Faculty Bibliography

Objective: To establish prognostic relevance of parameters assessed in oocyte donation cycles.Design: Retrospective analysis.Setting: Large university-based donor oocyte program.Patient(s): All oocyte recipient cycles achieving embryo transfer from September 1995 to October 1998.Intervention(s): None.Main Outcome Measure(s): Pregnancy.Result(s): Recipient age and reproductive status, day 9 and 12 serum estradiol (E(2)) levels and a progesterone (P) level obtained 2 days after initiation of hormonal therapy did not correlate with pregnancy. Endometrial thickness, but not endometrial pattern, was useful in predicting pregnancy outcome. The clinical pregnancy and live-birth rate in cycles where the endometrial thickness was less than 8 mm was significantly lower when compared to cycles with an endometrial thickness >/=9 mm. Cycles where optimal quality embryos were transferred had the highest implantation (36%), clinical pregnancy (63%) and live birth (54%) rates and these rates were significantly higher than those of cycles where only poor quality embryos were available for transfer (10% implantation, 17% clinical pregnancy, and 8% live birth rates, respectively; P<.05).Conclusion(s): The most reliable predictive factors for pregnancy in oocyte donation cycles are the quality of the embryos transferred and the recipient's mid-cycle endometrial thickness. Recipient monitoring should minimally include ultrasound assessment of endometrial thickness

Oct-4, a decisive factor that maintains totipotency in murine embryonic and germ cells, is exclusively expressed in such cells. In mice, different levels of oct-4 expression in blastomeres predict development towards inner cell mass (ICM) (high oct-4) or trophectoderm (TE) (low oct-4). To address whether the mouse model also applies to human embryos, the cytoplasm of individual human blastomeres from normally and abnormally fertilized embryos was tested for Oct-4 expression by reverse transcription-polymerase chain reaction (RT-PCR). The nuclei of the same blastomeres were subjected to fluorescence in-situ hybridization (FISH) to determine ploidy. A significant difference in Oct-4 mRNA levels was revealed between blastomeres. The distribution of blastomeres with high Oct-4 levels varied according to the cleavage stage of the embryo: the more blastomeres, the lower the percentage with high Oct-4 levels. Aneuploid blastomeres did not exhibit lower Oct-4 mRNA levels than diploid ones. Thus, differential Oct-4 expression in individual human blastomeres appears to direct cells towards the ICM or TE lineages without regard to chromosomal status. Oct-4 might be used as a marker in preimplantation genetic diagnosis to identify embryogenic blastomeres