Society for Maternal-Fetal Medicine Special Statement: Beyond the scalpel: in utero fetal gene therapy and curative medicine.

With the recent advances in gene editing with systems such as CRISPR-Cas9, precise genome editing in utero is on the horizon. Sickle cell disease is an excellent candidate for in utero fetal gene therapy, because the disease is monogenic, causes irreversible harm, and has life-limiting morbidity. Gene therapy has recently been proven to be effective in an adolescent patient. Several hurdles still impede the progress for fetal gene therapy in humans, including an incomplete understanding of the fetal immune system, unclear maternal immune responses to in utero gene therapy, risks of off-target effects from gene editing, gestational age constraints, and ethical questions surrounding fetal genetic intervention. However, none of these barriers appears insurmountable, and the journey to in utero gene therapy for sickle cell disease and other conditions should be well underway.