Comparative study of combined GIFT and IVF-ET with GIFT alone.
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.
Leong
M K
MK
IVF Centre, Hong Kong Sanatorium and Hospital, Happy Valley.
Leung
C K
CK
Marriott
V M
VM
Wong
C J
CJ
Chan
Y M
YM
Chan
H H
HH
Tucker
M J
MJ
D000328:Adult; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D015181:Gamete Intrafallopian Transfer; D006801:Humans; D011247:Pregnancy