Scientific hazards of human reproductive 'cloning'.

The scientific and clinical professional societies and associations covering the remit of Human Fertility are unanimously opposed to human reproductive 'cloning'. This article describes the main scientific objections to human reproductive 'cloning'. Data collected from numerous studies in a range of animal species indicate a high incidence of fetal defects, a stillbirth rate typically of more than 90% and a lack of adequate information on postnatal development. These concerns are exacerbated by misconceptions about the current ability to screen preimplantation embryos for 'cloning-induced' defects. Scientists and clinicians are sometimes treated with mistrust in the eyes of the public and media over such issues, perhaps because scientific information is not as well communicated as it might be. The duty of reproductive specialists is to convey the limits of their knowledge on this issue to the public and policymakers.