asked Her Majesty's Government:
Further to the Written Answer by Lord Darzi of Denham on 19 March (WA 44), how the necessary organisational structure of a viable embryo has been determined on the basis of empirical studies of primate embryos; and whether they will place in the Library of the House a list of references to all peer-reviewed research papers which support the Human Fertilisation and Embryology Authority's decision on this matter.
The Human Fertilisation and Embryology Authority came to the conclusions on outgrowing embryos after taking account of the views of a range of scientific and clinical experts. Studies in the 1970s demonstrated that on a collagen surface the inner cell mass retains its 3D structure while on plastic it becomes completely flat. It was concluded that the retention of a 3D structure is key to its continuing to develop normally and form a recognisable embryo in vitro.
(Reference: Hsu YC (1971) Post-blastocyst differentiation in vitro. Nature. 14;231(5298):100-2).