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Biomedical subjects

F Delange

Publications and source records attributed to F Delange.

At least 19 recordsLinked to original sources
PubMed1992

Maternal and neonatal thyroid function at birth in an area of marginally low iodine intake.

Thyroid function was evaluated in cord serum of healthy full-term newborns and compared to that of mothers immediately after parturition. The study was carried out in an area without overt iodine deficiency, but with a marginal iodine supply (less than 100 micrograms/day in 80% of women). The aim of the study was to delineate the interrelationships between the thyroid statuses of mother and child at birth. Maternal thyroid function was characterized at delivery by relative hypothyroxinemia; increased T3/T4 ratios, indicating preferential T3 secretion; slightly increased TSH levels within the normal range in 97% of women; increased serum thyroglobulin (TG) values, which were above normal in 60% of women; and also goiter formation in almost 10% of women. The findings indicated glandular stimulation and confirmed our earlier reports that pregnancy constitutes a stress for the maternal thyroid economy, enhanced by the limited availability of iodine in the diet. By contrast, newborns showed a strikingly distinct pattern: there was no relative hypothyroxinemia and free T4 levels were significantly higher than in the respective mothers (19.4 vs. 14.7 pmol/L; P less than 0.001). In spite of these differences, however, mean neonatal TSH and TG levels were significantly higher than maternal values, respectively 6.0 vs. 1.9 mU/L for TSH (P less than 0.001) and 70 vs. 40 micrograms/L for TG (P less than 0.001). Furthermore, neonatal TG and TSH levels increased in parallel and were highly correlated with maternal data, suggesting a regulatory link between both thyroid economies. The results suggested that the common regulatory link is the limited availability of the iodine supply. In conclusion, the present study demonstrates that even in conditions with a marginally low iodine intake, pregnancy constitutes a stimulus for both the maternal and newborn thyroids. Changes in both groups are associated and the abnormalities in TSH and TG are amplified in the newborns. The TSH and TG alterations at birth in full-term healthy newborns, associated with similar alterations in maternal thyroid function, provide evidence for a common stimulatory factor, relative iodine deficiency. The data emphasize the hypersensitivity of neonatal thyroid function to marginal iodine deficiency and point to the need to increase the iodine supply in groups at risk, such as women during pregnancy, and also newborns in the perinatal period.

Cohort Studies↗
PubMed1991

Determination of thyroid volume by ultrasound from the neonatal period to late adolescence.

The volume of the thyroid gland was determined by ultrasonography in 256 euthyroid subjects aged 0-20 years in Brussels, an area with borderline iodine intake (median urinary iodine: 6.8 micrograms/dl). The volume of each lobe was calculated separately using the formula of an ovoid (Depth x Length x Width x pi/6). The total thyroid volume was obtained by summation of the volume of both lobes. In neonates, mean volume (SD) was 0.84 (0.38) ml and the distribution was asymmetric, skewed towards elevated values (median: 0.76 ml); the volume was best correlated with body surface area (P less than 0.01). Thyroid volume significantly increased (P less than 0.001) until the age of 8 without being influenced by sex and thereafter varied widely: it increased from 2.7 (0.8) ml in prepubertal subjects aged 8-11 years to 11.6 (4.4) ml in late pubertal aged greater than 17 years. This increase was significantly correlated not only with chronological age but also with pubertal stage and seemed to happen early, with the onset of the first clinical signs of puberty. At all ages, the volume of the right lobe was slightly higher than the left lobe but the difference was not significant.

Adolescent↗
PubMed1991

Radionuclide imaging in primary permanent congenital hypothyroidism.

Thyroid scintigraphy was performed in 69 consecutive infants with permanent primary congenital hypothyroidism (CH) detected by systematic neonatal thyroid screening using a rectilinear scanner or a gamma camera 15 minutes after the intravenous injection of 250 microCi Tc-99m sodium pertechnetate, immediately after the infants were fed. Immobilization of the infant in a supine position with the neck in hyperextension was achieved by a vacuum cushion without any sedation. Thyroid scintigraphy showed thyroid ectopia in 43 of the 69 CH infants, thyroid agenesis in 19, and goiter in the last 7 infants, respectively. The images were easily interpretable in all cases, even in very small ectopic glands in the lingual area, as there was no interference with extra-thyroidal uptake of the tracer, especially by the salivary glands. Our experience indicates that thyroid scintigraphy in the CH newborns can be performed immediately at the time of diagnosis of CH without technical difficulties. As thyroid scintigraphy is the only procedure allowing the distinction between thyroid agenesis and ectopia, and as the neurointellectual prognosis might be lower in the former than in the latter situation, thyroid scintigraphy in CH newborns contributes not only to the diagnosis but also the prognosis of the disorder.

Choristoma↗
PubMed1991

Smoking during pregnancy: a significant cause of neonatal thyroid enlargement.

The influence of maternal smoking during pregnancy on the function and the echographic volume of the neonatal thyroid gland was examined in an area of borderline iodine intake (median maternal urinary iodine: 315 range 79-1558 nmol/l). There was a positive correlation (P less than 0.001) between cord serum thiocyanate (SCN) concentrations used as an index of maternal smoking and the maternal smoking habits. The thyroid volume/birthweight ratio increased significantly as a function of SCN values (P less than 0.005): this increase was secondary to a decrease in birthweight as well as to an increase in thyroid volume. There was also a positive correlation between cord serum thyroglobulin (Tg) and SCN levels (P = 0.001). Serum thyroid-stimulating hormone (TSH) and free thyroxine (FT4) values remained within the normal range for age in all newborn infants and were not significantly correlated with SCN values. These results show that smoking during pregnancy in areas with borderline iodine intake may be a significant cause of thyroid enlargement in the newborn.

Belgium↗
PubMed1991

Pregnancy in patients with mild thyroid abnormalities: maternal and neonatal repercussions.

A prospective study was undertaken during pregnancy in 120 euthyroid women presenting with mild thyroid abnormalities (TA): 11 with a past history of thyroid disorder, 44 with goiter, 20 with nodules, and 45 with thyroid autoantibodies. The aims of the study were to assess whether the pattern of thyroid alterations during gestation was different in women with TA compared to that in healthy control pregnant subjects and to evaluate possible obstetrical and neonatal repercussions. The overall prevalence of underlying subtle thyroid abnormalities in the cohort was 17%, probably as the result of the environmental moderately low iodine intake. Despite the intrinsic heterogeneity of the four groups of women with TA, the adaptation of the thyroid to the stress of pregnancy was different from that of the control subjects. Noteworthy were 1) the marked elevation of serum thyroglobulin in women with past history of thyroid disorder, goiter and thyroid nodules; 2) the increase in goiter size in a third of the goitrous women, associated with biochemical evidence of functional stimulation of the gland; 3) the indirect evidence of partial thyroidal autonomy in goitrous patients; and 4) the increase in the number and size of thyroid nodules during gestation. Taken together, the data indicated that pregnancy was associated with a greater thyroidal risk in patients with TA compared to healthy subjects. In relation to thyroid autoimmunity, most patients remained euthyroid during gestation, but in a few cases, TSH was elevated at delivery, suggesting diminished thyroidal reserve. Also, 40% of newborns from mothers with thyroid autoimmunity had elevated thyroid peroxidase antibody titers at birth, and there was a highly significant correlation between maternal and neonatal thyroid peroxidase antibody titers. Finally, thyroid autoimmunity was clearly associated with an increased risk of spontaneous abortion (13.3 vs. 3.3%; P less than 0.001). Thyroid function in newborns from mothers with TA was normal and not different from that in controls; similarly, obstetrical features were similar in patients with TA and control subjects. In conclusion, pregnancy is associated with a greater thyroidal risk in women with TA, thereby emphasizing a potential link between pregnancy and thyroid disorders. It is recommended that patients with known, even subtle, thyroid abnormalities be closely monitored during pregnancy, in particular those with a goiter, nodules, or thyroid autoimmunity, especially in areas with a moderately low iodine intake, where the prevalence of mild thyroid disturbances is high.

Adult↗
PubMed1990

Contribution of thyroid ultrasound and serum calcitonin to the diagnosis of congenital hypothyroidism.

UNLABELLED: To elucidate the role of thyroid ultrasound (TU) in the diagnosis of congenital hypothyroidism (CH), we compared 1) TU and thyroid scintigraphy (TS) in 6 CH newborns and 2) TU results in the 6 CH newborns, in 8 newborns with "false positive" results at screening, in 13 CH children aged 2 mo to 12 yr treated since the neonatal period and in 235 controls aged 0-12 yr. RESULTS: 1) In all 6 CH newborns with no thyroid uptake at TS, TU evidenced small posterior hyperechogenic masses in the thyroid area [Vol: 322 +/- 180 (SD) mm3]; 2) In all normal controls and in the 8 "false positive" cases at screening TU showed normal thyroid structures. The thyroid volume was 831 +/- 383 mm3 in normal newborns and progressively increased with age. In the older CH children, TU also demonstrated the hyperechogenic masses, but their volume barely increased with age: as a consequence, the difference between the volume of the masses in CH patients and the thyroid tissue in controls, already significant in newborns (p less than 0.01), markedly increased with age. The exact nature of these masses is unknown; they could represent poorly vascularized ultimobranchial remnants containing the calcitonin - secreting cells: this hypothesis is supported by our finding that serum concentrations of calcitonin (measured by a sensitive extraction method) (mean +/- SD, pg/ml) were lower in the CH patients (2.9 +/- 1.5) than in controls (13.0 +/- 6.9; p less than 0.001) at birth. In conclusion, in all cases of CH, TU showed abnormal structures in the thyroid area. TU and TS provide complementary information in the diagnosis of CH, and TU should be routinely performed in all newborns suspected of CH to avoid unnecessary use of TS in unaffected infants.

Calcitonin↗
PubMed1990

[Disorders due to iodine deficiency].

1. An insufficient dietary supply of iodine results in the development of a variety of disorders of thyroid function and development of the fetus and young infants, grouped under the general heading of Iodine Deficiency Disorders, IDD. Endemic goiter constitutes the most spectacular disorder from the clinical and epidemiological point of view. However, the most serious consequence of iodine deficiency is the impact on neuro-intellectual development at a population level, varying from endemic mental retardation to the complete picture of endemic cretinism. 2. Considering that mental retardation due to iodine deficiency represents the longterm consequence of hypothyroidism occurring during the perinatal period, it is presently recognized that the target groups to the effects of iodine deficiency at a population level are, by order of priority, the fetus, the newborn, the pregnant woman, the child and, finally, the adult. 3. The newborn is more susceptible than the adult to the effects of iodine deficiency. Consequently, systematic screening for congenital hypothyroidism in endemic areas is a particularly sensitive index for detecting the presence and action of goitrogens in the environment and for monitoring the effects of programs of iodine prophylaxis. 4. IDD are particularly prevalent in developing countries. However, large areas or even countries in Europe are still obviously iodine deficient. For example, the iodine intake in adults in Belgium is 50 to 70 micrograms/day which is lower than the recommended dietary allowance for iodine (at least 100 micrograms/day). 5. IDD should be corrected on a world scale, including in Europe. Special attention should be devoted to the protection of mother and child. Within this framework, the iodine content of formula milk should be increased in Europe. 6. Finally, correction of iodine deficiency in Europe would decrease the avidity of the thyroid for iodide and, consequently, would constitute the most efficient preventive measure in case of nuclear fallout.

Adult↗
PubMed1989

Effect of vaginal douching with povidone-iodine during early pregnancy on the iodine supply to mother and fetus.

Vaginal douching with polyvinylpyrrolidone iodine (PVP-I) during pregnancy results in maternal iodine overload and increases the iodine content of amniotic fluid. We evaluated the possible effects of this therapy on the thyroid of the fetus by investigating 62 women with a mean duration of amenorrhea of 20 weeks who solicited controlled abortion. Nineteen of them douched daily with PVP-I for 7 consecutive days before abortion (treated group). The other 43 women were not treated (control group). In both groups the iodine content was determined in the fetal thyroid and in amniotic fluid and maternal urine at the time of abortion. In addition, in the treated group the concentrations of iodine were also determined in amniotic fluid and urine before therapy and in urine after 4 days of therapy. There were no differences in the concentrations of iodine in urine and amniotic fluid in the control group and in the treated group before therapy. In the treated group urinary iodine increased from 6.1 +/- (SEM) 0.8 micrograms/dl before therapy to 91 +/- 20 micrograms/dl after 4 days and to 153 +/- 60 micrograms/dl after 7 days of therapy (p less than 0.001). In parallel, iodine in amniotic fluid increased from 1.2 +/- 0.2 micrograms/dl before therapy to 3.7 +/- 1.3 micrograms/dl after 7 days (p less than 0.05). In both groups the iodine content of the fetal thyroid increased with gestational age. However, it increased more rapidly in the treated group (from 1 to 7.7 micrograms) than in the control group (from 1 to 2.5 micrograms), p less than 0.05.(ABSTRACT TRUNCATED AT 250 WORDS)

Abortion, Induced↗
PubMed1989

Iodine deficiency disorders in Europe.

Recent data on iodine excretion in the urine of adults, adolescents and newborns and on the iodine content of breast milk indicate a high prevalence of iodine deficiency (moderate in many cases and severe in a few) in many European countries. These cases may manifest as subclinical hypothyroidism in neonates and as goitre in adolescents and adults. Lack of iodine causes not only goitre, but also mental deficiency, hearing loss and other neurological impairments, and short stature due to thyroid insufficiency during fetal development and childhood. Although iodinated salt is available theoretically in most countries where it is needed, its quality and share of the market are often unsatisfactory. In many countries where only household salt is iodinated the iodine content has been set too low owing to an overestimation of household salt consumption. Governments are therefore urged to pass legislation and provide means for efficient iodination of salt wherever this is necessary.

Adolescent↗
PubMed1988

Neonatal hypothyroidism: recent developments.

This chapter summarizes recent developments in the field of sporadic congenital hypothyroidism (CH) and transient neonatal hypothyroidism detected by systematic neonatal thyroid screening. The incidence of CH detected by screening is about 1 in 4000 births in North America, Europe and Australia; it is lower (1 in 7000) in Japan. The aetiology remains unknown; genetic and environmental factors are possibly involved. The role of autoimmunity has recently been studied extensively. Antithyroglobulin (ATA) and antimicrosomal antibodies are not involved; the possible role of thyroid growth blocking antibodies (TGBAb) of maternal origin remains controversial. Evaluation of clinical signs, bone maturation, serum T4 and the position and size of the thyroid by scintigraphy at the time of diagnosis in CH infants are important because these variables are related to the final psychoneuro-intellectual prognosis, irrespective of the adequacy of therapy. Thyroid echography always distinguishes a normal thyroid in the neonate but cannot define precisely the type of thyroid dysgenesis, if present (e.g. ectopic, athyreosis). The determination of serum Tg contributes to the diagnosis but its specificity and sensitivity are insufficient to replace thyroid scintigraphy. Therapy by LT4, at an initial dose of 25-50 micrograms/day in full-term infants, is universally recommended. The objective of therapy is to reach as soon as possible and to maintain serum concentrations of total and free T4 at the upper limits of normal for age. Serum TSH should decrease as rapidly as possible below 20 microU/ml and then remain within the normal range. Persistent hyperthyrotropinaemia in spite of normal serum T4 has to be avoided as it could represent poor compliance and/or insufficient therapy. Programmes of 10 to 14 years of follow-up of CH infants have now shown that the neuropsychointellectual prognosis of CH is excellent in all cases when therapy and psychosocial environment are adequate. Although still within the normal range, IQ is somewhat lower in spite of appropriate therapy in cases of severe prenatal hypothyroidism and some transient and correctable neurological signs occasionally occur. In Western countries transient neonatal hypothyroidism is usually due to iodine deficiency or iodine excess; the newborn infant is hypersensitive to the antithyroid action of an extraphysiological supply of iodine. TSH binding inhibitor immunoglobulins (TBII) of maternal origin occasionally cause transient neonatal hypothyroidism. In developing countries with severe iodine deficiency and endemic goitre, the incidence of thyroid failure in the newborn can be as high as 1 in 10.(ABSTRACT TRUNCATED AT 400 WORDS)

Congenital Hypothyroidism↗
PubMed1988

Increased recall rate at screening for congenital hypothyroidism in breast fed infants born to iodine overloaded mothers.

Skin disinfection with povidine-iodine (PVP-I) is widely used in obstetrics. We evaluated the influence of PVP-I in mothers at delivery on the serum thyroid stimulating hormone concentrations of their infants at the time of screening for congenital hypothyroidism. The study covered 4745 infants who were either breast fed (3659, 77%) or bottle fed (1086, 23%); 3086 (65%) of them were born to mothers with no iodine overload (controls) and 1659 (35%) to mothers with iodine overload. Compared with the control group, the breast and bottle fed infants born to mothers with iodide overload had a shift of neonatal thyroid stimulating hormone concentration towards high values. The shift was maximal in the breast fed infants with a 25 to 30 fold increase in the recall rate at screening for congenital hypothyroidism (serum thyroid stimulating hormone greater than 50 mU/l) while in the bottle fed infants, the recall rate was barely modified. In conclusion, the use of PVP-I in mothers at delivery induces a transient impairment of thyroid function in their infants, especially if breast fed. This situation is detrimental to screening for congenital hypothyroidism. Consequently PVP-I is not recommended in obstetrics.

Breast Feeding↗
PubMed1988

[The role of goitrogenic factors distinct from iodine deficiency in the etiology of goiter].

The main cause of endemic and sporadic goiter is a deficiency in the dietary supply of iodine. However, iodine deficiency is not the only cause of goiter. This paper reviews present knowledge on the role of naturally occurring goitrogens in the etiology of goiter. Vegetables from the Cruciferae family, chronic consumption of poorly detoxified cassava containing large amounts of cyanogenic glucosides, flavonoids, humic substances originating from the organic residues in the soil are clearly involved in the etiology of endemic goiter. Iodine excess, especially in the newborn infants, lithium and thiocyanate overload resulting from smoking habits can be responsible for the development of goiter in non endemic areas.

Goiter↗
PubMed1987

Cold thyroid nodules in childhood: is surgery always necessary?

In children who present with a cold thyroid nodule the current recommendation is that surgery immediately be performed in view of the high probability of thyroid cancer. Because the incidence of thyroid cancer in children may be decreasing and because extensive experience has been gained in adults with thyroid echography and fine-needle aspiration cytology, we evaluated three consecutive children with cold thyroid nodules by means of these non-surgical techniques. The diagnoses were: thyroid cancer in one patient, thyroid abscess in one and haemorrhagic cyst of the thyroid in one. In the latter two patients, fine-needle aspiration was both diagnostic and therapeutic. We conclude that thyroid echography and fine-needle aspiration of thyroid nodules deserve more extensive evaluation in the paediatric age group.

Adolescent↗