title: The use of intra-endometrial embryo transfer for increasing the pregnancy rate.
abstract: It has been demonstrated previously that pregnancy can be achieved by the direct insertion of embryos into the endometrial stroma (intra-endometrial embryo transfer) of mice. In this study we evaluated whether intra-endometrial transfer resulted in a higher pregnancy rate than conventional embryo transfer. Mouse blastocysts (ICR strain), recovered on day 4 of pregnancy, were transferred into pseudopregnant day 2, day 3 and day 4 mice of the same strain; 1-, 2- and 8-cell embryos were also transferred into pseudopregnant day 4 mice. In intra-endometrial embryo transfer, a 27 gauge injection needle was inserted near the utero-tubal junction into the endometrial stroma and then removed; one blastocyst was transferred into each uterine horn with a glass micropipette. Conventional transfers were performed simultaneously as controls. The pregnancy rates and embryonic viability rates were evaluated 9 days after embryo transfer. Furthermore, the rates of live birth for intra-endometrial and conventional embryo transfers were compared when blastocysts were transferred into pseudopregnant day 4 uteri by both methods. In the transfer to pseudopregnant day 2 recipients, the pregnancy and embryonic viability rates were significantly higher (P < 0.01) in intra-endometrial [23.4 (11/47) versus 15.9% (15/94)] than in conventional embryo transfer [4.3 (2/46) versus 2.2% (2/92)]. In the transfer to pseudopregnant day 3 recipients, both rates were also higher (P < 0.01) in intra-endometrial [90.9 (40/44) versus 87.5% (77/88)] than in conventional transfer [67.4 (31/46) versus 64.1% (59/92)].(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Gynaecology and Obstetrics, Kyoto University Faculty of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakayama
authors.forename: Y
authors.initials: Y
authors.lastname: Goto
authors.forename: H
authors.initials: H
authors.lastname: Kanzaki
authors.forename: K
authors.initials: K
authors.lastname: Takabatake
authors.forename: T
authors.initials: T
authors.lastname: Himeno
authors.forename: Y
authors.initials: Y
authors.lastname: Noda
authors.forename: T
authors.initials: T
authors.lastname: Mori
mesh_terms: D000818:Animals; D001723:Birth Rate; D004624:Embryo Transfer / Q000379:methods*; D004717:Endometrium; D005260:Female; D005328:Fetal Viability; D007267:Injections; D051379:Mice; D008813:Mice, Inbred ICR; D011247:Pregnancy; D018873:Pregnancy Rate