The Ethics of Clinical Research on Diseases of the Fetus and Newborn: Balancing Benefit-Risk, Autonomy, and Maternal-Fetal Interests.

Pregnant persons historically have been excluded from clinical trials. Recently, there has been a shift from exclusion toward inclusion of pregnant persons in research while acknowledging the complexity of reproductive ethics and the intertwined interests of the pregnant person and fetus. Our objective was to use a principle-based approach to review the ethics of clinical research concerning pregnancy-related disorders that predominantly affect fetal well-being.Ethical principles are applied to the design of interventional trials in two rare conditions of pregnancy, hemolytic disease of the fetus and newborn (HDFN) and fetal and neonatal alloimmune thrombocytopenia (FNAIT).Severe HDFN and FNAIT are fetal and neonatal diseases caused by maternal alloantibodies with potential outcomes including maternal and neonatal morbidity, preterm delivery, and fetal or neonatal death. Early-onset severe HDFN was the initial indication for a phase 2 open-label study of nipocalimab in pregnancy, given poor outcomes after prior severe HDFN pregnancy(s). After establishing proof of concept, a phase 3 randomized placebo-controlled study was initiated based on the ethical principles of equipoise and generating socially valuable data to support the efficacy and safety of nipocalimab in severe HDFN. However, off-label use of antenatal intravenous immunoglobulin (IVIg) in standard-risk FNAIT pregnancies made a randomized placebo-controlled study challenging. Thus, the FNAIT clinical program for nipocalimab in pregnant persons with standard-risk FNAIT includes a randomized, placebo-controlled study limited to sites that do not use antenatal IVIg, and a global randomized open-label study of nipocalimab or IVIg.Knowledge of the clinical course and management of severe HDFN and FNAIT, the non-clinical and non-pregnant human clinical evidence, and input from physicians, patients, and health authorities permitted the design of clinical protocols that satisfy the principles of beneficence and non-maleficence in these rare and complex diseases. · Ethical principles apply to pregnancy-related disorders affecting fetal well-being.. · Placebo-controlled randomized trials in HDFN are based on equipoise.. · FNAIT programs must account for the off-label use of IVIg..