Fertilization and early embryology: Granulosa cells improve human embryo development in vitro

A total of 17 couples with repetitive implantation failure aftertransfer of fresh or frozen—thawed embryos had half oftheir zygotes cultured in standard conditions and frozen atday 2 after insemination, and the other half cocultured withautologous granulosa cells and transferred at the morula orblastocyst stage at day 5 or 6 after oocyte retrieval. At theend of the culture period, supernatants of cocultures were recoveredfor steroid assays. Monolayers were stained for granulosa cellgrowth and morphological assessment. We observed that granulosacells improve embryo development in vitro since 32 out of 60(53%) reached the morula stage and 18 (30%) the blastocyst stage,leading to a total of 83% embryos available for transfer (comparedwith 3% without coculture). The ongoing pregnancy rate of thesepatients who were selected because they had at least three previousimplantation failures, is only 5.9%, however, which is similarto the control group without coculture (6.3%). To conclude,granulosa cells improve embryo development but not the pregnancyrate after transfer of cocultured embryos in patients with multipleprevious implantation failures.