Prenatal diagnosis in the human pre-implantation period. Meeting held at the Ciba Foundation on the 13th November 1986.

There is a clinical need for prenatal diagnosis before implantation for patients at high genetic risk who are unable to face the uncertainty of a pregnancy associated with conventional diagnostic methods, as well as for IVF patients who are at high risk for genetic or chromosomal anomalies. Research on human pre-embryos is required to establish: biopsy techniques during cleavage and at the blastocyst stage, in-vitro viability after biopsy, the culture potential of cells removed at these stages, cryopreservation of biopsied pre-embryos, and diagnostic procedures on biopsy material. The consensus view was that blastocyst biopsy is the most likely to succeed. The possibility should be considered of obtaining blastocysts by uterine lavage for diagnostic purposes in fertile women at high genetic risk. However it would be unethical to use uterine lavage to obtain blastocysts for research purposes. Rapid methods of typing the embryos the avoid the need for cryostorage, but there was a consensus (among those on the laboratory diagnostic side) that cryostorage would relieve some of the pressure of the ongoing diagnosis, and allow unhurried detailed analysis. All those present agreed that there is a need for further scientific research to establish pre-implantation diagnosis as a clinical reality. Close collaboration between workers in the fields represented will be necessary to achieve this goal.