Objective: Systematic placental examination has the potential to shed light on poorly understood antenatal processes that may increase the risk of neurologic impairment and cerebral palsy.
Design: Using data from a retrospective case-control study, we analyzed placentas from 60 inborn, singleton, very low-birth-weight (<1.5 kg) infants delivered between 1983 and 1991 who had subsequent neurologic impairment at 20 months corrected age (42 with cerebral palsy and 18 with other neurologic abnormalities) and 59 control infants of comparable gestational age, birth weight, sex, and race. Three a priori hypotheses based on previous studies were that neurologic impairment would be increased with fetal vascular lesions with or without coexisting chorioamnionitis, decreased with chronic maternal vascular underperfusion, and increased when multiple placental abnormalities were seen in the same case.
Results and conclusions: We found 2 types of fetal placental vascular lesions to be associated with neurologic impairment, namely, recent nonocclusive thrombi of chorionic plate vessels (P < .04) and severe villous edema (P < .01). Chorionic plate thrombi were seen only with chorioamnionitis and accounted for the increased risk of neurologic impairment seen with chorioamnionitis. Maternal vascular lesions showed a biphasic relation to neurologic impairment in the subgroup of patients without chorioamnionitis. Mild lesions were increased in controls (inadequate vascular remodeling, P=.03, and accelerated maturation, P=.004). A more severe lesion, multiple villous infarcts, although not reaching significance, was increased in the neurologically impaired cases. Finally, in a test of 9 selected placental lesions, cases with cerebral palsy were more likely to have 2 or more lesions (P < .0001) and were less likely to have no lesions (P < .04) than control infants.