:2 were detected in HECM. The concentration of LPAs was calculated by comparing each detected peak area with a corresponding standard LPA. Conclusion. This study is the first study in which five molecular species of LPAs produced by human embryos were detected in HECM and their quantities analyzed.