Influence of early ICSI-derived embryo sHLA-G expression on pregnancy and implantation rates: a prospective study

BACKGROUND: We have previously reported the retrospective observation that when at least one embryo, transferred on day 3, expressed sHLA-G above the geometric mean (sHLA-G+) 46 h post-ICSI, there was a marked improvement in both pregnancy (PR) and implantation (IR) rates. METHODS: The media surrounding individual embryos derived from ICSI performed on oocytes from 482 women <= 43 years of age were tested for sHLA-G expression by specific ELISA. RESULTS: We report here prospective results showing improved IVF results following the transfer of 'good quality' embryos (7-9 cells with < 20% fragmentation) by preferentially including at least one sHLA-G+ embryos. PR and IR for women <= 38 years were 63% and 32% when one transferred embryo was sHLA-G+, and 69% and 36% when at least two embryos were sHLA-G+. When none of the embryos transferred was sHLA-G+, PR and IR were 25% and 13%, respectively. Comparable PR and IR for women 39-43 years were 29% and 11% when none of the transferred embryos were sHLA-G+; 38% and 15% when at least one sHLA-G+ embryo was transferred; and 61% and 26% when at least two 2 sHLA-G+ embryos were transferred. The data were stratified by patient age. CONCLUSIONS: PR and IR increased with the addition of each sHLA-G+ embryo, regardless of age. While there are significant barriers to routine embryo sHLA-G testing, we believe that if implemented, this would provide a mechanism for optimizing IVF PR while minimizing the risk of multiple pregnancies.