Final answer:
Chorioamnionitis is a major threat after preterm rupture of membranes.
Step-by-step explanation:
The major threat after preterm rupture of membranes is chorioamnionitis.
Chorioamnionitis is an infection of the placental membranes and amniotic fluid. It can occur when the amniotic sac ruptures prematurely, providing a pathway for bacteria to enter the uterus and infect the fetus. Chorioamnionitis can lead to serious complications for both the mother and the baby, including preterm labor, sepsis, and respiratory distress syndrome.