Vitrification with DMSO protects embryo membrane integrity better than solutions without DMSO.

Vitrification has become common for cryopreservation of embryos. However, the most optimal protocol for vitrification is still to be found. Two vitrification protocols with similar osmolarities were compared: Protocol A, containing dimethyl sulphoxide (DMSO), propane-2-diol, and ethylene glycol, and Protocol B, containing propane-2-diol and ethylene glycol. Viability and the importance of specific incubation times for early embryo recovery, survival, and cleavage were studied. For assessment of cryodamage, embryos were labelled with Alexa Fluor 488-conjugated annexin V and propidium iodide. Vitrification studies on early mouse embryos were followed up with studies on human embryos. The two vitrification protocols did not differ in embryo survival rates and were equally efficient in both mouse and human embryo models. Morphological assessment of embryos directly after vitrification was not a useful tool for assessing survival in this study. Extended exposure of embryos with both vitrification protocols showed that the DMSO-containing vitrification solutions did not lead to cell membrane damage and death as quickly as the DMSO-free vitrification solutions. To assess embryo viability, the authors recommend that vitrification of early embryos should be combined with extended culture and assessment of normal blastocyst development before transferring to patients.

Mifepristone, but not levonorgestrel, inhibits human blastocyst attachment to an in vitro endometrial three-dimensional cell culture model.

BACKGROUND: The use of fertility regulating drugs is limited among various socio-ethnic groups due to limited knowledge about their mechanism of action. This study investigates the effect of levonorgestrel and mifepristone on attachment of human embryos to an in vitro endometrial construct. METHOD: Three-dimensional endometrial constructs were established by co-culturing early luteal phase human endometrial stromal and epithelial cells. Expression of endometrial receptivity markers in this construct were examined by immunohistochemistry. Effects of mifepristone and levonorgestrel on viability and attachment of human blastocysts were investigated. RESULTS: Endometrial constructs expressed the factors involved in endometrial receptivity: estrogen receptor, progesterone receptor, vascular endothelial growth factor, leukemia inhibitory factor, interleukin-1, COX-2, MUC-1 and integrin-alpha(V)beta(3). None of the 15 embryos cultured with mifepristone attached to the endometrial construct (P < 0.01), whereas 10/17 in control, and 6/14 in levonorgestrel, groups attached. The attachment was confirmed by the positive expression of cytokeratin 7 at the attachment site. CONCLUSION: Mifepristone inhibits blastocyst attachment. Levonorgestrel did not impair the attachment of human embryos to the in vitro endometrial construct. This model could be used to understand endometrial receptivity and embryo-endometrial dialog and to develop new fertility regulating substances.

Leukaemia inhibitory factor receptor and gp130 in the human Fallopian tube and endometrium before and after mifepristone treatment and in the human preimplantation embryo.

Leukaemia inhibitory factor (LIF) is a cytokine, which is associated with reproductive processes such as embryo development and implantation. The objectives of this study were to detect the presence of LIF receptor (LIFR) and glycoprotein 130 (gp 130) in the human Fallopian tube, endometrium and preimplantation embryo and to study the effect of mifepristone on the expression of LIFR and gp130 in the Fallopian tube. Twenty-two healthy fertile women received a single dose of 200 mg mifepristone or placebo immediately after ovulation (LH + 2). Biopsies were obtained from the Fallopian tubes during laparoscopic sterilization once between days LH + 4 and LH + 6 and from endometrium once between days LH + 6 and LH + 8. Preimplantation embryos were received from couples undergoing in vitro fertilization treatment. Immunohistochemistry was used to detect the presence of LIFR and gp130 in the Fallopian tube, endometrium and preimplantation embryo. Real-time PCR was used to study LIFR and gp130 expression in the Fallopian tube and endometrium. LIFR and gp130 were localized in the Fallopian tube, preimplantation embryo and endometrium. LIFR was more abundant in the Fallopian tube than in the endometrium. In the blastocyst, the staining of gp130 was mainly localized in the inner cell mass, whereas LIFR was expressed in all cells. The presence of LIFR and gp130 in the Fallopian tube and preimplantation embryo indicates a role for LIF in communication between the embryo and the Fallopian tube. Mifepristone did not affect the expression of LIFR and gp130 in the Fallopian tube, nor in the endometrium suggesting that progesterone might not be directly involved in the regulation of LIFR or gp130.