Placental hypervascularity does not cause perinatal brain injury

Abstract

Dizygotic twins at 38 weeks with separate placentas: twin A, a 2479 gram female, was healthy after vaginal delivery. Five minutes later when the amnion of twin B was ruptured artificially, the cord prolapsed and could not be repositioned. Some 25 minutes later a 2791 gram male was delivered by section. Brain injury was noted soon afterward and subsequent development was marked by severe cerebral palsy and mental retardation. Initial diagnosis of twin B's placenta was 'chorangiosis,' overlooking fresh thrombi blocking the umbilical vein and one umbilical artery. Subsequent assessment revealed the same change in twin A's placenta. Archival records had 18/500 (3.6%) stillborns and 17/418 (4.07%) newborns with central placental hypervascularity. Of 125 recent consult placentas there were 17/100 singleton and 11/25 (44%) twin placentas displaying this change. Of 229 section deliveries there were 0/42 stillborns and 5/187 newborns with this vascular pattern. Another set of 625 autopsies revealed none with both hypoxic encephalopathy and this placental finding. This structural change is the same often seen in placentas from high altitude such as in Denver. Cerebral palsy occurs less often in Colorado than in other American states, per epidemiological data.