Effect of laser-assisted multi-point zona thinning on development and hatching of cleavage embryos in mice / 대한생식의학회지

OBJECTIVE: This study aimed to examine the effect of laser-assisted zona thinning (LAZT) at one or four-points on the blastocyst formation and hatching process in mice with respect to female age. METHODS: Eight-cell or morula embryos collected from superovulated C57BL female mice with different ages (6-11 and 28-31 weeks) were treated with LAZT at one-point (LAZT1) or four-points (LAZT4). The zona pellucida was thinned to more than 70% of its initial thickness by making two holes of 15-20 microm. RESULTS: In the young mice, LAZT resulted in a significant increase in early hatching and hatching rates compared to the control group (p<0.05). However, in the old mice, LAZT significantly increased blastocyst formation as well as early hatching and hatching compared to the controls (p<0.05). These effects were more remarkable in LAZT4 than in LAZT1 and in aged mice than in young ones. CONCLUSION: These results show that multi-point LAZT leads to a significant improvement of blastocyst formation and hatching in mice compared to controls.

Expression of SDF-1alpha and leptin, and their effect on expression of angiogenic factors in mouse ovaries / 대한생식의학회지

OBJECTIVE: Ovarian angiogenesis plays an important role in folliculogenesis. However, little is known about the expression of angiogenic factors during follicular development according to female age. Stromal cell derived factor-1alpha (SDF-1alpha) plays a role in granulosa cell survival and embryo quality as an angiogenic chemokine. Leptin is also involved in folliculogenesis and angiogenesis. This study examined expression of SDF-1alpha and leptin, and their effects on the expression of angiogenic factors in the ovary during follicular development according to female age. METHODS: Ovaries were collected from C57BL mice of two age groups (6-9 weeks and 24-26 weeks) at 6, 12, 24, and 48 hours after 5 IU pregnant mare's serum gonadotropin (PMSG) injection. The expression of ovarian SDF-1alpha and leptin mRNA was evaluated by RT-PCR. In the organ culture experiment, the ovaries were cultured in transwell permeable supports with Waymouth's medium treated with various doses of SDF-1alpha (50-200 ng/mL) or leptin (0.01-1 microg/mL) for 7 days. Then, mRNA expression of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS), and visfatin were examined in the cultured ovaries. RESULTS: Expression of SDF-1alpha and leptin in the ovary was significantly lower in the aged mouse group compared to the young mouse group (p<0.05). Expression of these two factors increased with follicular development after PMSG administration. SDF-1alpha treatment stimulated visfatin expression in a dose-dependent manner, while leptin treatment significantly increased eNOS expression. CONCLUSION: These results suggest that decrease of ovarian SDF-1alpha and leptin expression may be associated with aging-related reduction of ovarian function. SDF-1alpha and leptin may play a role in follicular development by regulating the expression of angiogenic factors in mouse ovaries.

Effect of serum E2 levels on the pregnancy outcome of IVF-ET / 대한산부인과학회지

OBJECTIVE: To evaluate the effects of serum E2 levels on the day of hCG administration on the pregnancy outcome of IVF-ET after controlled ovarian hyperstimulation (COH). METHODS: Data of 455 cycles of fresh IVF-ET with COH were retrospectively investigated. Serum E2 levels on the day of hCG administration were categorized into 5 groups; A ( or =4,000 pg/mL). RESULTS: Mean E2 levels on the day of hCG administration were 3,745.3 pg/mL and mean number of retrieved oocytes were 10.1. Of 455 cycles, 148 (32.5%) cycles were clinically pregnant. Implantation rate was 12.2% and delivery rate was 18.7%. The number of obtained oocytes increased with increasing levels of serum E2. Pregnancy rate gradually increased as E2 levels increased up to the group D, but began to fall in the group E. In younger women ( or =38 yrs), pregnancy rate and delivery rate were significantly higher in the group C than other groups. CONCLUSIONS: This result shows that serum E2 levels have a concentration-dependent effect on the pregnancy outcome and there is an optimal range of E2 levels to achieve for a successful pregnancy. Excessive E2 levels seem more deleterious to the pregnancy outcome in older women aged > or =38 years.

Short Coasting of One or Two Days by Withholding Both Gonadotropins and GnRH Agonist Prevents Ovarian Hyperstimulation Syndrome without Compromising the Outcome / 대한불임학회지

OBJECTIVE: To evaluate the effect of short coasting, by withdrawing both gonadotropins and GnRH agonist (GnRHa), on the prevention in severe ovarian hyperstimulation syndrome (OHSS) without compromising pregnancy outcome. METHOD: Thirty-seven women who had been coasted during COH for IVF were coasted when > or =20 follicles > 15 mm with serum E2 level of 4,000 pg/ml were detected. Coasting was initiated for one or two days depending on the status of follicle on ultrasound and serum E2 level. Both gonadotropin and GnRHa were withheld for coasting. Retrospective study was carried and changes of serum E2 levels, number of oocytes retrieved, fertilization rate, pregnancy rate were compared and analyzed. RESULTS: The mean serum E2 level fell from 6,993 pg/ml on the onset of coasting to 3,396 pg/ml on the day of hCG administration. The mean number of oocytes retrieved and fertilization rate were 15.7 and 70.0%, respectively. Fifteen patients were pregnant (40.6%) and implantation rate was 15.2%. Twenty-six (70.3%) patients were coasted for one day and 11 (29.7%) were coasted for two days. The mean decrease rate of serum E2 level was 43% in one day coasting group and 15% (1st day) and 81% (2nd day) in two day coasting group. The pregnancy outcome was similar between the two groups. After coasting, no severe or moderate OHSS occurred in any patients and mild OHSS occurred in 3 (8.1%) patients. CONCLUSIONS: Coasting for one or two days can be used successfully in the prevention of OHSS without compromising IVF cycle outcome.

Improvement of Pregnancy Rate by the Selection of Early Cleavage Embryos to 2-cell Stage in Human IVF / 대한불임학회지

OBJECTIVE: Evaluation of embryos using early cleavage to 2-cell stage has been proposed, but a critical time-point for selecting embryos is unclear. The aim of the present study is to provide a guideline including critical time-point in the selection of early cleaving embryo for the reduction of multiple pregnancies as well as the increase of pregnancy rate in human IVF. METHODS: This prospective study was performed in 116 cycles from 85 patients who underwent conventional IVF or ICSI at the infertility clinic of Good Moonhwa Hospital from January 2002 to December 2003. Early cleavage (EC) of embryos to 2-cell stage was assessed at 25 h and 27 h postinsemination/microinjection. Embryos that had early cleaved at each time point were designated as EC-1 and EC-2, respectively, while others were designated as non-early cleavage (NEC). RESULTS: At least one early cleavage embryo was observed in 54 (46.6%) for the EC-1 and 84 (72.4%) for the EC-2 of the 116 cycles assessed. Clinical pregnancy rates (PR) were significantly higher in the EC-1 group (66.7%) compared to the EC-2 group (53.6%) or the NEC group (31.2%) (p<0.05). Significant improvement of the pregnancy rate was found when at least two or more embryos were early cleaved at 25 h postinsemination or when the proportion of early cleavage embryo at 25 h postinsemination was higher than 20% (p<0.05). CONCLUSIONS: The critical time-point for the selection of early cleavage embryos with high implantation potential is more effective in 25 h postinsemination/microinjection compared to 27 h. The proportion as well as number of early cleavage embryos is also an important factor for the prediction of pregnancy outcome and the chance of multiple pregnancies. These results demonstrated that the evaluation of early cleavage embryos to 2-cell stage is an easy, simple, and objective method for the selection of good quality embryos suitable for embryo transfer.

Dose-Dependent Inhibitory Effect of Nitric Oxide on Embryo Development / 대한불임학회지

No abstract available.