The term in-utero gene therapy (also known as fetal gene therapy or prenatal gene therapy) is used to describe the concept of applying somatic gene therapies to the embryo even before birth in order to prevent genetic diseases. One concept originates from the physician and human geneticist Charles Coutelle. According to him, the intrauterine gene transfer has certain advantages over postnatal treatment. It is for instance assumed that the embryo or fetus absorbs the recombinant DNA better than a born child, which might enable a life-long production of the therapeutic gene product. It is also assumed that this treatment method causes significantly lower immune reactions against the vector and gene product. 

On the other hand, such a procedure carries certain risks, such as infection, premature labor and miscarriage. It is also not possible to completely rule out undesirable germline effects. Risks are therefore not only conceivable for the mother and the fetus itself, but also for possible future generations. 

Furthermore, establishing such a treatment method requires research on human embryos. There is controversy about the conditions under which it would be justified to use embryos as objects of corresponding experiments. This therapeutic approach has so far only been researched in animal models. In view of the risks and uncertainties, prenatal gene therapy currently does not represent a treatment alternative.