§ Mr. Campbellasked the Secretary of State for Social Services what is the source of medical evidence which states that 60 per cent. of human embryos do not implant in the womb, as given by the Minister of State on 15 February, Official Report, column 685.
§ Mr. Kenneth ClarkeTwo widely quoted scientific sources which refer to an implantation failure rate in the region of 60 per cent. are
Roberts, C. J., Lowe, C. R., Lancet 1975, vol. 1, pp 498–499.Lindley, M., Nature 1979, vol. 280, pp 635–636.I did describe the figure as a modest estimate.