Amniotic fluid estriol, estriol precursors, and pregnanediol in intrauterine growth retardation

Abstract

Conjugated estriol, 16α-hydroxy DHA, 16-ketoandrostenediol and pregnanediol were determined by gas chromatography in amniotic fluid samples collected in 12 pregnancies with fetal intrauterine growth retardation (IUGR) and in a reference group of 50 pregnancies with undisturbed fetal growth. Amniotic fluid estriol concentration was also correlated to maternal urinary estriol excretion in both groups. A statistically significant positive correlation between amniotic fluid concentration of conjugated estriol and maternal urinary estriol excretion was found in the reference group but not in the IUGR group. A low amniotie fluid estriol level was found in three of the 12 IUGR pregnancies, whereas simultaneous maternal urinary estriol excretion was decreased in eight of the IUGR cases. The total concentrations of 16α-hydroxyDHA and 16-ketoandrostenediol correlated with the concentration of estriol in amniotic fluid samples both in the reference and IUGR group. Concentrations of pregnanediol found in the IUGR group were within the 95% confidence limits obtained for the reference group. In six of the 12 IUGR pregnancies abnormal fetal heart rate pattern indicated a more severe insufficiency of placental function. In five of these cases amniotic fluid estriol level was normal and in one case it was abnormally high. According to these results amniotic fluid estriol concentration poorly reflected fetal condition in IUGR pregnancies.