Neonatal consequences of placental and membrane dysfunction

Abstract

Early amnion rupture is a sporadic event that results in mechanical teratogenesis due to amniotic-band disruption and/or compression. It may cause abortion or stillbirth, craniofacial clefts, and cerebral, body wall and limb/skeletal defects. Prolonged and premature rupture of membranes and oligohydramnios result in the dry-lung syndrome and pulmonary hypoplasia. The risk of chorioamnionitis is also increased, with serious consequences to the fetus and neonate. Placental lesions are associated with fetal growth retardation, preterm birth, fetal malformations and other neonatal disorders (congenital infections, erythroblastosis, alpha thalassaemia). In particular, the impact of extremely preterm births on perinatal mortality rates and health costs is substantial. The 1-year survival rate of singleton infants born at the Monash Medical Centre was 10% at a gestation period of 23 weeks, 37% at 24 weeks, 42% at 25 weeks, 61% at 26 weeks and 78% at 27 weeks (11% at birthweights of 500-599 g, 30% at 600-699 g, 55% at 700-799 g and 71% at 800-899 g). Proven measures to minimize the neonatal consequences of extremely preterm delivery include in utero transfer of at-risk fetuses to a perinatal centre and antepartum corticosteroids. Research into the pathophysiological basis of placental and membrane dysfunction may help reduce the prematurity rate.