Trophoblast deportation in pre‐eclamptic pregnancy

OBJECTIVES: To examine the deportation of trophoblast cells into the maternal blood in pre-eclamptic (gestational proteinuric hypertension) and normal pregnancy. DESIGN: The monoclonal anti-cytokeratin antibody JMB2 was used in the APAAP technique to label trophoblast cells in cell smears of uterine vein blood obtained at caesarean section. SUBJECTS: 10 women with proteinuric pre-eclampsia requiring caesarean section, 10 pregnant women requiring elective caesarean section for reasons other than pre-eclampsia and five control women who had never been pregnant. RESULTS: Three populations of trophoblast cells were identified; two mononuclear cytotrophoblast types with diameters varying from 11-14 microns and 19-25 microns respectively, and multinucleated syncytiotrophoblast cells varying in size from 23-88 microns. Women with pre-eclampsia had more trophoblast cells in uterine vein blood than were found in pregnant women without pre-eclampsia. There was no correlation between the numbers of trophoblast cells and the stage of gestation or severity of the pre-eclampsia, although an acute maternal or fetal event necessitating delivery was associated with increased deportation of trophoblast. Mononuclear cytotrophoblast cells were detected in the peripheral blood of only 1 of 5 pre-eclamptic patients, despite their presence in the uterine vein blood of all 5 women. CONCLUSIONS: Trophoblast deportation is increased in pre-eclamptic pregnancy, with both cytotrophoblast and syncytiotrophoblast present in the uterine vein blood, but there is no correlation with the severity of the disease. In some cases cytotrophoblast may also enter the peripheral circulation.