What are the effects of chorioamnionitis on babies?

Depends. "chorio" is an infection in the membranes surrounding the baby, usually near delivery. Mom will often run a fever. This does increase the risk of infection spreading to baby, but usually with good obstetric care including intravenous antibiotics for mom, the baby will be fine. Sometimes right after birth blodo tests will be done on baby to see if signs of infection.
Chorioamnionitis... ...Is a bacterial infection of the "water" in which the baby is immersed during gestation. Because this "water" goes all through the lungs and the GI tract, chorioamnionitis means the baby has an infection right at birth, and needs to be treated immediately.
Infection. Infection than can be severe in a newborn that does not have good defenses.