Improved estriol determination in a continuous flow system

Lever, Michael; Powell, Joanne; Peace, Simon

doi:10.1016/0006-2944(73)90024-0

Cited by 37 publications

(9 citation statements)

References 12 publications

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“…In the present study, the preg- For example, in the abnormal group of patients, labour was artificially induced in one third of the pregnancies, partly on the basis of low urine oestrogen values, and the mean gestational age at delivery was 37 weeks. However, when large numbers of assays are required, the method could not match the fully automated urine oestrogen methods with capacities for up to 60 analyses per hour (Lever et al 1973). Therefore, the emphasis in this study has been on comparing parallel plasma and urine values and the results have been correlated with various factors known to be associated with increased fetal risk.…”

Section: Discussionmentioning

confidence: 99%

Comparison Between Plasma and Urinary Oestrogen Measurements in Predicting Fetal Risk

Aickin

Smith

Brown

1974

Aust NZ J Obst Gynaeco

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A fluorimetric method for measuring total oestrogens in late pregnancy plasma is described and data on its precision, sensitivity, accuracy and specificity is presented. One worker can complete 24 analyses in a day.A total of 3 11 parallel estimations of total oestrogens in plasma and urine were performed in 119 initially normal pregnancies to define the normal ranges. A further 454 parallel estimations were performed in 166 patients with pregnancy abnormalities likely to be associated with increased fetal risk. The incidences of low oestrogen values in the initially normal group of patients were 21% for plasma and 17% for urine; the corresponding incidences in the abnormal group were 42% for plasma and 28% for urine. The correlation coefficient between the plasma and urine values was 0.71 in the 'normal' group and 0.58 in the abnormal group. These correlations were highly significant but did not allow one value to be calculated from the other with any accuracy. Throughout the study, plasma and urine oestrogen assays did not give synonymous information and it was concluded that it would be dangerous to establish plasma oestrogen measurements as a test of fetal welfare merely on the basis that urine measurements were useful.Plasma oestrogen assays gave the same assessment of fetal risk in 226 pregnancies and opposite assessments in 59. In the 59 pregnancies, the plasma values were correct in predicting fetal risk as often as the urine values. In the total 285 pregnancies, all indices of fetal risk except the passage of meconium during labour were increased when the plasma or urine values were low and the levels of significance of these correlations were the same for plasma as for urine. There was no evidence that one assay was superior to the other in any pregnancy complication including renal disease, or that changes in plasma values gave a more immediate indication of a rapidly deteriorating fetal environment than urine.It was concluded that plasma and urine oestrogen assays give equally valid information in the assessment of fetal risk, that they could well be used as complementary tests and that because of ease of collection and avoidance of time delay, plasma assays could replace urine assays as soon as rapid fully automated assay methods are developed for plasma comparable to those now available for urine.Measurement of urinary oestrogen excretion the fetus at risk as identified by low oestrogen is now a well established test for monitoring excretion. Urine as a test material for this purfetal welfare in utero. Maximum obstetric and pose has several inherent disadvantages. Sucpaediatric care can then be concentrated on cessful fetal monitoring depends on rapid 60

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Section: Discussionmentioning

confidence: 99%

Comparison Between Plasma and Urinary Oestrogen Measurements in Predicting Fetal Risk

Aickin

Smith

Brown

1974

Aust NZ J Obst Gynaeco

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“…The patients had an average of four assays of each biochemical test performed at various gestations, thus providing sufficient samples for statistical analysis for each week from 28 weeks to delivery. The assays performed were plasma unconjugated oestriol (Evans 1979), plasma progesterone (Duff et al 1980), plasma human placental lactogen (hPL, radioimmunoassay kit, Radiochemical Centre, Amersham, Bucks., UK), serum cystyl aminopeptidase (CAS, Mancini et al 1965 with Behringwerke AG standards and antisera preparations) and urine oestriol (Lever et al 1973). Normal values and ranges from the study data are shown in Table 1.…”

Section: Methodsmentioning

confidence: 99%

Antenatal biochemical screening to predict low birthweight infants

Aickin

Duff

Evans

et al. 1983

BJOG

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Summary. Urine and plasma oestriol, plasma progesterone, human placental lactogen, α‐glycoprotein and serum cystyl aminopeptidase were measured at intervals during 608 pregnancies. The predictive accuracy of low values for identification of pregnancies with low birthweight outcomes was assessed for each test at various gestations. Data were analysed to obtain 10th–90th centile values for each test from 28 weeks to delivery. Groups with values under different centile levels were compared: those under the lower centiles had higher proportions but smaller absolute numbers of low birthweight infants than those under higher centiles. No test was superior to the others at all centiles and gestations. Biochemical screening of pregnant populations to identify high‐risk groups for intensive fetal monitoring has limited potential. If screening is used, the definition of high‐risk groups is best achieved by practical rather than statistical criteria. If monitoring facilities are available and well accepted by patients then higher centile‘cut‐offs’to define fetal risk may be used than when they are not. Combining any pair of tests with values below the 10th centile did not reduce false positive and negative predictions any more than could be achieved by movement of centiles up or down for a single test.

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“…The between-assay precision was 12%, and the sensitivity was 0.3 nmol/l. Urinary oestrogens were measured by a continuous flow system with a fluorimetric end-point based on the technique described by Lever et al (1973).…”

Section: Methodsmentioning

confidence: 99%

Antenatal detection of placental steroid sulphatase deficiency: use of a dehydroepiandrosterone sulphate loading test

Oakey

1984

BJOG

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summary Dehydroepiandrosterone sulphate (50 mg) was given intravenously to 15 women in the third trimester of pregnancy in which urinary oestrogen excretion was subnormal (<32 μmol/24 h) without recognizable clinical or therapeutic cause. In six patients, this procedure was followed by a marked increase in plasma oestradiol concentrations [mean (SD), nmol/1] before treatment: 44 (13) and 30 min after injection: 279 (31). After delivery, the placentas from all these patients showed steroid sulphatase activity in vitro (>450 units). In the other nine patients, all of whom subsequently showed negligible placental steroid sulphatase activity in vitro (< 10 units), mean plasma oestradiol concentrations increased only from 18 (9) to 26 (11) nmol/1. Changes in plasma oestradiol concentrations in late pregnancy after injection of dehydroepiandrosterone sulphate therefore readily permit identification of those patients in whom a placental enzyme deficiency is the cause of the subnormal oestrogen production. The defect was identified as steroid sulphatase deficiency by an in‐vitro test of placental tissue after delivery.

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Improved estriol determination in a continuous flow system

Cited by 37 publications

References 12 publications

Comparison Between Plasma and Urinary Oestrogen Measurements in Predicting Fetal Risk

Comparison Between Plasma and Urinary Oestrogen Measurements in Predicting Fetal Risk

Antenatal biochemical screening to predict low birthweight infants

Antenatal detection of placental steroid sulphatase deficiency: use of a dehydroepiandrosterone sulphate loading test

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