Mouse blastocyst vitrification compared with the conventional slow-freezing method.

To compare mouse blastocyst survival after cryopreservation with vitrification and the slow-freezing method, one-hundred and forty-eight in vitro mouse blastocysts were randomly frozen by the two methods: vitrification and conventional slow-freezing. After being thawed, the blastocysts were assessed for survival and hatching rate. The survival rates of blastocysts cryopreserved by vitrification and slow-freezing were 68.33 and 65.52 per cent (p = 0.89), whereas hatching rates were 51.22 and 44.74 per cent, respectively (p = 0.64). Therefore, vitrification of blastocyst-stage-embryos may be a useful, economic method for freezing the excess blastocysts in some centers where blastocysts are routinely transferred.

Correlation between human follicular diameter and oocyte recovery, metaphase II oocytes and fertilization rate in intracytoplasmic sperm injection programs.

This prospective study was undertaken to establish the correlation between the follicular diameter, oocyte recovery, metaphase II (MII) oocyte, and fertilization rate in intracytoplasmic sperm injection (ICSI) programs. Thirty one patients undergoing 31 ICSI cycles from August 1998 to January 1999 at King Chulalongkorn Memorial Hospital were studied. The patients were stimulated with either short or long GnRHa portocol. During transvaginal aspiration of follicles, follicular diameters were measured. The maturation stage of oocytes and fertilization rate were evaluated. Four hundred and seventy eight follicles were measured and classified into 3 groups, group A (<10 mm), group B (10-14 mm) and group C (>14 mm). The oocyte recovery rate and MII oocytes were different between groups A, B, and C but the fertilization rate was not different. In conclusion, the follicular diameter correlated with oocyte recovery and oocyte maturation but not with the fertilization rate in ICSI programs. The quality of embryos was lower in oocytes from small follicles.

Effects of contaminated endometriotic contents on quality of oocytes.

The mechanism of infertility associated with endometriosis is poorly understood. There is evidence supporting that women with ovarian endometriosis have a lower pregnancy rate than women with peritoneal lesions only. This study aimed to evaluate the effects of endometriotic contents contamination while retrieving oocytes on oocytes' quality. Thirty-eight infertile patients with endometriotic cysts from January 1993 to June 2000 were enrolled in this study. There were no statistically significant differences among the quality of oocytes and embryos from the contaminated, non-contaminated, and control group. However, the fertilization rate and pregnancy rate were impaired by the contamination of endometriotic contents. We conclude that ovarian endometriosis should be treated before starting in vitro fertilization program in order to increase the pregnancy outcome.

Bilateral tubal pregnancy following in vitro fertilization and embryo transfer.

We have presented a case of bilateral tubal pregnancy following in vitro fertilization and embryo transfer. The most likely cause, in our opinion, is 'spray effect' which was discussed. The diagnosis of ectopic pregnancy must always be kept in mind in IVF&ET program, due to its high incidence of occurrence compared to natural conception. Although the incidence of bilateral tubal pregnancy is not high, one should identify the opposite adnexa when tubal pregnancy is diagnosed in an IVF&ET patient. Early diagnosis is essential for prevention of significant maternal morbidity and mortality.