Evaluation of azoestriol antisera for estriol measurements in pregnancy plasma directly and after extraction

Antepartum fetal surveillance in diabetic pregnant patients

The antepartum fetal surveillance (biochemical and biophysical) data of 140 pregnant diabetic patients were evaluated. We determined how often intervention occurred on the basis of abnormal tests and correlated each test with neonatal outcome. Fifteen of the total 140 patients had their pregnancies terminated because of abnormal biochemical and/or biophysical tests. An abnormal estriol (E3) value preceded the abnormal antepartum fetal heart rate testing in eight of 10 instances. We conclude that the major benefit of the antepartum fetal surveillance techniques, in this group of patients and under the present scheme, is in determining when not to intervene, thus allowing safe prolongation of pregnancy.

A direct radioimmunoassay for estriol-16alpha-glucosiduronate: its use in the determination of plasma and urine levels and renal clearance of this conjugate in pregnancy

A direct radioimmunoassay which does not require hydrolysis or chromatography has been developed for estriol-16alpha-glucosiduronate in pregnancy plasma and urine. The antigen used in the development of this antiserum was prepared by joining the carboxylic acid group of estriol-16alpha-glucosiduronate covalently to the epsilon-amino group of the lysine residues in bovine serum albumin. Results indicate that the direct radioimmunoassay yields levels of estriol-16alpha-glucosiduronate in late pregnancy urine that are comparable to those obtained by mroe elaborate procedures involving chromatographic separation of the estriol conjugates, followed by enzymic hydrolysis and measurement of the freed estriol. In addition, good correlation was found between the total estrogen values in urine obtained by currently used chemical procedures and urinary levels of estriol-16alpha-glucosiduronate. The renal clearance of estriol-16alpha-glucosiduronate was determined in eight normal women during the third trimester, and the mean value +/- S.D. was 404 +/- 81 ml. per minute (range, 248 to 494). This method is suitable for the evaluation of variations in the plasma and urine levels of estriol-16alpha-glucosiduronate in pregnancy and offers significant advantages over the presently used chemical methods for monitoring fetal well-being.

Plasma unconjugated estriol values in high-risk pregnancy

The usefulness of plasma estriol concentrations in the management of high-risk pregnancy is controversial. In this study, serial plasma unconjugated estriol (E3) concentrations determined by radioimmunoassay were evaluated in 321 patients with high-risk pregnancy for correlation with fetal and neonatal performance. A plasma E3 concentration of 4 ng. per milliliter or less in late pregnancy correlated significantly with low one-and five-minute Apgar scores and selected neonatal problems in pregnancies complicated by chronic hypertension and intrauterine growth retardation, with a similar trend for pregnancies complicated by moderate and severe pre-eclampsia. Most perinatal deaths in the study were associated with acute problems which began during labor and delivery, or fetal death occurred before early intervention was practical. Therefore, the perinatal mortality rate is not likely to be influenced by the use of E3 values, and the perinatal mortality rate is not a realistic measure of the usefulness of plasma E3 values in management of high-risk pregnancy. Low plasma E3 values were not always ominous, and for this reason it is suggested that clinical indications and the results of other tests for fetal-placental function be considered along with plasma E3 values in the selection of patients for early delivery to reduce the possibility of inappropriate intervention.