Aspects of multiple embryo transfer

Three hundred seventy-two patients underwent laparoscopy for in vitro fertilization and embryo transfer. Of these, 156 were treated with clomiphene citrate alone, 203 with clomiphene citrate and hMG, and 13 with hMG alone. Two-hundred seventy-two of these patients underwent embryo transfer, and 55 pregnancies resulted. Of these, 30 were ongoing, 14 biochemical, 6 ectopic, and 5 aborted. Where four embryos were transferred, the pregnancy rate was found to be significantly higher than when a lesser number were transferred. When the embryos transferred were analyzed, however, it was found that fewer than 10% of all transferred embryos implanted and it was largely a function of multiple embryo transfer per patient that led to success. When the type of hyperstimulation was compared, clomiphene citrate cycles were found to be less successful in that they produced fewer oocytes and embryos than did cycles in which hyperstimulation was achieved by supplementary hMG. It is conceded that this is an overall analysis and that individuals, especially those producing twins, had more than one good embryo transferred into a receptive uterus. The data suggest that unsuccessful cycles had somewhat poorer quality embryos, nonreceptive endometria, or a combination of these factors when compared with those of the successful embryo transfer cycles. The only predictive factor as to outcome relates to the multiplicity of embryos transferred. The fact that some IVF cycles produce multiple pregnancies indicates that a predictor of embryo health is urgently required. However, until such a reliable predictor is obtained, multiple embryo transfer remains a major advance in the success of IVF and ET.