Chromosome analysis in embryos from young patients with previous parity.

This study included 173 young couples of proven fertility who had previously undergone preimplantation genetic screening for chromosomes X and Y for family balancing. Several months later, when the outcome of the pregnancies was already known, the blastomeres from the corresponding embryos transferred were reanalysed by fluorescence in-situ hybridization (FISH) for chromosomes 13, 16, 18, 21, 22 with the aim of investigating correlation with embryo viability and the level of FISH sensitivity (embryos confirmed to be euploid). According to the results, informative in 152 couples, the proportion of euploid embryos was significantly lower in 53 nonpregnant women when compared with 99 women with term pregnancy (49% versus 75% respectively, P < 0.001). In addition, in 21 nonpregnant patients, all embryos transferred were found to be chromosomally abnormal. The level of FISH sensitivity was calculated in the group of term pregnancies where the number of euploid embryos was expected to exceed or match with the number of babies born. The resulting false-negative rate was 4.0% per patient and 1.9% per embryo. These findings confirmed the limited prediction power of embryo morphology on implantation but also the relevance of chromosomal abnormalities in causing embryo demise.

Sex selection and preimplantation genetic diagnosis at The Farah Hospital.

The issue of sex selection by using preimplantation genetic diagnosis (PGD) for non-medical reasons has been the subject of heated debate. Although the ethical arguments regarding this subject are complex, we would like to extend and express some views based on practical experience, with a special focus on individual needs in developing countries, taking into consideration: social, cultural, religious, financial and scientific aspects.

Dichloroacetic acid accelerates initial development of 2-cell murine embryos in vitro.

Preimplantation embryos up to the 8-cell stage of development use lactate and pyruvate but not glucose or Krebs cycle intermediates to support growth, development, and cleavage. The dominant effect of dichloroacetic acid (DCA) is the irreversible stimulation of pyruvate dehydrogenase (PDH) activity, thus accelerating the oxidative metabolism of pyruvate and lactate. To test the hypothesis that early induction of oxidative metabolism in 2-cell murine embryos accelerates preimplantation embryo cleavage rates, female B6C3F1 mice at 6 to 8 weeks of age were superovulated with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) and mated. All 2-cell stage embryos were randomly assigned to culture media with or without 130 micrograms/mL DCA. The developmental stage of all embryos was then noted every 24 hours for a total of 72 hours. Chi-square analysis and the method of average rank sum were used to compare the distribution of embryos at each observation point. At 24 hours, DCA-exposed embryos had achieved an advanced stage of growth and development relative to controls (average rank sum, P = .026; chi-square distribution, P = .047). Subsequently, at 48 and 72 hours, neither the average rank sum nor the chi-square distribution was different. Our data suggest that DCA accelerates early growth and development of murine embryos before implantation, possibly through the early induction of oxidative metabolism.