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Background: Light-initiated chemiluminescent assays (LICA) are homogeneous assays that are sensitive, specific, and free of separation and washing steps and have high throughput and high precision., Methods: In this research, we developed a competitive method by LICA to achieve accurate quantification of estradiol (E2) in human serum. E2 competed with estriol (E3) for binding to anti-human E2 antibodies. E3 was linked to biotin via bovine serum albumin as a linker. As this assay used competition between the labeled tracer and the analyte, an increase in E2 concentration will cause a signal decrease., Results: The expected detection range of E2 was 20-5000 pg/mL. The analytical and functional sensitivities were 7.16 and 13.7 pg/mL, respectively. The intra- and inter-assay coefficients of variation were both below 15%, and the recovery rate ranged from 97.5% to 106.8%. The interference rates ranged from -3.6% to 5.4% and met detection requirements for E2 in hyperbilirubinemia, hemolysis, and lipemia in clinical samples. In addition, the cross-reactivity rates between E2 and structural analogs and some reproductive hormones varied from 1.9% to 10.6% which showed that LICA is highly specific for E2. Moreover, our results showed high accordance with the IMMULITE 2000 (y = 0.6695x + 47.92, r 2  = .843) and VIDAS systems (y = 1.099x - 821.5, r 2  = .9392)., Conclusion: Our data show that the LICA, which is easy to automate, is a promising technique for quantification of E2 in human serum and could be used for clinical detection., (© 2019 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals, Inc.)

Objective: To estimate whether midtrimester maternal serum analyte concentrations differ between Caucasian and Hispanic women and whether using ethnic-specific medians affects quad screen performance., Method: Caucasian and Hispanic patients with singletons who underwent maternal serum screening in our laboratory were identified. Alfa-fetoprotein (AFP), estriol, human chorionic gonadotrophin (hCG), and inhibin-A medians were derived separately for Caucasians, Hispanics, and for the composite group. Using composite medians, intergroup mean multiples of the medians (MoMs) for each analyte were compared. Using ethnic-specific medians, new MoMs were calculated and utilized in a risk estimation algorithm., Results: A total of 5478 Caucasian and 2246 Hispanic pregnancies were evaluated. Intergroup MoMs were significantly different for all analytes. AFP, hCG, and inhibin-A were lower in Hispanics, while estriol was higher (P < 0.0001). Using composite medians, the screen-positive rate (SPR) for trisomy 21 was 5.39% in Caucasians and 3.29% in Hispanics. Ethnic-specific medians reduced this disparity: 4.76% in Caucasians and 4.05% in Hispanics. The SPR for neural tube defects with composite medians was 1.44% for Caucasians and 0.89% for Hispanics; with ethnic-specific medians, the SPR was 1.42% for Caucasians and 1.07% for Hispanics., Conclusion: Serum analyte concentrations differ between Caucasian and Hispanic gravidas. Use of ethnic-specific medians reduces the disparity in SPR for trisomy 21 and neural tube defects., (Copyright © 2011 John Wiley & Sons, Ltd.)

Objective: Congenital lipoid adrenal hyperplasia is an autosomal recessive condition due to mutations in Steroidogenic Acute Regulatory Protein (StAR) associated with the inability to synthesize all adrenal and gonadal steroids, resulting in adrenal insufficiency and failure to develop male genitalia in affected 46,XY individuals. We used two independent methods of prenatal diagnosis for CLAH., Method: CLAH was diagnosed prenatally by measuring amniotic fluid estriol, adrenal, and gonadal hormone levels, and by mutation analysis for the c.201-202 delCT mutation in StAR., Results: Prenatal testing diagnosed one affected and three unaffected fetuses in two families at risk for CLAH., Conclusion: Prenatal testing for CLAH is effective, and targeted molecular genetic analysis should be considered in Palestinian families with a fetus with discordant 46,XY karyotype and female genitalia on ultrasound, and low maternal serum estriol.

Objective: Triple test with measured maternal serum alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol combination as a routine procedure for fetal Down's syndrome, trisomy 18 and neural tube defect screening has some intrinsic problems, such as precision. The aim of this study was to evaluate the effect of analytical variation of triple test on prenatal risk estimation., Method: Five different serum pools were prepared and triple test was performed seven times for within run and five times for between run precision determination., Result: Within run and between run, precision values of risk estimations by measuring the same sample for Triple test were calculated to be 7.9-21.4% and 14.1-31.0% for trisomy 21, 13.2-23.7% and 14.2-15.1% for trisomy 18, 47.2 and 42.0 % for neural tube defect, respectively., Conclusion: These results demonstrated that analytical variations have great impact on second trimester risk estimation procedures; therefore, triple test analyses should be carried out in laboratories using strict internal and external quality control programs. Moreover, triple test results should always be interpreted by considering analytical and biological variations.

Objective: To describe a method for deciding whether an individual's first-trimester Down syndrome screening test result justifies further testing in the second trimester., Methods: Statistical modelling was used to estimate the distribution of second-trimester marker profiles for a given first-trimester profile and hence the probability of a final positive result, using a 1 in 250 term cut-off. A multi-variate log Gaussian model was used with published parameters. Markers were maternal serum pregnancy-associated plasma protein-A and free beta-human chorionic gonadotrophin (hCG) at 10 weeks, nuchal translucency at 11 weeks, and second-trimester maternal serum alpha-fetoprotein, total hCG, unconjugated estriol and inhibin-A. To illustrate the method, the model was applied to a published series of 24 Down syndrome and 367 unaffected pregnancies., Results: Modelling predicts that for 63% Down syndrome and 0.4% unaffected pregnancies having first-trimester tests, there is a 50% or more probability of a final positive result. A step-wise sequential screening policy based on immediate prenatal diagnosis for those with high probability and second-trimester testing for the remainder would have a 90% detection rate and 1.7% false-positive rate. Modelling also predicts 8.0% Down syndrome and 89% unaffected pregnancies with probabilities below 3%. A contingent screening policy restricting second-trimester testing to those with 3-49% probabilities would have an 88% detection rate and 1.4% false-positive rate., Conclusion: Predicting the probability of a positive final result from the first-trimester marker profile has potential utility, either as a decision aide for individual women or as a formal part of screening policy in selecting a subset of women for second-trimester testing., (Copyright 2005 John Wiley & Sons, Ltd)

The ability of breast tumors to synthesize sex steroid hormones is well recognized and their local production is thought to play a role in breast cancer development and growth. The aim of this study was to estimate local intra-tumoral and circulating levels of Estrone (E1), Estrone Sulfate (E1S), Estradiol (E2), Estriol (E3), and Testosterone (T) in 33 pre- and postmenopausal women with primary breast cancer in comparison to 12 pre- and postmenopausal women with benign breast tumors. The mean levels of the studied sex hormones were higher in serum and tumor tissue of breast cancer women than those with benign breast tumors apart from Testosterone which showed a significant decrease in pre- and postmenopausal women with breast cancer (P<0.001for follicular phase, P<0.05 for luteal phase, and P<0.005 for postmenopausal). The levels of the five hormones were significantly higher intra-tumoral than in serum of both benign and malignant breast tumor women with E1S as the predominant estrogen. There was only a positive significant correlation between serum and tumor tissue levels of E1 (rs=0.52, P<0.05 for follicular; rs=0.63, P<0.05 for luteal and rs=0.58, P<0.05 for postmenopausal) and a significant correlation between serum and tumor tissue of T (rs=0.64, P<0.05 for follicular; rs=-0.51, P<0.05 for luteal and rs=-0.81, P<0.04 for postmenopausal).

In a study of amniotic fluid from 91 Down's syndrome cases and 240 controls, we have shown that the median values of four biochemical markers (AFP, total hCG, free beta hCG, and unconjugated oestriol) in the amniotic fluid of pregnancies affected by Down's syndrome on the whole reflect those observed in the maternal serum of affected cases. The median MOM for AFP was lower than average (0.56), as was that for unconjugated oestriol (0.55), whilst those for total hCG (1.82) and free beta hCG (2.10) were increased on average. The width of the distribution of marker levels in amniotic fluid is similar to that in serum for free beta hCG and total hCG but between 1.5 and 2 times wider for unconjugated oestriol and AFP. Analysis of data by fetal sex showed a significantly higher median MOM in female control cases compared with male controls for the analytes free beta hCG, total hCG, and unconjugated oestriol, but not for AFP. Amongst the Down's syndrome cases, this trend was not statistically significant and we cannot confirm a previous study which reported that elevated levels of amniotic fluid total and free beta hCG were associated only with female fetuses.

This study documents the screening performance, in practice, of a published protocol for interpreting second-trimester Down syndrome risk in twin pregnancies, using maternal serum biochemical markers. Within a cohort of 35,150 pregnancies, 410 twin pregnancies were identified. The rate of twinning was positively associated with maternal age. Of the 274 twin pregnancies known prior to screening, 15 (5.5 per cent) were classified as being screen-positive for Down syndrome. When maternal age and dating method were taken into account, the screen-positive rates in twin and singleton pregnancies did not differ significantly. Nine of the 14 screen-positive women with viable twin pregnancies chose amniocentesis [64 per cent, 95 per cent confidence interval (CI) 35-87]. No cases of Down syndrome were identified. Based on modelling, an estimated 73 per cent of monozygotic twin pregnancies and 43 per cent of dizygotic twin pregnancies with Down syndrome would be identified at a 5 per cent false-positive rate. The overall detection rate would be about 53 per cent. When laboratories offer multiple marker screening to women with twin pregnancies, the false-positive rate ought to be similar to that found in singleton pregnancies; the detection rate is, however, likely to be lower for dizygotic twins.

A new method is described for calculating maternal serum marker distribution parameters which will improve risk estimation when screening for Down's syndrome. The approach is to calculate parameters using data from the local screened population and data obtained by meta-analysis from all published studies. The local data are used to derive the variance and covariance in unaffected pregnancies. The meta-analysis is used for the mean level in Down's syndrome pregnancies together with the differences in variance and covariance between affected and unaffected pregnancies. Forty-four published studies were analysed. The mean level for Down's syndrome in multiples of the normal median was 0.73 for alpha-fetoprotein (AFP) in total of 1140 pregnancies, 0.73 for unconjugated oestriol (uE3) in 613, 2.02 for human chorionic gonadotropin (hCG) in 850, and 2.30 for free beta-hCG in 477. For all four markers, the variance in Down's syndrome was higher than in unaffected pregnancies; for AFP and uE3, the covariances were also higher in Down's syndrome, but for the other markers they were lower. The method was illustrated using data from 6387 pregnancies screened in Leeds.

Seventy-five pregnant women in the 38th to 41st weeks of gestation were given a single intravenous injection of 200 mg of dehydroepiandrosterone sulfate (DHAS). The changes in estriol, 17beta-estradiol and progesterone levels in the serum, the uterine cervix and the myometrium of the placenta-implanting site were then determined. Estriol levels remained unchanged both in serum and tissue, but the level of 17beta-estradiol increased sharply both in serum and tissue after four hours. The increases of 17beta-estradiol in the serum and the portio vaginalis of the same patient were well correlated (r = 0.79898), but the percentage of increase was much higher in the portio vaginalis than in the serum (p less than 0.001). Serum progesterone levels did not change initially, but always decreased within four or eight hours in cases in which labor had started or delivery was accomplished within 24 hours (p less than 0.01 at four hours). The total amount of collagenase was determined in ten subjects before and after the administration of DHAS. The total collagenase activity was elevated by an average of 152.3%. The peak of activity was accelerated from the fourth to the second day (p less than 0.001) of the culture. A probable mechanism of DHAS action in accelerating cervical ripening is presented.

As saliva is an easily accessible biological material, compared with 24-hour urine and blood, the salivary concentration of estriol was studied from the 30th to the 41st week of gestation in 268 samples from 124 normal pregnancies. At the same time, venous blood samples were drawn and analyzed for total and unconjugated estriol. The mean values for the concentration of total estriol in saliva in the 30th and 41st weeks were 2.8 and 7.2 nmol/l respectively. The salivary estriol concentration appears to increase in perfect conformity with its serum concentration in the course of gestation. If estriol in saliva also reflects low serum values and an impaired function of the feto-placental unit, analyses of the saliva may be applicable as a screening procedure in high-risk pregnancies.

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.