Fetal Immunity

Fetal immunity is a dynamic process in which the immune system develops and matures during pregnancy while maintaining tolerance toward the mother. Maternal factors, including antibody transfer, microbial exposure, cytokines, placental inflammation, and gut microbiota, influence fetal immune development. Maternal IgG transferred through the placenta provides passive protection, while colostrum and breast milk provide additional immune protection after birth. The neonatal immune system remains functionally immature, particularly in innate and adaptive immune responses, making newborns more susceptible to infections. Understanding fetal and neonatal immune development is important for improving maternal care, neonatal protection, and vaccination strategies.