Which type of transmission involves passing infections from a pregnant mother to her child?

Vertical transmission refers to the transfer of infections from a pregnant mother to her child, typically during pregnancy, childbirth, or breastfeeding. This type of transmission is particularly significant because it can lead to congenital infections, where the newborn may be born with the infection or develop it shortly after birth. Conditions like syphilis, HIV, and rubella can be transmitted in this manner, making it crucial for healthcare providers to monitor and manage infections in pregnant patients to protect both the mother and the child.

Horizontal transmission, on the other hand, involves the spread of infections between individuals who are not in a mother-child relationship, typically through direct contact or via respiratory droplets, which differentiates it from the maternal-to-child transmission of vertical transmission. Indirect transmission involves the spread of pathogens through intermediate objects or vectors that do not involve direct person-to-person contact, while vector transmission specifically refers to the spread of infection through insects or other animals rather than from mother to child. This clarity in the distinction among transmission types highlights why vertical transmission is the correct answer in this context.