Implantation potential of each pre-embryo in XXXX obtained by in vitro fertilization seems to be different.

@entity1 @entity2099 @entity2085
Endometrial receptivity and pre-embryo quality are the main factors determining embryo implantation in in vitro fertilization. If one embryo implants normally and goes to term, the endometrium can be assumed to be normal. Eighty-one @entity1 (March 1981 to 1987) had transfers of multiple pre-embryos, resulting in @entity2099 with at least one reaching term. The number of gestational sacs at 8 to 12 weeks of pregnancy, at 20 weeks, and the number of term pregnancies were studied longitudinally. Twelve @entity1 (14.8%) had 2 pre-embryos transferred, 19 (23.5%) had 3, 21 (25.9%) had 4, 17 (21.0%) had 5, 9 (11.1%) had 6, and 3 (3.7%) had 7. At 20 weeks 18 @entity1 (22.2%) had a single viable fetus, 56 (69.1%) had twins, 6 (7.4%) had triplets, and 1 (1.2%) had quadruplets. A total of 325 pre-embryos were transferred; 178 gestational sacs were observed at 8 to 12 weeks, but only 153 showed fetal heartbeat. Total @entity2085 at 8 to 12 weeks was 53.0%; when the "index" embryo was excluded, it reached 61%. Regardless of the number of pre-embryos transferred, only 2.2 embryos on average were able to establish a normal pregnancy. (A)synchronism of the pre-embryos did not affect outcome. Results suggest that with normal endometrial receptivity, the implantation potential of each pre-embryo is different.
