Doctors routinely screen for certain infections during pregnancy because many infections can readily pass from a mother to her baby. Bacteria, viruses, and protozoa are all culprits. This transmission can occur in several ways:
- organisms in the mother's bloodstream can cross the placenta and infect the baby;
- organisms in the mother's vagina or genital area can move up the vagina and into the uterus;
- during delivery, the virus can be transmitted to a baby through infected secretions in the birth canal; and
- after delivery, a baby can be infected through close contact with the mother or through her breast milk.
Depending on the infection involved, transmission from mother to baby can lead to premature delivery, anemia, pneumonia, sepsis (pathogenic organisms or toxins infecting the blood or tissue), central nervous system problems, growth retardation, HIV, and other complications. Some infections can lead to death.
M any infections during pregnancy can dramatically increase the risk of preterm delivery, which is the leading cause of complications and death in newborn babies.