SERUM ERYTHROPOIETIN IN SMALL-FOR-GESTATIONAL-AGE FETUSES

Serum erythropoietin (Epo) concentration was compared prenatally in ad equate (AGA) and small for gestational age (SGA) fetuses. Fifty-four p ercutaneous umbilical blood samplings were paired with maternal blood and assessed for Epo, hematocrit and reticulocyte count. Seventeen fet uses were growth-retarded (SGA) on the basis of ultrasonic biometry an d birth weight. Controls (AGA; n = 37) underwent cordocentesis for ris k of toxoplasmosis, maternal age or malformations (CNS, GI, heart). No cytogenetic abnormality or infections was found in the 54 fetuses. Li near and polynomial regressions were fitted to determine correlations between parameters. Nonparametric Mann-Whitney test was used for compa rison between groups. Gestational age at sampling was similar in AGA a nd SGA. The SGA fetuses had a higher Epo concentration than controls ( p < 0.001). Fetal AGA Epo increased significantly throughout pregnancy (p < 0.01) but did not correlate with maternal Epo (p > 0.05). An inv erse correlation was found between fetal reticulocyte count and Epo co ncentration (p < 0.02). The mechanism of high Epo level in SGA fetuses may involve low pO(2) and hemoconcentration.