title: Comparative study of combined GIFT and IVF-ET with GIFT alone.
abstract: Twenty-eight couples with unexplained infertility, or with suboptimal spermatozoa were divided into two groups. One group underwent gamete intra-Fallopian transfer (GIFT), and the other had combined GIFT and in-vitro fertilization--embryo transfer (IVF-ET) (GET). There was a marked difference in pregnancy rates between the two groups, with the pregnancy rate surprisingly being less in the combined GET group; 10% for GET, as compared with 39% for GIFT alone. The results suggest that GIFT and IVF-ET are incompatible. Differences in the pregnancy rates may be explained by limitations in implantation, whereby the embryo-endometrium interaction that allows for implantation and continued embryonic development has a 'single event capacity', and once this interaction is initiated, the 'implantation window' is closed to other embryos that may arrive later in the uterus.
authors.affiliation: IVF Centre, Hong Kong Sanatorium and Hospital, Happy Valley.
authors.forename: M K
authors.initials: MK
authors.lastname: Leong
authors.forename: C K
authors.initials: CK
authors.lastname: Leung
authors.forename: V M
authors.initials: VM
authors.lastname: Marriott
authors.forename: C J
authors.initials: CJ
authors.lastname: Wong
authors.forename: Y M
authors.initials: YM
authors.lastname: Chan
authors.forename: H H
authors.initials: HH
authors.lastname: Chan
authors.forename: M J
authors.initials: MJ
authors.lastname: Tucker
mesh_terms: D000328:Adult; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D015181:Gamete Intrafallopian Transfer; D006801:Humans; D011247:Pregnancy