The objective of this study was to determine if placental histopathology patterns are associated with clinical features of preterm pre-eclampsia. A 1989-1993 database of consecutive non-anomalous singleton livebirths delivered at 22-32 weeks gestation excluding cases of maternal diabetes mellitus and chronic hypertension included 74 cases of pre-eclampsia. Placentae were scored for uteroplacental vascular lesions and lesions of chronic inflammation and coagulation. Thirteen lesion patterns identified by factor analysis were studied in relation to the clinical features. Severe maternal proteinuria was related to placental chronic inflammation, while lower maternal antepartum platelet counts were related to placental abruption and infarct. Lower birthweight percentile and lighter placentae were related directly to uteroplacental vascular lesions. Diagnosis of HELLP and coagulopathy were less common when chronic inflammation scores were high. Serologic studies related to autoimmunity and maternal blood pressures were unrelated to placental histopathology factors. It is concluded that features of maternal and fetal compromise in preterm pre-eclampsia are related to placental histopathology patterns.