I’m grateful to Dr Gill Lockwood for most of my medical and scientific information, and to David Hartshorn of Cellmark Diagnostics for background on DNA testing. For other matters, I’m indebted to Lee D’Courcy, Diana Cooper, Yvonne Twiby, Jai Penna, Paula Tyler, Brigid Baillie and the press office of the Human Fertility and Embryology Authority.