Maternal-fetal interventions continue to be a groundbreaking and rapidly expanding area. In this article, we examine whether it is ethically permissible to conduct investigation into the expansion of inclusion criteria for existing maternal-fetal interventions to include pregnant patients with human immunodeficiency virus (HIV) and hepatitis B or C infection with low or undetectable viral loads. We addressed this ethical question by appealing to ethical principle of respect for the autonomy of the pregnant patient; the patient status of the fetus; the balance of overall benefits and risks of the procedure(s) to pregnant, fetal, and neonatal patients; and to the ethical principle of justice. The ethical framework we have provided supports the conclusion that research on maternal-fetal interventions with pregnant women with HIV and hepatitis B and C infection with low or undetectable viral loads is ethically permissible. To accumulate sufficient numbers, such research should be multicenter.