Vertical transmission is the passage of disease from a mother to a child during the perinatal period that starts shortly before birth and extends to the time just after birth. Pathogenic organisms can pass from mother to child in a number of ways, and they are a concern in pregnancy. Women with conditions known to be transmitted vertically may need to take special precautions, especially in labor and delivery, to protect their babies.
Placental transmission is one potential way for an organism to leap between mother and child. The placenta provides vital nutrients to the baby and can also harbor disease if the mother is carrying an organism known to cause prenatal infections. During labor and delivery, vertical transmission can occur as a result of exposure to the mother's blood and other body fluids. Breast milk can also potentially be a vector of disease transmission.
Some organisms with a history of vertical transmission include the human immunodeficiency virus (HIV) and hepatitis C. Conditions like toxoplasmosis can cause birth defects if a mother becomes infected during pregnancy. When a woman gets pregnant, the doctor may recommend some testing to check for common risks, as well as precautions to prevent contraction of infections and subsequent vertical transmission. If a mother has a disease of concern, the doctor will discuss how best to manage the pregnancy and delivery.
In some cases, concerns about vertical transmission may lead a doctor to recommend a Cesarian section for delivery. This will limit stress during labor and delivery and reduce the chances of passing an infection on during this period. If a mother's breast milk is not safe, milk banking is an option to provide the baby with breast milk, or the doctor can discuss formula feeding. The best approach will depend on the situation and the infection at hand, and it can be helpful to consult a nutritionist to discuss feeding options.
Expectant mothers with worries about vertical transmission can take some steps to protect their babies. In mothers without any known infections, avoiding obvious sources of infection like badly handled food can reduce the chances of getting sick and passing the infection on to the baby. Mothers with active infections may be able to take medications to suppress them and protect their developing fetuses for as long as possible. It can also help to work with an obstetrician who has experience in this area for labor and delivery.