On the scientific and ethical issues of fetal somatic gene therapy

Fetal somatic gene therapy is often seen as an ethically particularly controversial field of gene therapy. This review outlines the hypothesis and scientific background of in utero gene therapy and addresses some of the frequently raised questions and concerns in relation to this still experimental, potentially preventive gene therapy approach. We discuss here the choice of vectors, of animal models and routes of administration to the fetus. We address the relation of fetal gene therapy to abortion, to post-implantation selection and postnatal gene therapy and the concerns of inadvertent germ-line modification. Our views on the specific risks of prenatal gene therapy and on the particular prerequisites that have to be met before human application can be considered are presented.