 It is a choice between expectant management and active management.An example is congenital cystic adenomatoid malformation with hydrops; impending heart failure may require a preterm delivery.Severe oligohydramnios of early onset and long duration, as can occur with early preterm rupture of membranes, can cause increasingly severe PH; if delivery is postponed by many weeks, PH can become so severe that it results in neonatal death.