Vertical transmission
Vertical transmission is the passage of an infectious agent from a pregnant person to an embryo or fetus, or to a newborn during or after birth.
Transplacental transmission: Passage of an infectious agent across the placenta from a pregnant person to an embryo or fetus. This route allows infection before birth when an agent crosses the placental barrier.
HIV: Human immunodeficiency virus is a virus that attacks immune cells and can cause AIDS. HIV can pass during pregnancy, birth, or breastfeeding, and interventions greatly reduce transmission.
Maternal infection: An infectious disease present in a pregnant person during pregnancy or around childbirth. Vertical transmission begins with an infection in the pregnant person, though transmission is not inevitable.
Congenital anomalies: Structural or functional differences present at birth that arise during prenatal development. Some infections disrupt development and produce anomalies, especially during sensitive stages.
Maternal vaccination: Vaccination during pregnancy to protect the pregnant person, the fetus, or the newborn. Vaccines can prevent maternal infection or transfer protective antibodies, but options differ by pathogen.
Intrapartum transmission: Transmission of an infectious agent to a newborn during labor or delivery. Exposure to blood, secretions, or genital fluids can infect the newborn during birth.
Cytomegalovirus: Cytomegalovirus is a herpesvirus that can cause congenital infection and lifelong complications. Primary infection or reactivation during pregnancy can expose the fetus through the placenta.
Embryo: An early stage of human development before the end of the eighth week after fertilization. Infection at this stage can disrupt organ formation.
Stillbirth: The death of a fetus before or during delivery after a defined stage of pregnancy. Severe maternal infections can cause fetal death or pregnancy loss.
Congenital infection diagnostics: Tests used to identify infection in a pregnant person, fetus, placenta, or newborn. Timing and test accuracy determine whether infection is detected early enough to guide care.