Pregnancy rate, multiple pregnancy rate, and embryo quality: Clues for single blastocyst transfer from double blastocyst transfer in an unselected population.

Objective: Minimizing multiple pregnancy is a priority in assisted reproduction. As implantation rates are critical to success and reduce multiple pregnancy, we investigated whether blastocyst grade determined implantation rate following double blastocyst transfer in unselected cases. Materials and Methods: We studied 69 three-cleavage stage embryo transfers and 64 two-blastocyst transfers. Two blastocysts, or one when two blastocysts were not available, were transfered after evaluating the grade of blastocysts. The difference in pregnancy and implantation rates to patient age, the number of retrieved oocytes and grade of blastocysts were analyzed. Results: Blastocyst and grade 3AA rates per fertilized egg were 50.3% and 26.0%, respectively. Following two-blastocyst transfer, pregnancy rate per transfer, implantation rate per embryo, and multiple pregnancy rate per pregnancy were 39.1%, 26.5%, and 24.0%, respectively. Two-blastocyst transfer achieved implantation more often than three-cleavage-stage embryo transfer, but did not reduce multiple pregnancy. Pregnancy, implantation, and multiple pregnancy rates did not reflect maternal age. Higher pregnancy and implantation rates per transfer were attained for with six or more oocytes retrieved or transfer of two-blastocyst graded 3AA or higher especially when two or more blastocysts graded 3AA or higher are available, but the latter showed a high multiple pregnancy rate (38.5%). Conclusions: Single embryo transfer could be carried out when two or more blastocysts of grade 3AA or higher have been developed. (Reprod Med Biol 2005; 4: 153-160).

Prediction of outcomes of assisted reproduction treatment using the calcium ionophore-induced acrosome reaction.

BACKGROUND: Sperm concentration and motility are poor predictors of the outcome of intrauterine insemination (IUI), hysteroscopic intratubal insemination (HIT), or complete fertilization failure (CFF) in conventional IVF. We investigated whether the calcium ionophore-induced acrosome reaction (AR) constitutes an additional indicator of CFF and pregnancy that is independent of these semen parameters. METHODS: Infertile couples with no female factor (n=388) and women with tubal obstruction (n=32) were studied: IVF (n=133), ICSI (n=72), HIT (n=245) and IUI (n=61). The percentage of acrosome-reacted sperm in relation to viable sperm was calculated. Receiver operating characteristic curve and multiple logistic regression analyses were used to determine threshold values and the best predictor for CFF and pregnancy. RESULTS: Threshold values of AR for predicting CFF in IVF and pregnancy in IVF and HIT + IUI were 21, 26 and 22% respectively. These values were independent of the conventional semen analysis parameters. CFF was lower (2 versus 20%; P<0.01) and the pregnancy rate was higher (46 versus 24% P<0.05) for those with AR >21% in IVF. CFF and pregnancy rate in ICSI did not differ according to AR. Pregnancy rate was higher for those with an AR >22% for HIT + IUI (23 versus 11% P<0.01). CONCLUSIONS: Ionophore-induced AR appears to be a useful indicator in addition to routine semen analysis for selection of patients for treatment with appropriate assisted reproduction procedure.

Mechanisms regulating the expression of indoleamine 2,3-dioxygenase during decidualization of human endometrium.

BACKGROUND: Expression of the tryptophan catabolizing enzyme, indoleamine 2,3-dioxygenase, in the mouse placenta has been shown to be critical in preventing immunological rejection of the fetal allograft. To clarify the physiological importance of indoleamine 2,3-dioxygenase in human pregnancy, we have studied how the expression of this enzyme changes during decidualization of human endometrium at both the cell and tissue level. METHODS AND RESULTS: The level of indoleamine 2,3-dioxygenase mRNA expression (determined by RT-PCR) was higher in decidual than in endometrial tissue. Uterine decidual tissue in ectopic pregnancy similarly showed increased mRNA expression. Immunohistochemistry demonstrated that indoleamine 2,3-dioxygenase protein immunoreactivity was found in glandular epithelium and in stromal cells. The intensity of this immunoreactivity was increased in decidualized tissue. In a cell culture model, the level of indoleamine 2,3-dioxygenase mRNA was suppressed specifically by progesterone-induced decidualization of isolated endometrial stromal cells. Indoleamine 2,3-dioxygenase protein abundance (determined by Western blot) was also decreased by progesterone-induced decidualization. However interferon-gamma, a potent stimulator of indoleamine 2,3-dioxygenase gene expression, increased the level of indoleamine 2,3-dioxygenase mRNA and protein in both non-decidualized and in decidualized cells. Indoleamine 2,3-dioxygenase activity (determined by measuring the concentration of tryptophan and its indoleamine 2,3-dioxygenase catabolite, kynurenine) was also decreased by progesterone-induced decidualization but enhanced following interferon-gamma treatment. Expression of other interferon-gamma inducible genes (STAT1 and tryptophanyl-tRNA synthetase) showed the same pattern as that of indoleamine 2,3-dioxygenase in tissue samples, but was not changed by decidualization in the cell culture model. CONCLUSIONS: These data suggest that despite suppression by progesterone, indoleamine 2,3-dioxygenase expression in endometrial stromal cells may increase during decidualization due to stimulation by interferon-gamma secreted by infiltrating leukocytes.

Indoleamine 2,3-dioxygenase: distribution and function in the developing human placenta.

Studies in mice have suggested that the placenta is protected from immune rejection by maternal T cells by means of localised indoleamine 2,3-dioxygenase dependent depletion of tryptophan. To determine whether such mechanisms might operate in the human placenta, we have studied the physiological importance of human placental indoleamine 2,3-dioxygenase immunohistochemically and functionally. Indoleamine 2,3-dioxygenase is detectable immunohistochemically from day 6 human blastocysts and thereafter throughout pregnancy in syncytiotrophoblasts, extravillous cytotrophoblasts and macrophages in the villous stroma and in the fetal membranes. Interferon-gamma added to villous explants markedly stimulates indoleamine 2,3-dioxygenase protein expression in macrophages. Indoleamine 2,3-dioxygenase-mediated tryptophan degradation in the first trimester villous and decidual tissue explants is stimulated by interferon-gamma and inhibited by 1-methyl-tryptophan (an inhibitor of indoleamine 2,3-dioxygenase). Peripheral blood mononuclear cell proliferation is controlled by indoleamine 2,3-dioxygenase-mediated tryptophan degradation. These results suggest the cellular basis of a mechanism present at the human maternal-fetal interface involved in regulating the maternal immune response to conceptus.

Significance of human neutrophil antigen-2a (NB1) expression and neutrophil number in pregnancy.

BACKGROUND: Expression of human neutrophil antigen-2a (HNA-2a) is greater in women than in men. The size of the HNA-2a-positive neutrophil population increases with pregnancy. STUDY DESIGN AND METHODS: T he relationship between HNA-2a expression on neutrophils and monocytes, and their relative numbers, was investigated. HNA-2a expression shown as the size of the HNA-2a-positive cell population and the fluorescence intensity on the cells was analyzed using flow cytometry. This investigation was done among 165 pregnant women during pregnancy and postpartum. RESULTS: In normal pregnancy, numbers of neutrophils and monocytes changed in relation to HNA-2a expression. HNA-2a was also expressed intensively on monocytes from some pregnant women in the first and second trimesters. HNA-2a expression and the number of cells markedly decreased postpartum. In threatened premature labor, the number of neutrophils decreased earlier than in normal pregnancy. CONCLUSION: HNA-2a expression may increase soon after fertilization. In this study, the results indicate that the change in the number of neutrophils and monocytes is related to HNA-2a expression.