FETUSES FROM PREECLAMPTIC MOTHERS SHOW REDUCED HEPATIC ERYTHROPOIESIS

The fetal liver is the main hematopoietic organ during intrauterine li fe. Morphometrical studies were performed on liver sections to detect changes occurring with intrauterine growth retardation and preeclampsi a. Compared with the controls (n = 10), fetuses from preeclamptic moth ers showed a severe reduction of erythroid cells by 60% on average (n = 18). Closer examination revealed that the erythroid cells at early s tages of differentiation were more affected (80% reduction) than at la ter stages (55%). Seven out of 18 fetuses from preeclamptic mothers di d not show growth retardation but exhibited severely reduced hepatic e rythropoiesis. We suggest that the prime factor for impaired red blood cell production is preeclampsia itself rather than intrauterine growt h retardation. Regulation of erythropoiesis in utero might depend on t he interaction of many hematopoietic ,growth factors, and preeclampsia might alter the balance. To test this notion, we quantitated erythrop oietin in fetal blood and various cytokines in the amniotic fluid. An elevation of erythropoietin and interleukin (IL)-3 levels was seen in babies born under the conditions of preeclampsia, whereas the concentr ations of granulocyte/macrophage-colony-stimulating factor (CSF), gran ulocyte-CSF, and IL-1 beta were reduced, and the levels of IL-6 and IL -8 remained constant. With preeclampsia, a discrepancy between elevati on of erythrocyte numbers in peripheral blood and depression of hemato poiesis at the main production site, the fetal liver, is seen. Concomi tantly, there is elevation of some but reduction of other hematopoieti c cytokines. We envision that during the course of preeclampsia quanti tation of hematopoietic growth factors might allow to predict the dete rioration of in utero life conditions.