A physiologic model of the dehydroepiandrosterone to estrogen conversion system in the fetoplacental unit. II. Preliminary clinical application--the dehydroepiandrosterone loading test

Metabolism of dehydroepiandrosterone (DHA) in the mature perfused human placenta (I)

A design for the perfusion of one (monoperfusion) or two (parallelperfusion) cotyledos of one placenta was developed for studies of the metabolism of the precursor steroid dehydroepiandrosterone (DHA). Several parameters are used as viability criteria: vascular resistance, glucose and oxygen consumption, lactate/pyruvate ratio, activity of lactate-dehydrogenase (LDH) in the perfusate, extent of perfusion by dye infusion, and morphological description by electron microscopy. A dosage of 2 mg DHA with 2.5 microCi 14C-radioactive labelled marker is given for testing the metabolizing capacity of the placenta. The labelled metabolites DHA, androstenedione (A), testosterone (T), estrone (Oe 1), and estradiol-17 beta (Oe 2) are separated by thin-layer chromatography and measured by scanning and measurements of scraped radioactive spots by scintillation counting. The steroidogenesis is evaluated with the concentrations of Oe 1 at 15 min (Oe 1.15'), Oe 1 + Oe 2 at 90 min (Oe tot, 90'), total aromatization rate (from perfusate and homogenate after 120 min). Results comparable to DHA are found using DHA-sulphate (DHA-S) as precursor, higher amounts of estrogens are metabolized from A. Mature placentas metabolize DHA in relation to the initial DHA concentration: optimal aromatization is found at 250-350 pmol DHA/ml/g, decreased aromatization at higher or lower concentrations. Oe 1 represents the main placental metabolite.

Cervical ripening with dehydroepiandrosterone sulphate

Dehydroepiandrosterone sulphate (DHEA-S) was given intravenously twice a week after 38 weeks gestation to ripen the uterine cervix in 20 nulliparae and 24 parous women who subsequently went into labour at term. The condition of the uterine cervix was assessed by Bishop scoring. The increase in the score in nulliparous women given DHEA-S was significantly greater than that in the control group, who were given placebo injections, on the 7th, 14th and 21st days. The increase in the parous women was significant only on the 7th day. In nulliparous women the dilatation, effacement and consistency improved significantly, while in the parous women the effect of DHEA-S was apparent only in the consistency. The duration of labour was significantly shortened by treatment with DHEA-S in nulliparae but this effect was not found in parous women. The interval between the first administration of DHEA-S and the onset of labour in nulliparae was significantly shorter than that in the control group. There were no serious side effects or complications. Our results suggest that DHEA-S may be used safely and effectively to ripen the uterine cervix and to trigger the onset of labour in late pregnancy.

The dehydroepiandrosterone loading test. IV. Evaluation of clinical utility

This report complements the previously described preliminary clinical evaluation of the dehydroepiandrosterone (DHEA) loading test (DLT) by presenting the results of 65 DLTs in 59 patients. In patients whose fetuses were suspected of being intrauterine growth retarded, a DHEA to estrogen conversion rate constant less than or equal to 3.0 x 10(-3) min(-1) was associated with a birth weight below the tenth percentile in 60% of the pregnancies, whereas a conversion rate constant above this threshold was not associated with the same degree of growth retardation. The DLT continues to qualify as an accurate predictor of pregnancy outcome as judged by birth weight. Although it seems to be too cumbersome to serve as a screening technique, the DLT will permit evaluation of the efficacy of various pregnancy interventions directed toward improvement of the intrauterine environment, such as bed rest, tocolysis, or antihypertensive medication.

The causes of low oestrogen excretion in pregnancy: assessment of the fetal contribution by steroid measurements post partum

Oestrogen levels in urine from 21 normotensive and 13 hypertensive pregnant women were moderately correlated (r = 0.48) with levels of 3 beta-hydroxy-5-ene steroids (oestrogen precursors) in urine from their infants. In five infants from otherwise normal pregnancies in which oestrogen excretion was very low, levels of 3 beta-hydroxy-5-ene steroids were significantly lower than normal while there was no difference between hypertensives and normals. Levels of urinary cortisol metabolites in the infants were moderately correlated with 3 beta-hydroxy-5-ene steroids (r = 0.55) and were especially low in 2 out of 5 infants in the series suffering from distress during delivery. We conclude that subnormal fetal steroidogenesis rather than reduced placental metabolism is the most common cause of low oestrogen excretion of unknown aetiology. A factor in the increased perinatal risk in this group may be an associated insufficient cortisol synthesis by the fetus.

Intra-amniotic or intravenous injection of dehydroepiandrosterone sulphate: simultaneous changes in steroid levels in amniotic fluid and maternal serum

Levels of unconjugated oestradiol-17 beta (E2) and testosterone (T) and total oestriol (E3) were measured hourly to 6 h after intra-amniotic (i.a.) (100--200 mg) or intravenous (i.v.) (100 mg) injection of dehydroepiandrosterone sulphate (DHEA-S) in a series of twenty-six women with mid-trimester abortion. Amniotic fluid E2 and T levels were elevated significantly 1--6 h after the i.a. injection of DHEA-S, while the E3 level in amniotic fluid did not change. The i.a. administration also induced significant rises in serum E2 and T levels between 1 and 6 h and in the serum E3 level between 2--6 h. The i.v. injection of DHEA-S was accompanied by significantly elevated serum levels of E2 and T, while the E3 concentration remained unchanged. It appears that following maternal i.v. administration or an amniotic fluid injection, DHEA-S is rapidly converted to E2 and T, and these accumulate in both the maternal circulation and the amniotic fluid. E3, however, is formed only after i.a. administration of DHEA-S, and is selectively transported to the maternal blood.

The dehydroepiandrosterone loading test. III. A possible placental function test

The dehydroepiandrosterone loading test (DLT) has been used in a small population of normal and high-risk obstetric patients, to date, in an attempt to develop a dynamic test of placental function. In spite of its limited applications, it has shown reliability in discriminating, with statistical significance, between high-risk pregnancies that result in normally grown, undistressed infants, and high-risk pregnancies that result in infants showing signs of placental insufficiency. The present report expands the study population by presenting our data on 40 loading tests performed in 37 high-risk and normal obstetric patients. Results of 19 of these DLT's have been previously reported and are included herein for statistical analysis. The DLT utilizes an excess substrate load of dehydroepiandrosterone to assess the maximum capability of the placenta to convert it to estrogen. Although our previous report did not show false positive or negative results in the conversion rates, the present results (40 DLT's) found two (2 out of 17) false positives (12%) and two (2 out of 19) false negatives (11%). The highly significant correlation between DLT result and pregnancy outcome seen previously was preserved. In addition, the data of another five DLT's in four patients are presented. This group includes a pregnancy with a fetus with multiple congenital malformations, two patients with intrauterine fetal death, and a nonpregnant woman. The results are not included in the statistical analysis, but discussion of these results has interesting pathophysiologic implications.