No abstract

A total of 816 women who underwent 1332 cycles of ovarian stimulation for in-vitro fertilization and embryo transfer (IVF/ET) had sonographic assessments of the endometrium within 2 days of oocyte retrieval. Endometrial linings were classified on the basis of thickness and echogenicity, using a grading system described previously. Grades I and IIB ('poor') were associated with a 6% viable pregnancy rate (advanced beyond 12 weeks' gestation) compared with a 29% rate for Grade IIA ('optimal'). In a subset of 112 women with poor endometrial linings during natural cycles, eight out of 21 women (38%) under 40 years of age developed optimal linings following ovarian stimulation with menotrophins, while 19 out of 91 women (21%) aged 41-45 years converted to optimal linings. Twenty-two out of 47 women (44%) who failed to develop optimal endometrial linings following ovarian stimulation converted to Grade IIA during subsequent cycles of exogenous oestrogen replacement. The financial, emotional, and physical burden associated with IVF/ET demands that patients with poor endometrial linings following ovarian stimulation with menotrophins be counselled with regard to either cancelling their cycles of treatment, or having their embryos cryopreserved for transfer to the uterus during a subsequent hormonal replacement cycle.

No abstract

Some major drawbacks of a bicarbonate-buffered culture medium include the requirement of an elaborate incubator system able to maintain a 5% CO2 environment and the inability of the culture medium to maintain a physiological pH range (pH 7.3-7.4) in room air (0.03% CO2). This work resulted in the development of IVF culture media, BB (modified T6) and Hams-HEPES, which use HEPES-buffered systems not requiring the specialized CO2 environment to maintain a physiological pH range in room air. These media generate above-average cleavage rates in in vitro fertilized, superovulated B6CBAF1 mice ova. The effect of heparin and HEPES on cleavage was studied and neither had a significant effect at the concentrations used. Cleavage rates of nonfertilized ova (parthenogenic division) were 9 to 13%. There was no significant difference in parthenogenesis between any of the culture media and it appears to be a function of the strain of mice and the timing between human chorionic gonadotropin (hCG) injection and ovum collection. These results emphasize the need to account for parthenogenesis when determining cleavage rates of in vitro fertilized mouse ova. Also, the results suggest that because of individual mouse differences in cleavage rates, it is important to use an adequate number of mice per group to determine an accurate, average cleavage rate.

Our findings confirm that damage induced by sustained islet compaction results in poor graft outcome in mice. These findings raise concerns relating to potential damage to human islets prior to clinical transplantation, and this will be explored in further studies.