FETAL SERUM ERYTHROPOIETIN IN TWIN PREGNANCIES WITH DISCORDANT GROWTH- A CLUE FOR THE PRENATAL-DIAGNOSIS OF MONOCHORIONIC TWINS WITH VASCULAR COMMUNICATIONS

Ten sets of diamniotic twins with discordant fetal growth (ultrasonogr aphic estimated fetal weight difference >25%) and abnormal amniotic fl uid volume were assessed for fetal serum erythropoietin concentration (Epo). Ah 20 fetuses had a percutaneous umbilical blood sampling perfo rmed between 21 and 33 weeks gestation, Three sets of twins were dicho rionic while 7 sets were monochorionic. In these 7 monochorionic sets a vascular communication between twins was demonstrated prenatally and postnatally, From 24 weeks gestation the smaller twin of the dichorio nic group had a higher serum Epo than its larger cotwin; the larger co twin's serum Epo was within normal limits for singleton controls. Ah f etuses with documented vascular communications had higher serum Epo co ncentration than singleton controls. These findings suggest that deter mination of fetal serum Epo in the large cotwin may be a clue to the d iagnosis of vascular communications between twins with discordant grow th.