amnionitis

noun

am·​ni·​o·​nit·​is ˌam-nē-ə-ˈnī-təs 

: inflammation of the amnion typically due to infection

Organisms that inhabit the cervix, vagina, or rectum can spread upward into the amniotic cavity through intact or ruptured membranes and cause amnionitis.

—Richard A. Polan et al., in Avery's Diseases of the Newborn

also : chorioamnionitis

Oligohydramnios is frequently associated with chorioamnionitis (amnionitis), an infection of the membranes that surround the baby …

—Sandy Jones and Marcie Jones, Great Expectations: Your All-In-One Resource for Pregnancy & Childbirth