Correlation of oestriol levels in saliva, plasma and urine of pregnant women

Unconjugated and total oestriol (E3) have been determined in saliva (S) and plasma (P) by radioimmunoassay using a highly specific antiserum against E3. Total oestrogens (E = E1 + E2 + E3) in urine were analysed by the Kober-Ittrich method. No correlation (P greater than 0.05) was found between unconjugated E3 (S) and total E (U) as well as total E3 (S) and total E (U). Total E3 (S) and unconjugated E3 (P), total E3 (S) and total E3 (P) correlated weakly (P less than 0.05 and greater than 0.01). The six remaining correlations were highly significant (P less than 0.001 or less than 0.0001).

An enzyme-linked immuno sorbent assay for salivary estriol during normal pregnancy

It has been recently demonstrated that the concentration of Estriol in saliva increases in the course of pregnancy, similarly to the plasmatic concentration of unconjugated and total Estriol. As an alternative to RIA, which is an expensive method and requires a highly specialized laboratory, there is now available a competitive, sensitive and rapid enzyme-linked immuno sorbent assay (ELISA) for Estriol in saliva and plasma. Aim of this study is to compare the levels of Estriol concentration, measured by RIA and by ELISA in saliva and plasma in seven women tested every week from the 30th week to the term of pregnancy.

Correlation of concentrations of estriol-3-sulfate with those of potassium and sodium in human breast cyst fluid

Estriol-3-sulfate (E3-3S) was assayed in 92 specimens of human breast cyst fluid (BCF) obtained by needle aspiration from women with fibrocystic disease. The concentrations of K+ and Na+ were determined in the same samples. The median concentration of E3-3S in the fluids from premenopausal women under 51 years of age (69 cases) was 4.4 ng/mL. Based on the K+ levels the samples were divided into two groups, above 50 mM (Type I) and below 50 mM (Type II). Correlations were made between the concentrations of the estrogen conjugate and the univalent ions. In the premenopausal women, Type I cysts were associated with above median E3-3S and Type II cysts with below median E3-3S (P less than 0.01). A K+/Na+ ratio of more than one was also related to elevated E3-3S (P less than 0.025). The BCF obtained from postmenopausal women and women older than 50 years tended to be low in E3-3S (median 1.64 ng/mL) and high in K+ but there were too few cases to permit statistical comparisons to be made. Since fibrocystic disease constitutes a risk factor for the development of breast cancer, it will be of interest to determine retrospectively whether any of the above subsets of BCF may be useful in identifying a patient at such risk.

Immunoreactive oestrogens and progesterone in amniotic fluid in twin pregnancies

Amniotic fluid concentrations of immunoreactive oestrogens and progesterone were measured at the time of caesarean section in 32 twin pregnancies; 25 women had an elective section and seven were in labour at the time of operation. No significant differences between concentrations in the amniotic fluid of the first and second twin were found in respect of conjugated and unconjugated oestrone, oestradiol, oestriol, oestetrol and unconjugated progesterone either before or during labour. It is unlikely that changes in oestrogens or progesterone in the amniotic fluid are responsible for the selective changes seen in prostaglandins and fetal adrenal steroid during labour in the first twin.

Placental protein and hormone measurements in twin pregnancy

Maternal serum levels of human placental lactogen (hPL), schwangerschaftsprotein 1 (SP1), pregnancy-associated plasma protein A (PAPP-A), placental protein 5 (PP5) and total oestriol (E3) were measured serially in 35 twin pregnancies during the third trimester. Eighteen pregnancies had major complications including dysmaturity of one or both fetuses in nine, premature labour in six, and placental abruption in three. Serum levels of all five variables were higher than in singletons, this distinction being greatest for hPL and lowest for SP1 and E3. The levels of hPL, PP5 and E3 just before delivery were significantly correlated with the total birthweight, a correlation with placental weight being evident only for hPL and PP5. A significant correlation between the five biochemical variables at 33-34 weeks was only seen between hPL and PAPP-A. Protein and hormone levels in the abnormal twin pregnancies were not apparently different from those in the normal twin pregnancies. These data suggest that only hPL levels biochemically reflect this extreme of fetal and placental growth, but that neither the levels of hPL nor any of the other biochemical indices examined are altered in abnormalities in twin pregnancy.

Automated continuous-flow radioimmunoassay for salivary estriol

We have automated a radioimmunoassay for salivary estriol by using the "Southmead" continuous-flow system. The assay, based on a well-validated manual assay, involves a Sepharose-coupled antiserum and an 125I-radioligand. The antibody-bound and free radioligand fractions are separated by on-line filtration. Performance of the automated assay has been reliable during six months of regular use, and compares favorably with that of the manual assay. Drift (0.5 nmol/L per 100 samples) and sample carryover (3%) are acceptable, and the throughput rate is 55 samples per hour. The system is suitable for the assay of the large numbers of samples generated by daily saliva specimen collection in the third trimester of pregnancy.

Preparation of specific antiserum to estriol 3-sulfate 16-glucuronide

The preparation and antigenic properties of estriol 3-sulfate 16-glucuronide-bovine serum albumin (BSA) conjugate in which the hapten is linked to the carrier through an (O-carboxymethyl)oxime bridge at the C-6 position on the steroid nucleus, have been described. Coupling of 6-oxoestriol 3-sulfate 16-glucuronide acetate-methyl ester 6-(O-carboxymethyl)oxime with BSA by the activated ester method followed by removal of the protecting groups with alkali provided the desired conjugate. The antisera raised against the conjugate in rabbits were highly specific to the double conjugate, estriol 3-sulfate 16-glucuronide, discriminating from ring A or D monoconjugated and unconjugated estrogens. The specificity of antisera elicited has been discussed on the basis of stereochemistry of the hapten-[C-6]-BSA conjugate.

ELISA for salivary and plasma estriol in pregnancy

A competitive, sensitive, and rapid enzyme-linked immunoadsorbent assay (ELISA) was developed for the determination of estriol in saliva and in plasma. Horseradish peroxidase (HRP) was used as the label enzyme; separation between free and bound steroid was carried out by insolubilized antibody prepared by adsorbing purified IgG of rabbit anti-6-oxoestriol-6-(O-carboxymethyl)oxime-BSA on polystyrene balls. The enzyme activity was measured by a colorimetric reaction using o-phenylenediamine dihydrochloride and hydrogen peroxide as substrate. The sensitivity of the assay was 12 pg/tube. In order to compare ELISA to RIA estriol estimations in different biological fluids, we selected six women during normal pregnancy, from the 30th to the 40th week of gestation. Salivary estriol was assayed by direct and extraction methods, while the corresponding plasma samples of the same subjects were analyzed only for unconjugated estriol by an extraction method. A good agreement was found between the results obtained by RIA and ELISA: r = 0.897, p less than 0.001 between direct RIA and direct ELISA in saliva; r = 0.909, p less than 0.001 between extraction RIA and direct ELISA in saliva; and r = 0.916, p less than 0.001 between extraction RIA and extraction ELISA in plasma. A good correlation (r = 0.793, p less than 0.001) was present between plasma samples by RIA and saliva samples by ELISA (direct method). These results indicate that: ELISA is a reliable method for the determination of estriol in plasma and saliva. Saliva samples can be used for the assay of estriol and therefore for the assessment of fetal conditions during pregnancy.

Correlation of amniotic fluid estrogens with L/S ratios and urinary estriols

17 beta-estradiol (E2) and estriol-16-glucuronide in amniotic fluid from 87 patients (normal and stressed pregnancies) were studied with radioimmunoassays. Overall, amniotic fluid estradiol and estriol increased with gestation and paralleled the increase in the L/S ratio. Statistical correlations between amniotic fluid E2 and E3 with L/S were fair and better for E3 than for E2. Correlations were better from 31 to 35 weeks of gestation than from 36 to 40 weeks. A threshold of 0.34 ng/ml should be used for E2; levels above that possibly represent fetal maturity and well-being. A threshold of 540 ng/ml should be used for E3; levels above that possibly indicate fetal maturity and wellbeing. Urine E3 correlated poorly statistically with amniotic fluid E3. Serum E3 was not studied.

Estriol in human breast cyst fluid

Although cystic lesions of the breast are not precancerous per se, statistical studies have indicated that this condition predisposes a 2- to 4-fold greater risk for breast cancer. Seeking a hormonal etiology to this correlation, investigators have analyzed breast cyst fluid ( BCF ) for steroids and have compared the levels to those in the blood. The 17-ketosteroids-androsterone, dehydroisoandrosterone and their sulfates are elevated in BCF . The same is true for estrone sulfate and estradiol-3-sulfate. We have found the most dramatic differences with estriol-3-sulfate (E3-3S), the concentration of which ranged from 187-6134 pg/ml in over 40 specimens analyzed, whereas in 12 serum specimens from normal women, E3-3S was barely detectable. The origin of E3-3S is not known. [3H]E3-3S is not concentrated in BCF following its injection into an arm vein. The blood half-life of [3H]E3-3S is much lower than that of estrone sulfate. Samples of breast nipple aspirates from normal women were also analyzed for E3-3S. None could be detected. The best explanation of the data accumulated thus far is that E3-3S is synthesized at the epithelial lining of the cyst and released into the BCF , from which its efflux is inefficient.

Specific antisera for the radioimmunoassay of estriol 3-sulfate

Antisera were raised in male guinea pigs against 6-oxoestriol 3-sulfate O-carboxymethyloxime-bovine serum albumin (BSA) conjugate. The antisera to this antigen exhibited high affinity (Ka=4.7 X 10(9)M-1) and excellent specificity for estriol 3-sulfate, showing slight cross-reactions (less than 0.43%) with other estrogen sulfates, and no cross-reactivities with free estrogens and other steroids (less than 0.01%) except cholesterol sulfate (0.22%). A standard curve using [6, 7-3H]-estriol 3-sulfate as the radioactive ligand showed high sensitivity in the range of 10-1000 pg estriol 3-sulfate.

Preparation of specific antisera to estrone-3-glucuronide and estriol-3-glucuronide

The preparation and antigenic properties of estrone-3-glucuronide- and estriol-3-glucuronide-bovine serum albumin conjugates in which the hapten is linked to the carrier protein through an (O-carboxymethyl)oxime bridge at the C-6 position on the steroid nucleus, have been described. Antibodies raised against the two immunogens in the rabbit possessed high specificity to estrone-3-glucuronide and estriol-3-glucuronide, respectively, exhibiting little cross-reactivities with other estrogen conjugates and no cross-reactions with related steroids except for free estrogens, their 3-methyl ethers and 3-sulfates. The cross-reactive antibodies were eliminated by partial immunoadsorption on affinity chromatographic media using the estrone-3-methyl ether 17-(O-carboxymethyl)oxime- and estriol-3-methyl ether 16 (or 17)-hemisuccinate-aminohexyl Sepharose conjugates, respectively. The purified antisera exhibited no cross-reactivities with free estrogens and ring A conjugates of estrone and estriol.

The role of nonstress tests, fetal biophysical profile, and contraction stress tests in the outpatient management of insulin-requiring diabetic pregnancies

Antepartum fetal surveillance methods applicable in a home glucose-monitored population of pregnant diabetic women have been evaluated. A testing sequence of nonstress heart rate testing, backed up by either the fetal biophysical profile or contraction stress testing employed at a twice weekly interval, in 107 outpatients was compared with the management of 140 historic control patients by weekly nonstress tests and daily plasma estriols. There were 617 of 672 (91.8%) reactive nonstress tests in outpatients compared to 566 of 626 (90.4%) reactive tests in hospitalized control patients. Of 13 contraction stress tests performed in the outpatient group, only one was positive. Although 2,670 estriol determinations were done on hospitalized control patients, none was used for outpatients. No losses were attributed to unexplained antenatal stillbirth in either group. A fetal biophysical score of 8 was found to be at least as reliable as a reactive nonstress test. Antenatal surveillance in the well-controlled, insulin-requiring diabetic woman can be safely achieved with a testing sequence that consists of twice weekly nonstress tests backed up by the fetal biophysical profile and contraction stress tests.

Influence of sampling time on salivary oestriol concentrations in pregnant women

Saliva specimens were collected at weekly intervals during the third trimester of 61 uncomplicated pregnancies. Oestriol concentrations, measured in samples collected in the early morning from fasting, recumbent subjects, were used to construct a provisional normal range. This proved to be higher than the corresponding normal range reported from another laboratory applying the same method to samples obtained at random from a different population of ambulant subjects. Interlaboratory variation in the assay of salivary oestriol was not sufficient to account for the difference in normal range. It is concluded that consideration should be given to the timing of sample collection if salivary oestriol concentration is to be monitored as a possible means of assessing fetoplacental function. A normal range for salivary oestriol concentration versus gestational age obtained from women sampled randomly may not be appropriate for monitoring patients with 'at-risk' pregnancies who are normally bed-rested.

Salivary estriol concentrations during normal pregnancies, and a comparison with plasma estriol

Saliva would have advantages over plasma or urine for monitoring estriol during pregnancy. Specimen collection, after stimulation of flow by citric acid, is non-invasive and simple. We measured concentrations of unconjugated estriol in saliva and compared them with those in plasma in normal pregnancies, and found a good correlation (r = 0.79). In addition, trends of concentrations in saliva and plasma were statistically compared and found to be highly correlated. The variation among individuals in the saliva/plasma concentration ratio suggested that some inter-individual factor(s) may affect this relationship. The normal reference interval for unconjugated estriol concentration in saliva from 20 weeks of gestation to term was established.

Fetal sex dependent hormone levels in early pregnant women with elevated maternal serum alpha-fetoprotein

Maternal serum and amniotic hormone levels have been investigated in two groups of women in pregnancy weeks 18-21. One group (B) was composed of women with high alpha-fetoprotein levels in serum without fetal abnormality, and a matched control group (A) with normal alpha-fetoprotein levels in serum. Amongst group B women were four pregnancy complications: two spontaneous abortions, one premature delivery, and one cesarean section due to fetal asphyxia. Group B women were significantly different from group A women. Thus, higher maternal serum levels of total estriol (P = 0.030), testosterone (P = 0.016), and alpha-fetoprotein (P = 0.018) were noted in the presence of male fetuses; and higher hPL (P = 0.004), FSH (P = 0.037), and alpha-fetoprotein (P = 0.002) concentrations in women carrying female fetuses, who were accompanied by lower total estriol concentrations (P = 0.045). Differences between groups B and A in terms of amniotic fluid analyses were only related to female fetal sex. Thus, group B showed higher hPL (P = 0.028), testosterone (P = 0.020), and FSH (P = 0.006) levels, and lower alpha-fetoprotein (P = 0.013) concentrations. It is concluded that elevated maternal serum levels of alpha-fetoprotein are accompanied in female fetuses by an endocrine milieu different from that of matched controls. This difference may put the conceptus at a disadvantage, but the majority of the girls were born on time without signs of small-for-date.

Hormones in saliva: mode of entry and consequent implications for clinical interpretation

Assay of hormones in saliva would be more convenient than assay in blood, but there is no information on the route by which hormones enter saliva, information that would provide insight into the clinical value of such assays. We have examined the mode of entry of various hormones into saliva. The results suggest that unconjugated steroids enter saliva by diffusing through the cells of the salivary glands and that their concentration in saliva does not depend on the rate of saliva production. Conjugated steroids enter saliva via "ultrafiltration" through the tight junctions between the acinar cells, and their concentration in saliva is highly flow-rate dependent. Thyroxin and choriogonadotropin enter saliva via the ultrafiltration route or by contamination of the saliva by plasma or gingival fluid. We conclude that the salivary concentration of unconjugated steroids may usefully reflect the concentration of free (nonprotein-bound) steroids in plasma. Conversely, the concentration of conjugated steroids, thyroxin, and protein hormones such as choriogonadotropin in saliva probably does not reflect their concentration in plasma in any clinically useful way.

Source of analytic variation in ligand assay: a study based on data from the 1976 and 1981 Basic Ligand Assay Surveys of the College of American Pathologists

Six paired specimens distributed to laboratories in 1981 at approximately three-month intervals and four paired specimens distributed to laboratories in 1976 at intervals of three to nine months for analysis by the College of American Pathologists Survey form the basis for this study. Twelve of 37 (35%) of pool-analyte-technic combinations yielded significantly changed mean values in 1976, while 34 of 196 (17%) pool-analyte-technic combinations yielded significantly changed values in 1981. Probable instability in thyroxine and folate was demonstrated in the 1981 control pools. Precision generally continued to improve from 1976 to 1981. The poorest precision now is observed in the analysis of peptide hormones. A majority of the observed analytic variation during 1981 for most analytes relates to extralaboratory factors. Improvement in performance is largely dependent on intermanufacturer standardization of procedures and long-term maintenance of equivalence of the results of kit procedures by each manufacturer.

Characterization of the major steroids present in amniotic fluid obtained between the 15th and 17th weeks of gestation

In pooled amniotic fluid obtained between the 15th and 17th weeks of gestation the concentration of free steroids and steroid glucuronides was found to be 40 micrograms/dl. The concentration of steroid monosulfates and disulfates was 19 micrograms/dl. About half of the characterized steroids are progesterone metabolites. The "fetal type" 3 beta-hydroxy-5-ene steroids were found exclusively in the sulfoconjugated form. Their concentration represents 20% of the total steroid content. The identification of two 15 beta-hydroxylated C21 steroids, 3 beta,15 beta,17 alpha-tridoxy-5-pregnen-20-one and 5-pregnene-3 beta,15 beta,17 alpha,20 alpha-tetrol isolated from mid-pregnancy amniotic fluid is reported here. Metabolites of cortisol and 17-deoxycorticosteroid metabolites had similar quantitative importance, 8.6 and 9.4%, respectively.