Hormonal studies in pregnancy. II. Unconjugated estriol in maternal peripheral vein, cord vein, and cord artery serum at delivery in pregnancies complicated by intrauterine growth retardation.

The levels of unconjugated estriol in maternal vein serum during labor, cord artery serum, and cord vein serum were measured in normal pregnancy and in pregnancy complicated by intrauterine growth retardation. The mean level of unconjugated estriol in maternal vein serum was significantly lower in the intrauterine growth-retarded group than in the normals (p less than 0.001). The mean estriol level in cord vein was lower only in the most severely growth-retarded subgroup as compared to the normal. There was no difference seen in the cord artery values among the groups.