Retrospective study of single vitrified-warmed blastocyst transfer cycles according to the presence of morphokinetic variables.

This study retrospectively assessed whether time-lapse data relating to developmental timing and morphology were associated with clinical outcomes, with the eventual goal of using morphokinetic variables to select embryos prospectively for cryopreservation. In this study, we examined the clinical outcomes of single vitrified-warmed blastocyst transfer cycles that were cultured in a time-lapse incubation system. The morphokinetic variables included uneven pronuclei, an uneven blastomere, multinucleation, and direct, rapid, and irregular division. A total of 164 single vitrified-warmed blastocyst transfer cycles were analyzed (102 cycles of regularly developed blastocysts and 62 cycles of blastocysts with morphokinetic variables). No significant differences in the age of females or the standard blastocyst morphology were found between these two groups. The regularly developed blastocysts showed significantly higher implantation and clinical pregnancy rates than the blastocysts exhibiting morphokinetic variables (30.4% vs. 9.7% and 37.3% vs. 14.5%, respectively; p<0.01). The blastocysts that exhibited morphokinetic variables showed different mean development times compared with the regularly developed blastocysts. Although morphokinetic variables are known to have fatal impacts on embryonic development, a considerable number of embryos developed to the blastocyst stage. Morphokinetic variables had negative effects on the implantation and clinical pregnancy rates in vitrified-warmed blastocyst transfer cycles. These findings suggest that blastocysts cultured in a time-lapse incubation system should be considered for selective cryopreservation according to morphokinetic variables.

Optimal ICSI timing after the first polar body extrusion in in vitro matured human oocytes.

BACKGROUND: This study was conducted to investigate the fertilization and embryo development of human oocytes injected at different time intervals after extrusion of the first polar body (PB) following in vitro maturation (IVM) in IVM cycles. Also, we evaluated whether spindle imaging could serve as a tool to determine the optimal ICSI time. METHODS: Oocytes were collected from 43 women with polycystic ovary syndrome. Metaphase I (MI) oocytes after in vitro culture for 24 h from germinal vesicle stage were subjected to ICSI according to time after first PB extrusion. The intervals were: within 1 h (n=38); 1-2 h (n=30); 2-4 h (n=26);4-6 (n=28) and 6-8 h (n=40). In some MI oocytes, viable spindle location was evaluated using Polscope microscopy at different time intervals after first PB extrusion. RESULTS: Fertilization rate of the MI oocytes injected within 1 h after first PB extrusion was low (15.8; 6/38) (P<0.01 versus all other times). In contrast, the fertilization rate was 80, 92.3, 82.1 and 85% for oocytes injected 1-2, 2-4, 4-6 and 6-8 h after first PB extrusion, respectively. Development of good-quality embryos was not significantly different among all the groups. Interestingly, all the oocytes injected within 1 h after first PB extrusion were in Telophase I. CONCLUSIONS: Human oocytes matured in vitro needed at least 1 h after first PB extrusion to complete nuclear maturation. Use of a live spindle imaging system can help to decide the timing of ICSI for oocytes matured in vitro.

Visualization of the metaphase II meiotic spindle in living human oocytes using the Polscope enables the prediction of embryonic developmental competence after ICSI.

BACKGROUND: Meiotic spindles in living human oocytes can be visualized by the Polscope. This study investigated the relationship between the presence/location of the spindle in metaphase II (MII) oocytes and developmental competence of embryos in vitro. METHODS: The spindles in 626 MII oocytes were examined by the Polscope and divided into six groups (A-F) based on the presence or absence of the spindles and the angle between the spindle and the first polar body. After ICSI, the fertilization and embryo development were evaluated. RESULTS: Meiotic spindles were imaged in 523 oocytes (83.5%), while 103 (16.5%) did not have a visible spindle (group F). The majority of oocytes (68.8%) had the spindle directly beneath or adjacent to the first polar body (groups A and B: 48.2 and 20.6%). Oocytes in group C (11.2%) had the spindle located between 60 and 120 degrees angle away from the first polar body, those in group D (2.4%) had the spindle located between 120 and 180 degrees angle and those in group E (1.1%) had the spindle located at 180 degrees angle to the first polar body. The fertilization and embryonic development were similar in the oocytes with spindles regardless of spindle position. However, the rate of high quality embryos was significantly higher in the oocytes (64.2%) with visible spindles than in the oocytes (35.9%) without spindle and multipronuclear proportion showed a slight tendency to increase in oocytes without spindles. (10.7 versus 5.9%, P = 0.12; NS). CONCLUSIONS: the presence of a bi-refringent meiotic spindle in human oocytes by using the Polscope can predict a higher embryonic developmental competence. However, the relative position of the spindle within the oocyte doesn't appear to influence the developmental potential of embryos.

Successful birth after transfer of blastocysts derived from oocytes of unstimulated woman with regular menstrual cycle after IVM approach.

PURPOSE: To report a delivery after transfer of blastocysts derived from eggs collected following in vivo HCG priming in a patient with regular menstrual cycles undergoing in vitro maturation (IVM) program. METHODS: A woman had regular menstrual cycle and had experience of ovarian hyperstimulation syndrome (OHSS) during a previous conventional IVF-ET cycle. The patient was primed with 10,000 IU HCG 36 h before egg retrieval. After oocyte collection, the maturity of oocytes was evaluated and immature oocytes were cultured in IVM medium. The matured oocytes were fertilized with husband sperm, and normal fertilized eggs were cultured to blastocysts stage until embryo transfer in uteri. RESULTS: Three MII-stage and 13 GV-stage oocytes were collected from the patient. Three mature oocytes were fertilized by conventional IVF. All three fertilized oocytes were developed to blastocysts. Immature oocytes were matured in vitro and insemination was carried out by ICSI. Out of eight fertilized zygotes, two developed to blastocyst stage. Transfer of three expanded blastocysts on Day 6 resulted in pregnancy in the patient and one healthy baby was born. CONCLUSIONS: This report provides an approach to treat infertile women with regular menstrual cycle and high risk of OHSS.