Effects of three-area laser-assisted zona thinning in 8-cell human embryos on pregnancy outcomes in vitro fertilization.

OBJECTIVE: This study conducted a preliminary examination of the effects of three-area laser-assisted zona thinning (LAZT) during the cleavage stage of embryo development on the hatching process in human in vitro fertilization-embryo transfer (IVF-ET) with subjects of advanced female age or frozen-thawed (FT) embryos. METHODS: Eight-cell stage embryos were treated with LAZT in three areas of the zona pellucida at 120° intervals. The control group was embryos without LAZT. Of the 72 consecutive fresh cycles and the 28 FT embryo transfer cycles, the patients in 55 fresh cycles and 17 FT cycles declined LAZT, and those cycles were defined as the control group. RESULTS: In the fresh cycles, the pregnancy rates were similar in the LAZT and control groups. However, in the FT cycles, the pregnancy rate was significantly higher in the LAZT group than in the control group (45.5% in the LAZT group vs. 23.5% in the control group, p<0.05). CONCLUSION: These results show that multi-area LAZT resulted in significantly improved pregnancy outcomes in human 8-cell embryos compared to controls.

Quantitative Assessment of Endometrial Volume and Uterine Vascularity and Pregnancy Outcome in Frozen-Thawed Embryo Transfer Cycles.

OBJECTIVE: To investigate the usefulness of the endometrial volume and vascular indices in the endometrial region as an effective predictor for pregnancy outcome in frozen-thawed embryo transfer (FET). STUDY DESIGN: We evaluated 131 embryo transfer cycles in 73 infertile women. After controlled ovarian stimulation all embryos were cultured to blastocyst stage, and the blastocysts with good quality were vitrified for elective FET. On the day of FET, endometrial thickness, endometrial volume, pulsatility index (PI), and resistance index of uterine artery and endometrial-subendometrial vessels (ESVs) with zonal discrimination were evaluated by transvaginal ultrasonography in each patient. These variables were compared between pregnant and nonpregnant cycles. RESULTS: The endometrial volume was significantly higher in the pregnant group (2.32 ± 0.86, 1.96 ± 0.62 mL, p = 0.007). Also, PI of ESVs was significantly higher in the pregnant cycle (2.58 ± 1.32 and 2.05 ± 1.08, p = 0.016). The other variables were not different between the 2 groups. CONCLUSION: This study suggested that endometrial volume and the vascular indices measured in endometrial region are useful predictors of pregnancy outcome.

Vitrification solution without sucrose for cryopreservation in mouse blastocysts.

OBJECTIVE: This study was designed to investigate the survival rate of vitrified mouse blastocysts depending on the presence or absence of sucrose in vitrification solution. METHODS: Mouse two-cell embryos were collected and cultured to blastocysts. Two vitrification solutions were prepared. The control solution was composed of 25% glycerol, 25% ethylene glycol, and 0.5 M sucrose (G25E250.5S) containing 2.5 mL glycerol, 2.5 mL ethylene glycol, 2 mL SSS, and 0.855 g sucrose in 5 mL PB1. The experimental solution was composed of 25% glycerol and 25% ethylene glycol (G25E25) and contained 2.5 mL glycerol and 2.5 mL ethylene glycol in 5 mL PB1. Artificial shrinkage was conducted by aspirating the blastocoelic fluid using an ICSI pipette. To examine the effect of sucrose in the vitrification solution on the survival rate of mouse blastocysts, the shrunken-equilibrated blastocysts were rehydrated or vitrified after being exposed to one of the two vitrification solutions. After exposure and the vitrification-thawing process, the re-expansion rate and hatching rate were evaluated after 6 hours of in vitro culture. RESULTS: The re-expansion rate of mouse blastocysts exposed to vitrification solution with and without sucrose were not different in the experimental solution (without sucrose) (98%) and the control solution (with sucrose) (92%) (p>0.05). The hatching rate was higher in the experimental solution (95%) than in the control solution (88%), but did not differ across two treatments (p>0.05). The re-expansion rate of mouse blastocysts vitrified in the control solution was 92% and 94%, respectively (p>0.05), and the hatching rate was higher in the experimental solution (90%) than in the control solution (74%) (p<0.05). CONCLUSION: Sucrose need not be added in vitrification solution for freezing of artificially shrunken mouse blastocysts.

Measurement of endometrial and uterine vascularity by transvaginal ultrasonography in predicting pregnancy outcome during frozen-thawed embryo transfer cycles.

AIM: An appropriate endometrial condition and vascular supply are usually considered essential for implantation of an embryo. This study was performed to assess the role of endometrial and uterine vascularity status measurement in predicting pregnancy outcome during frozen-thawed embryo transfer cycles. MATERIAL AND METHODS: A total of 70 infertile women were recruited with controlled ovarian stimulation followed by oocyte retrieval. After in vitro fertilization or intracytoplasmic sperm injection, embryos were cultured to blastocysts and blastocysts with good quality were selected for cryopreservation. After endometrial preparation, vitrified blastocysts were thawed and assisted hatching by zona dissection was performed. On the day of embryo transfer, endometrial thickness (EMT), resistance index (RI) and pulsatility index (PI) of sub-endometrial artery (SEA) and uterine artery (UA) were obtained by transvaginal sonography. The women were divided into the pregnant and non-pregnant groups, and these variables were compared between the two groups. RESULTS: Patients' general demographic characteristics were not statistically different between the pregnant and non-pregnant groups. The overall implantation rate, clinical pregnancy rate, and ongoing pregnancy rate were 31.1%, 41.4% and 28.6%, respectively. Twenty-nine patients who conceived had average EMT, RI of SEA, PI of SEA, RI of UA, and PI of UA values of 9.15 mm, 0.91, 2.42, 0.95, and 3.37, respectively. Forty-one patients who did not conceive had average EMT, RI of SEA, PI of SEA, RI of UA, and PI of UA values of 9.31 mm, 1.01, 2.56, 0.94, and 3.00, respectively. In the two groups, none of the variables was statistically different (P > 0.05). CONCLUSIONS: EMT and blood flow index of endometrium and uterus measured by transvaginal sonography are not an effective predictor of pregnancy outcome in frozen-thawed embryo transfer cycles.