[Placental immunoglobulin transfer]

Placental immunoglobulin transfer is an active process that involves the FcRn receptor and is particularly intense during the last trimester. The transferred immunoglobulins reflect the mother's immunological experience, and allow passive immunity to the fetus and to the newborn during the first months of life. The neonatal protection conferred by placental immunoglobulins transfer is optimized by term delivery, normal maternal titers of total immunoglobulins, adequate maternal specific immunoglobulin titers, antigen immunogenicity, and a healthy placenta. The infant's protection can be reinforced by maternal vaccination, especially if there is a threat of life-threatening infantile disease and/or if vaccination during the first few months after birth is contraindicated. Better knowledge of placental immunoglobulin transfer mechanisms allow a more accurate management of biotherapies during pregnancy.