The incidence and significance of low oestriol excretion in an obstetric population

Nutritional anaemias

Nutritional anaemia is recognized as a major public health problem throughout the world, especially in developing countries. Infants, young children, menstruating women and, in particular, pregnant women are most frequently affected. Sufficient evidence suggests that iron deficiency is the most common cause of nutritional anaemia in the world. Folate deficiency is considered as the second most common cause. In this chapter we discuss the factors determining nutritional inadequacy in iron and folate requirements versus iron and folate intake, particularly in different age/sex categories; the amounts of iron and folate involved in daily exchange and the role of the diet and physiological and pathological variations in losses and requirements are reviewed. The consequences in terms of health of iron and folate deficiencies and methods for assessing iron and folate status of populations are also presented.

Routine testing and prophylaxis

Routine testing and prophylaxis is considered in terms of haematological disorders, biochemical testing, hormonal testing, screening for gestational diabetes and nutritional deficiencies. Within these headings the place of routine supplementation of pregnant women with iron, vitamins, trace elements and an increased protein/calorie intake is discussed. Screening for haemoglobinopathies, irregular blood group antibodies and gestational diabetes is dealt with in detail. The place for routine prophylaxis with anti-D is considered. Biochemical and hormonal testing is covered with particular reference to the use of biochemical and hormonal assays as placental function tests and their use in assessing fetal well-being. In this respect the use of biochemical and hormonal tests to screen a pregnant population for intrauterine growth retardation is also discussed.

Pregnancy outcome in women perceiving decreased fetal movement

Out of 1914 women who had been instructed to count fetal movements (FMs) throughout the third trimester of pregnancy, 158 consulted the delivery ward staff about decreased FMs; they constituted the study group. Each woman who reported decreased FMs was examined by cardiotocography, analysis of plasma estriol and objective recording of FMs. Appropriate clinical management was decided on by the obstetrician in charge. In 133 (84%) of the 158 women, the results of the fetal examinations proved normal and no intervention was undertaken; in one of these cases the fetus died within 48 h. In two previously uncomplicated pregnancies the maternally perceived decrease in FMs coincided with seriously and persistently abnormal fetal heart rate test results. In both cases caesarean section was carried out within 24 h; the babies had Apgar scores less than or equal to 6 at 1 and 5 min but subsequently developed normally. Babies with congenital malformations (p = 0.001) and small-for-gestational age babies (p = 0.040) were significantly more common among consulters than non-consulters. The fetuses of women who report decreased FMs constitute a risk group and should be carefully monitored; if abnormalities are disclosed there is a potential for improving the fetal outcome by taking appropriate action.

Is serum free estriol measurement essential in the management of hypertensive disorders during pregnancy?

A prospective study of antepartum fetal evaluation of 306 randomized hypertensive pregnancies was carried out. One hundred and fifty-four patients (group 1) were managed in accordance with a protocol (protocol A) which included non-stress test (NST), oxytocin challenge test (OCT), serum unconjugated (free) estriol measurements (E3), and ultrasound measurement of the fetal head-to-abdomen circumference ratio (H/A c.r.). A second group (group 2), composed of 152 patients, was managed using another protocol (protocol B) which included the NST, OCT and ultrasound measurement of the fetal head-to-abdomen circumference ratio (H/A). We found a good correlation between the serial normal tests and the outcome of pregnancies. We obtained good results in patients with abnormal NST-OCT and meconium-stained amniotic fluid and in patients with repeated abnormal NST-OCT with clear amniotic fluid due to active management by early deliveries ignoring fetal lung maturity. This management increased the rate of cesarean section and prematurity. There was a low correlation between patients with abnormal serum free estriol as the only antepartum pathological test and the appearance of intrapartum fetal distress, low birth weight and perinatal morbidity and mortality. The contribution of serum free estriol (E3) measurements in such patients was only of value in cases of intra-uterine fetal growth retardation, but its prediction rate was less than that of ultrasound measurement of head-to-abdomen circumference ratio. Our results indicate that hypertensive pregnancy management without serum free estriol measurement may be valuable and safe.

Liquid chromatography with fluorometric detection of unconjugated estriol in serum of pregnant women

We describe a fluorometric liquid chromatographic assay for the measurement of unconjugated estriol in the serum of pregnant women. Estriol is extracted into methylene chloride/propanol-2 from serum by use of a Clin-Elut extraction column, the extract evaporated, and the residue redissolved in mobile phase. An aliquot is injected onto the liquid chromatograph and the estriol is separated on a reversed-phase octyl column with a mobile phase consisting of acetonitrile/phosphate buffer (23:77, v/v). The effluent is monitored by fluorescence detection. The proposed method offers good reproducibility (CV less than 7%), sensitivity (less than 0.5 micrograms/l), and accuracy. Of many drugs and steroids tested, only 16,17-epiestriol interferes with the estriol analysis.

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.

Paediatric follow up of pregnancies complicated by subnormal oestriol excretion. Interim report

In 92 pregnant women with low urinary oestriol excretion after 30 weeks' gestation, there was a higher incidence of fetal distress, premature delivery and induced labour, while resuscitation of the infant at birth was required more often than in controls. The birth weights, head circumference, and body lengths of the infants were significantly lower than those of the controls. In the 26 cases where maternal oestriol levels were persistently low, three were associated with placental sulphatase deficiency, and three infants died postnatally. Four infants had evidence of neurological defects on follow up, as did four infants in the control group. The low head circumferences, weight, and length were still present at two years of age. It is concluded that, although low oestriol excretion during pregnancy is associated with increased risk to the fetus, it is not associated per se with permanent neurological damage, provided the infant is born alive, and is congenitally normal. However, many infants remain smaller than average, at least for the first years of life.

Trial of intravenous therapy in women with low urinary estriol excretion

Estriol excretion in pregnancy is favourably improved following administration of 25% dextrose to patients with persistently low estriol excretion. A double-blind controlled trial was undertaken in 60 patients to assess the efficacy of other regimens of infusion therapy with Hartmann's solution, aminofusin, 10% dextrose, or ritodrine in Hartmann's solution. Estriol excretion rose above the lower limit of normal in 69% of the patients treated. There was no significant difference in success rates between the four solutions studied when subjected to analyses of variance and covariance. Fetal and placental weights were directly related to estriol excretion. Influences of the various therapeutic regimens on metabolic acidosis have been considered and possible reasons for therapeutic success discussed.

The association between abnormal glucose tolerance (hyperglycemia and hypoglycemia) and estriol excretion in pregnancy

In 2,000 consecutive patients having glucose tolerance tests in pregnancy hyperglycemia (greater than or equal to ninety-fifth percentile) was associated with increased placental weight (p less than 0.01) but not with increased fetal birth weight. Patients with hypoglycemia (less than or equal to fifth percentile) were more likely to have small-for-dates babies (p less than 0.01). Perinatal death was related to maternal glucose tolerance, being reduced from 1.3% in the total series to 0.6% when normoglycemia was present (p less than 0.05); it was significantly increased in the presence of maternal hyperglycemia (p less than 0.001) and hypoglycemia (p less than 0.01). A combination of abnormal glucose tolerance and subnormal estriol excretion detected pregnancies with significantly higher incidences of fetal and placental growth retardation, major fetal malformations, and perinatal deaths. Moreover, the combination of normoglycemia and normal estriol excretion (62.3% of patients) was associated with a very favorable pregnancy outcome (0.4% perinatal death rate). Hypoglycemia was at least as significant as hyperglycemia in terms of unfavorable pregnancy outcome, especially when associated with subnormal estriol excretion.

The influence of abnormal glucose tolerance (hyperglycaemia and hypoglycaemia) on pregnancy outcome when oestriol excretion is subnormal

Subnormal urinary oestriol excretion was present in 611 (13.9 per cent) of 4403 consecutive patients in whom a glucose tolerance test had been performed and urinary oestriol excretion measured during the third trimester of pregnancy. Hypoglycaemia (less than 5th centile) had a significant association with subnormal oestriol excretion. The perinatal mortality rate was significantly higher in the presence of abnormal glucose tolerance when oestriol excretion was low. Normoglycaemia was associated with a perinatal mortality rate of 1.7 per cent when oestriol excretion was persistently low, whereas in the presence of hyperglycaemia (greater than 95th centile) the perinatal mortality rate was 12.5 per cent (P less than 0.01) and when there was hypoglycaemia the rate was 14.8 per cent (P less than 0.001). Small-fordates babies occurred in 46.3 per cent of pregnancies complicated by hypoglycaemia and persistently subnormal urinary oestriol excretion. The advantage of routine urinary oestriol assay and glucose tolerance testing in pregnancy is emphasized.