[Concentration of serum unconjugated estriol and estetrol in pregnant women with intrauterine growth retardation, and significance of these hormones in pregnancy (author's transl)].

Recently, estetrol (15 alpha-hydroxyestriol, E4) has been suggested to be a better indicator of fetal well-being than estriol (E3). In normal pregnancy, the concentration of unconjugated E3 and E4 in serum gradually increased as pregnancy progressed, and especially, rapidly increased in the third trimester. The patients with IUGR were classified in three groups. In the first group with mild pregnancy complications or none, serum E3, E4 and urine E3 almost changed in normal range. In the second group with severe pregnancy complications, only serum E3 changed almost in normal range, but urine E3 shows in low levels and serum E4 in high levels. In the third group with perinatal death of neonate, these three hormone levels was remarkedly low, especially in serum and urine E3. The highest E3 value in 51 pregnant women, significantly correlated with placental weight, birth weight and body length of neonate, and highest E4 significantly correlated with birth weight and chest circumference of neonate. The results signified that E3 predominantly indicated placental function, E4 also fetal function.