Thyroid dysfunction is a common occurrence in pregnancy and affects both maternal and fetal outcomes. There are limited data on prevalence of hypothyroidism during pregnancy from India. Therefore, this study was designed to evaluate the prevalence of thyroid dysfunction especially hypothyroidism during first trimester in a large public hospital in North India.
Materials and Methods:
All the consecutive first trimester pregnant women attending Lok Nayak and Kasturba Hospitals were enrolled in the study after institutional ethics approval and consent from the study subjects. The pregnant women with diagnosed thyroid disease and on thyroid medications were excluded from the study. Morning samples of study participants were analyzed for thyroid hormone profile which included free T3, free T4, TSH, and TPO Ab. In addition, all study participants were tested for CBC, LFT, KFT, and lipid profile.
A total of 1000 women were enrolled for this prospective observational study. The mean (SD) age of study subjects was 25.6 (11.1) years, and mean (SD) gestational age was 10.3 (3.4) weeks. One hundred and forty-three (14.3%) subjects had TSH values more than 4.5 mIU/L above the cutoff used for definition of hypothyroidism. Out of these, 135 had normal free T4 and therefore labeled as subclinical hypothyroidism and 7 had low free T4 suggestive of overt hypothyroidism. TPO Ab was positive in 68 (6.82%) of total, 25 (18.5%) of subclinical and 5 (71%) of overt hypothyroid patients.
Hypothyroidism, especially subclinical, is common in North Indian women during first trimester. Further countrywide studies are needed to evaluate the prevalence and etiology of hypothyroidism to prevent maternal and fetal adverse effects of hypothyroidism in India.
Pregnancy; hypothyroidism; subclinical hypothyroidism; autoimmunity and India
Thyroid antibody positivity during pregnancy has been associated with adverse outcomes including miscarriage and preterm delivery. The aim of the study is to evaluate the obstetric outcome in pregnant women with recurrent miscarriage and their response to levothyroxine (l-T4) therapy.
Study design and methods
All pregnant and non-pregnant women between 21 and 35 years of age with a history of two or more consecutive miscarriages were included in the study. A third group comprising 100 pregnant women without a history of miscarriage were taken as healthy controls. Thyroid autoimmunity, prevalence of subclinical hypothyroidism and maternal and foetal complications were analysed in all the groups with appropriate statistical methods.
The mean age of the patients included in the study was 27.0±3.1 years. Of 100 pregnant patients with previous recurrent miscarriage, thyroid autoimmunity (thyroid peroxidase antibody (TPOAb+) >34 U/ml) was found in 31% of the cases. The incidence of subclinical hypothyroidism was higher in TPOAb+ group than in TPOAb− group (52 vs 16%; P=0.0002). There was no difference in the prevalence of miscarriage or obstetric outcomes between recurrent miscarriage and healthy pregnant women group irrespective of TPO status.
The prevalence of thyroid autoimmunity was higher in pregnant women with a history of recurrent abortion compared with healthy pregnant control population. Following l-T4 treatment, there was no difference in prevalence of miscarriage between hypothyroid and euthyroid individuals in TPOAb+ women.
recurrent miscarriage; thyroid peroxidase; hypothyroidism; preterm birth
Purpose of the Review:
Thyroid disturbances are common in women during their reproductive years. Thyroid dysfunction interferes with human reproductive physiology, reduces the likelihood of pregnancy and adversely affects pregnancy outcome, thus becoming relevant in the algorithm of reproductive dysfunction. This review highlights the gap in knowledge regarding the contribution of thyroid dysfunction in reproduction.
Following implantation, the maintenance of the pregnancy is dependent on a multitude of endocrinological events that will eventually aid in the successful growth and development of the fetus. It is estimated that approximately 8-12% of all pregnancy losses are the result of endocrine factors. Autoimmune thyroid disease is present in around 4% of young females and up to 15% are at risk because they are thyroid antibody-positive. There is a strong relationship between thyroid immunity on one hand and infertility, miscarriage, and thyroid disturbances in pregnancy and postpartum, on the other hand. Even minimal hypothyroidism can increase rates of miscarriage and fetal death and may also have adverse effects on later cognitive development of the offspring. Hyperthyroidism during pregnancy may also have adverse consequences.
Pregnant women with subclinical hypothyroidism or thyroid antibodies have an increased risk of complications, especially pre-eclampsia, perinatal mortality, and miscarriage. Universal screening for thyroid hormone abnormalities is not routinely recommended at present, but thyroid function must be examined in female with fetal loss or menstrual disturbances. Practitioners providing health care for women should be alert to thyroid disorders as an underlying etiology for recurrent pregnancy loss.
Recurrent pregnancy; thyroid autoimmunity; thyroid disorder
Thyroid function changes during pregnancy and maternal thyroid dysfunction have been associated with adverse outcomes. Our aim was to evaluate thyroid hormones levels in pregnant women resident in Aragon, Spain.
Samples for 1198 pregnant women with no apparent thyroid disorders were analyzed, using paramagnetic microparticle and chemiluminescent detection technologies, in order to determine levels of thyroid stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), thyroid peroxidase antibodies (TPO-Ab), and thyroglobulin antibodies (Tg-Ab). Of the women in our sample, 85.22% had normal values for TPO-Ab and Tg-Ab and 14.77% had results revealing the presence of autoimmune diseases of the thyroid. The thyroid hormone reference values obtained according to gestational age (in brackets) were as follows: for free T3, values were 3.38 ± 0.52 pg/mL (<11 weeks), 3.45 ± 0.54 pg/mL (11-20 weeks), 3.32 ± 0.43 pg/mL (21-30 weeks), 3.21 ± 0.53 pg/mL (31-36 weeks), and 3.23 ± 0.41 pg/mL (>36 weeks); for free T4, values were 1.10 ± 0.14 ng/dL (<10 weeks), 1.04 ± 0.14 ng/dL (11-20 weeks), 0.93 ± 0.12 ng/dL (21-30 weeks), 0.90 ± 0.13 ng/dL (31-36 weeks), and 0.80 ± 0.21 ng/dL (>36 weeks); and for TSH, values were (μIU/mL): 1.12 ± 0.69 (<10 weeks), 1.05 ± 0.67 (11-20 weeks), 1.19 ± 0.60 (21-30 weeks), 1.38 ± 0.76 (31-36 weeks), and 1.46 ± 0.72 (>36 weeks).
Pregnant women with normal antibody values according to gestational age had values for FT4 and TSH, but not for FT3, that differed to a statistically significant degree. The values we describe can be used as reference values for the Aragon region of Spain.
Hypothyroidism is believed to be a common health issue in India, as it is worldwide. However, there is a paucity of data on the prevalence of hypothyroidism in adult population of India.
Materials and Methods:
A cross-sectional, multi-centre, epidemiological study was conducted in eight major cities (Bangalore, Chennai, Delhi, Goa, Mumbai, Hyderabad, Ahmedabad and Kolkata) of India to study the prevalence of hypothyroidism among adult population. Thyroid abnormalities were diagnosed on the basis of laboratory results (serum FT3, FT4 and Thyroid Stimulating Hormone [TSH]). Patients with history of hypothyroidism and receiving levothyroxine therapy or those with serum free T4 <0.89 ng/dl and TSH >5.50 μU/ml, were categorized as hypothyroid. The prevalence of self reported and undetected hypothyroidism, and anti-thyroid peroxidase (anti-TPO) antibody positivity was assessed.
A total of 5376 adult male or non-pregnant female participants ≥18 years of age were enrolled, of which 5360 (mean age: 46 ± 14.68 years; 53.70% females) were evaluated. The overall prevalence of hypothyroidism was 10.95% (n = 587, 95% CI, 10.11-11.78) of which 7.48% (n = 401) patients self reported the condition, whereas 3.47% (n = 186) were previously undetected. Inland cities showed a higher prevalence of hypothyroidism as compared to coastal cities. A significantly higher (P < 0.05) proportion of females vs. males (15.86% vs 5.02%) and older vs. younger (13.11% vs 7.53%), adults were diagnosed with hypothyroidism. Additionally, 8.02% (n = 430) patients were diagnosed to have subclinical hypothyroidism (normal serum free T4 and TSH >5.50 μIU/ml). Anti – TPO antibodies suggesting autoimmunity were detected in 21.85% (n = 1171) patients.
The prevalence of hypothyroidism was high, affecting approximately one in 10 adults in the study population. Female gender and older age were found to have significant association with hypothyroidism. Subclinical hypothyroidism and anti-TPO antibody positivity were the other common observations.
Anti-TPO positive; epidemiology; free T3; free T4; hypothyroidism; India; prevalence; subclinical hypothyroidism; undetected hypothyroidism
Subclinical Hypothyroidism (ScHt) affects 3–15% of the adult population. It's clinical and biochemical profile is not well defined, especially in Indian scenario. Our study aimed at screening normal population to define normative ranges of thyroid hormones and Serum thyroid stimulating hormone (S.TSH) and prevalence of ScHt and thyroid autoimmunity.
Materials and Methods:
Two-hundred thirty-seven normal subjects without family history of thyroid disease were evaluated for symptoms and laboratory tests for thyroid dysfunction and autoimmunity.
The thyroid function tests were as follows:
Mean values were: T3: 1.79 ± 0.42 ng/mL, T4: 10.23 ± 2.25 μg/dL, FT3: 1.88 ± 0.19 pg/mL, FT4: 1.12 ± 0.21 ng/dL, S.TSH: 2.22 ± 1.06 μlu/mL. 10.2% of euthyroid subjects had antimicrosomal antibodies (AMA) +ve (mean titer 1:918) and 23.6% were anti-thyroid peroxidase autoantibody (anti-TPO) +ve (mean titer 15.06 Au/mL). The euthyroid outlier range for S.TSH was 0.3–4.6 μlu/mL. The values were comparable in both the sexes. Those with S.TSH ≥ 5 μlu/mL were defined to have ScHt.
Prevalence of ScHt was 11.3% (M:F ratio 1:3.7). 74% belonged to 35–54 years age group and prevalence increased with age (post-menopausal females: prevalence 20%). S.TSH was 9.8 ± 7.22 μlu/mL, mean S.AMA was 1:5079 (40.7% positivity) and mean S.anti-TPO was 260 Au/mL (47.6% positivity). Majority were agoitrous (74%), and stage I goiter was seen in 26% of this population. Symptom score of 5–8 was seen in 55% ScHt subjects versus 35% normal subjects.
Mean S.TSH in our population was 2.22 μlu/mL (euthyroid outliers: 0.3–4.6 μlu/mL); hence, S.TSH above 4.6 μlu/mL should be considered as abnormal. The prevalence of thyroid autoimmunity increases after age of 35 years. ScHt presents mainly in agoitrous form and with positive antibodies, suggesting autoimmunity as the cause.
Autoimmunity; normative ranges; prevalence; subclinical hypothyroidism
Aim. To investigate obstetric features of pregnant women with thyroid disorders and thyroid function tests of their newborn infants. Methods. Women with hypothyroidism and having anti-thyroglobulin (ATG) and anti-thyroid peroxidase (anti-TPO) antibodies were assigned as group I, women with hypothyroidism who did not have autoantibodies were assigned as group II, and women without thyroid problems were assigned as group III. Results. Pregnant women with autoimmune hypothyroidism (group I) had more preterm delivery and their babies needed more frequent neonatal intensive care unit (NICU) admission. In group I, one infant was diagnosed with compensated hypothyroidism and one infant had transient hyperthyrotropinemia. Five infants (23.8%) in group II had thyroid-stimulating hormone (TSH) levels >20 mIU/mL. Only two of them had TSH level >7 mIU/L at the 3rd postnatal week, and all had normal free T4 (FT4). Median maternal TSH level of these five infants with TSH >20 mIU/mL was 6.6 mIU/mL. In group III, six infants (6.5%) had TSH levels above >20 mIU/mL at the 1st postnatal week. Conclusion. Infants of mothers with thyroid problems are more likely to have elevated TSH and higher recall rate on neonatal thyroid screening. Women with thyroid disorders and their newborn infants should be followed closely for both obstetrical problems and for thyroid dysfunction.
There is a high incidence of thyroid dysfunction during pregnancy resulting in adverse maternal (miscarriages, anaemia in pregnancy, preeclampsia, abruptio placenta and post-partum haemorrhage) and fetal effects (premature birth, low birth weight, increased neonatal respiratory distress) which may justify screening for thyroid function during early pregnancy with interventional levothyroxine therapy for thyroid hypofunction. There is a greater prevalence of subclinical hypothyroidism in women with delivery before 32 weeks and there is even an association between thyroid autoimmunity and adverse obstetric outcome, which is independent of thyroid function. Higher maternal TSH levels even within the normal reference range are associated with an increased risk of miscarriages, fetal and neonatal distress and preterm delivery. There are few prospective randomised trials to substantiate the benefit of screening and the recently reported CATS study did not show a benefit in child IQ at age 3 years. Nevertheless there seems to be a case for screening to prevent adverse obstetric outcomes. The clinical epidemiological evidence base does not justify universal screening at the present time. However, it is probable that more evidence will be produced which may alter this view in the future.
Objective. We conducted the study to see the incidence of thyroid dysfunction in women with obstetrical high-risk factors. Methods. We retrospectively reviewed medical charts of high-risk pregnant women who had examination for thyroid function during pregnancy. Women were divided according to clinical presentation, symptoms of thyroid disease and those with a personal history of thyroid disease (thyroid disease, n = 32), intrauterine growth restriction (IUGR, n = 115), diabetes mellitus (diabetes, n = 115), hypertension (n = 63), intrauterine fetal death (IUFD, n = 52), and placental abruption (abruption, n = 15). The incidence of thyroid dysfunctions including hyperthyroidism or hypothyroidism was compared. Results. The overall prevalence of thyroid dysfunction was 24.7%. The incidence of thyroid dysfunction in each group was as follows: 31% in thyroid disease, 25% in IUGR, 30% in diabetes, 27% in hypertension, 12% in IUFD, and 7% in abruption. Except IUFD, the incidence was not statistically significant from the group of thyroid disease (thyroid disease versus IUFD, P = 0.03 by χ2 test). Thyroid disease represented for only 10% of all thyroid dysfunctions. Conclusion. Testing of women with a personal history or current symptoms of thyroid disease during pregnancy may be insufficient to detect women with thyroid dysfunction, who will become at high-risk pregnancy.
To determine the role of peak systolic velocity, end-diastolic velocity and resistance indices of both the right and left inferior thyroid arteries measured by color-flow Doppler ultrasonography for a differential diagnosis between gestational transient thyrotoxicosis and Graves' disease during pregnancy.
The right and left inferior thyroid artery-peak systolic velocity, end-diastolic velocity and resistance indices of 96 patients with thyrotoxicosis (41 with gestational transient thyrotoxicosis, 31 age-matched pregnant patients with Graves' disease and 24 age- and sex-matched non-pregnant patients with Graves' disease) and 25 age- and sex-matched healthy euthyroid subjects were assessed with color-flow Doppler ultrasonography.
The right and left inferior thyroid artery-peak systolic and end-diastolic velocities in patients with gestational transient thyrotoxicosis were found to be significantly lower than those of pregnant patients with Graves' disease and higher than those of healthy euthyroid subjects. However, the right and left inferior thyroid artery peak systolic and end-diastolic velocities in pregnant patients with Graves' disease were significantly lower than those of non-pregnant patients with Graves' disease. The right and left inferior thyroid artery peak systolic and end-diastolic velocities were positively correlated with TSH-receptor antibody levels. We found an overlap between the inferior thyroid artery-blood flow velocities in a considerable number of patients with gestational transient thyrotoxicosis and pregnant patients with Graves' disease.
This study suggests that the measurement of inferior thyroid artery-blood flow velocities with color-flow Doppler ultrasonography does not have sufficient sensitivity and specificity to be recommended as an initial diagnostic test for a differential diagnosis between gestational transient thyrotoxicosis and Graves' disease during pregnancy.
Gestational transient thyrotoxicosis; Graves' disease; Inferior thyroid artery; Color-flow Doppler ultrasonography; Pregnancy
Compartmental analysis of the peripheral distribution of labeled thyroxine was applied to various groups of subjects with thyrotoxicosis and hypothyroidism. It was observed that the hepatic incorporation of thyroxine was augmented in subjects with Graves' disease when compared to non-Graves' disease control groups at all levels of thyroid function. Decreased values of hepatic incorporation occurred in primary hypothyroid subjects. These lowered values were not acutely corrected by elevation of the serum thyroxine level, but were observed to be rectified after several months' therapy with exogenous thyroid hormone. These alterations of the hepatic thyroxine-131I incorporation were independently verified by direct quantitative liver scintiscan determinations.
Employing a dual thyroxine tracer system, we were able to demonstrate that during the early phases of equilibration of a tracer dose of thyroxine, alterations in the rate of deiodination were observed to be present in the various thyroid disease states. Increased deiodination rates were found in subjects with Graves' disease and the reverse was noted in patients with primary hypothyroidism. Kinetic analysis of thyroxine compartmental distribution during this early phase of equilibration of a labeled thyroxine tracer indicated that the primary tissue uptake occurred in the liver. These findings supported the contention that the amount of labeled thyroxine incorporated in the liver may be directly related to the deiodination rate of thyroxine by that organ. The pathogenetic basis of these alterations is presently unknown.
Observational studies have demonstrated that maternal thyroid dysfunction and thyroid autoimmunity in pregnancy may be associated with adverse obstetric and fetal outcomes. Treatment of overt maternal hyperthyroidism and overt hypothyroidism clearly improves outcomes. To date there is limited evidence that levothyroxine treatment of pregnant women with subclinical hypothyroidism, isolated hypothyroxinemia, or thyroid autoimmunity is beneficial. Therefore, there is ongoing debate regarding the need for universal screening for thyroid dysfunction during pregnancy. Current guidelines differ; some recommend an aggressive case-finding approach, whereas others advocate testing only symptomatic women or those with a personal history of thyroid disease or other associated medical conditions.
A high prevalence of postpartum thyroid dysfunction has been reported in several countries, but there have been no systematic studies of its prevalence in Britain. Among a group of 901 consecutive, unselected pregnant women thyroid autoantibodies were detected in 117 (13%) at booking. The clinical course of postpartum thyroid dysfunction, factors associated with its development, and its likely prevalence were defined in 100 of these women with thyroid antibodies and 120 women with no such antibodies who were matched for age. None of the women had a history of autoimmune thyroid disease. Normal reference ranges for thyroid function during pregnancy and post partum were established in the 120 women negative for thyroid antibodies. On the basis of these observations postpartum thyroid dysfunction was observed in 49 (22%) of the 220 women studied, and the prevalence in the total group of 901 women was estimated to be 16·7%. Thyroid dysfunction, mainly occurring in the first six months post partum, was usually transient and included both destruction induced hyperthyroidism and hypothyroidism. The development of the syndrome was significantly related to smoking more than 20 cigarettes a day and the presence of thyroid microsomal autoantibodies at booking. Of the 16 women with a family history of thyroid disease in whom thyroid microsomal autoantibody activity was detectable at booking, 11 developed thyroid dysfunction. Age, parity, presence of goitre at presentation, duration of breast feeding, and the sex and birth weight of the infant were not associated with the development of postpartum thyroid dysfunction.
The mood changes experienced by women post partum may in part be associated with altered thyroid function during this time.
Vitiligo is a common skin disorder, and the pathogenesis is unknown. An increased prevalence of autoimmune thyroid diseases has been described in these patients. The aim of this study is to assess the prevalence of thyroid dysfunction and hypoparathyroidism in patients with vitiligo.
Materials and Methods:
One hundred and nine patients (38 males and 71 females with vitiligo were enrolled. Thyroid physical examination was carried out. Thyroid function tests, thyroid antibodies, calcium and phosphorus were assessed. The collected data were analysed by SPSS version 11.
Thyromegaly was found in 30.1% of patients. Hypothyroidism was found in 16 (15.7%) out of 109 cases. Two of them had clinical and 14 had subclinical hypothyroidism. One patient had Grave's disease. Antibody positivity was the most common disorder (anti-TPO and anti-tg were positive in 36.7 and 32.1%, respectively). No patient had hypoparathyroidism.
According to our study, thyroid dysfunction, particulary hypothyroidism and thyroid antibodies increase in patients with vitiligo. We recommend thyroid antibodies assessment and thyroid function evaluation in these patients.
Thyroid antibodies; thyroid dysfunction; vitiligo
The aim of this study is to delineate laboratory diagnostic strategies for subclinical hypothyroidism in patients who are clinically symptomatic but may have a normal thyroid profile. Tri — iodothyronine (T3), thyroxine (T4), thyroid stimulating hormone (TSH) and anti thyroid peroxidase antibodies (anti-TPO) were estimated on fasting blood samples from 99 patients using electrochemiluminescence methods on ELECSYS 1010 (Roche). 74% of study subjects had elevated anti-TPO levels.61% patients had subclinical hypothyroidism. 45 of the 61 subclinical hypothyroid patients had elevated anti-TPO levels (73%). This is an important finding suggesting an autoimmune etiology for subclinical thyroid dysfunction with a higher risk of developing overt hypothyroidism.
Hypothyroidism; Thyroid Profile; T3; T4; TSH; Anti TPO
To evaluate the prevalence of thyroid dysfunction in elderly cardiac patients in an outpatient setting.
SUBJECTS AND METHODS:
A total of 399 consecutive patients (268 women, age range 60–92 years) who were followed at Heart Institute were evaluated for thyroid dysfunction with serum free T4, TSH, anti-Peroxidase antibodies, urinary iodine excretion measurements and thyroid ultrasound.
Hyperthyroidism (overt and subclinical) was present in 29 patients (6.5%), whereas hypothyroidism (overt and subclinical) was found in 32 individuals (8.1%). Cysts were detected in 11 patients (2.8%), single nodules were detected in 102 (25.6%), and multinodular goiters were detected in 34 (8.5%). Hashimoto’s thyroiditis was present in 16.8% patients, most of whom were women (83.6%). The serum TSH increased with age and was significantly higher (p= <0.01) in patients, compared to the normal control group. No significant differences in serum TSH and free T4 values were observed when patients with atrial fibrillation (AF) where compared with those without arrhythmia. The median urinary iodine levels were 210 μg/L (40–856 μg/L), and iodine levels were higher in men than in women (p<0.01). Excessive iodine intake (urinary iodine >300 μg/L) was observed in one-third of patients (30.8%).
Elderly patients have a higher prevalence of both hypo- and hyperthyroidism as well as thyroid nodules when compared with the general population. About one-third of the older patients had elevated urinary secretion of iodine and a higher prevalence of chronic Hashimoto’s thyroiditis. It is recommended that ultrasonographic studies, tests for thyroid function and autoimmunity should be evaluated in elderly patients.
Iodine intake; Thyroid dysfunction; Cardiologic patients; Elderly patients; Urinary iodine
Sarcopenia, the age-related decline in muscle mass, affects the muscle strength and muscle quality, and these changes decrease functional capacity. The prevalence of thyroid dysfunction increases with age, and changes in thyroid hormone level lead to neuromuscular deficits. We investigated the effects of subclinical hypothyroidism on the muscle mass, strength or quality in elderly people. One thousand one hundred eighteen subjects aged ≥65 yr were randomly selected from a local population and classified into a euthyroid (280 men and 358 women), subclinically hypothyroid (61 men and 75 women), or overtly hypothyroid (7 men and 16 women) group. Although women with subclinical hypothyroidism had a higher prevalence of sarcopenia, defined according to the ratio of appendicular skeletal muscle mass to the square of height, muscle mass, strength or quality did not differ in relation to thyroid status in men or in women. Multivariate analysis including age, diabetes, hypertension, acute coronary event, alcohol, smoking, presence of pain, physical activity score, and lipid profile, showed that thyroid-stimulating hormone level was not associated with muscle mass, strength or quality. In conclusion, subclinical hypothyroidism has little influences on muscle mass, strength or quality, and may not be associated with sarcopenia.
Sarcopenia; Subclinical Hypothyroidism; Aged
Subclinical hypothyroidism based on population and trimester specific cut-offs is reported to complicate 1-2% of all pregnancies. Using the recent Endocrine Society guidelines of 2.5 mIU/L of Thyroid Stimulating Hormone as the upper level of normal in the first trimester the reported prevalence of subclinical hypothyroidism is much higher. Recent publications have also emphasized that there is considerable racial variation in the prevalence of thyroid disorders in pregnancy. Among published literature North Indian women appear to have the highest rates of subclinical hypothyroidism in the first trimester of pregnancy. More widespread use of universal screening and trimester specific ranges in pregnancy for thyroid hormonal assays will lead to a large number of North Indian women requiring treatment for thyroid disorders in pregnancy.
First trimester; North India; pregnancy; subclinical hypothyroidism
It has been twenty years since the first paper reporting the association between thyroid antibodies (TAIs) and spontaneous miscarriage was published. Following this observation, several studies have clearly demonstrated an increased prevalence of TAI in patients with recurrent miscarriage (RM). However, the exact mechanism underlying this association remains a matter of debate. The aim of the present study was to evaluate the thyroid function, throughout a specific test, in patient with RM and TAI focusing on the hypothesis that TAI should be an indirect sign of a mild thyroid dysfunction. 46 patients with RM and TAI were included in the study. All patients underwent short TRH stimulation test showing an abnormal response in the vast majority of cases (65%). Normal FT4 and FT3 mean values were found whereas TSH values were in the upper normal range (2.64 ± 1.3 mUI/L). Our data support the hypothesis that in patients with RM the presence of TAI is an indirect sign of a subtle thyroid dysfunction detectable by a specific test. This test give the possibility to identify women with RM in which specific therapeutic approaches could effectively improve the possibility for a successful pregnancy.
Background. Hashimoto's thyroiditis (HT), also known as chronic lymphocytic thyroiditis or chronic autoimmune thyroiditis, is the most common form of thyroiditis affecting more than 10% of females and 2% of males. The present study aims to evaluate the beneficial effect of a combined treatment, Myo-Inositol plus selenomethionine, on subclinical hypothyroidism. Methods. The study was designed as a double-blind randomized controlled trial. Eligible patients were women diagnosed with subclinical hypothyroidism having Tg antibodies (TgAb) titer higher than 350 IU/mL. Outcome measures were Thyroid Stimulating Hormone (TSH) levels, thyroid peroxidase antibodies (TPOAb) and TgAb titer, selenium, and Myo-Inositol plasma concentration. Results. In the present paper, we demonstrated that the beneficial effects obtained by selenomethionine treatment on patients affected by subclinical hypothyroidism, likely due to the presence of autoantibody (TPOAb and TgAb), are further improved by cotreatment with Myo-Inositol. Conclusions. Indeed, due to its action as TSH second messenger, Myo-Inositol treatment reduces TSH levels closer to physiological concentrations.
Background: Autoimmune thyroid disease (AITD), a common organ specific autoimmune disorder is seen mostly in women between 30–50 yrs of age. Thyroid autoimmunity can cause several forms of thyroiditis ranging from hypothyroidism (Hashimoto’s thyroiditis) to hyperthyroidism (Graves’Disease). Prevalence rate of autoimmune mediated hypothyroidism is about 0.8 per 100 and 95% among them are women. Graves’ disease is about one tenth as common as hypothyroidism and tends to occur more in younger individuals. Both these disorders share many immunologic features and the disease may progress from one state to other as the autoimmune process changes. Genetic, environmental and endogenous factors are responsible for initiation of thyroid autoimmunity. At present the only confirmed genetic factor lies in HLA complex (HLA DR-3) and the T cell regulatory gene (CTLA 4). A number of environmental factors like viral infection, smoking, stress & iodine intake are associated with the disease progression. The development of antibodies to thyroid peroxidase (TPO) thyroglobulin (TG) and Thyroid stimulating hormone receptor (TSH R) is the main hallmark of AITD. Circulating T Lymphocytes are increased in AITD and thyroid gland is infiltrated with CD4+ and CD8+ T Cells. Wide varieties of cytokines are produced by infiltrated immune cells, which mediate cytotoxicity leading to thyroid cell destruction. Circulating antibodies to TPO and TG are measured by immunofluorescense, hemagglutination, ELISA & RIA. TSHR antibodies of Graves’ disease can be measured in bioassays or indirectly in assays that detect antibody binding to the receptor.
Autoimmune thyroid disease; thyroid peroxidase antibodies; Thyroglobulin antibodies; and TSHR antibodies
The mounting evidence linking hypothyroidism during pregnancy with poor pregnancy outcome underscores the need for screening and, therefore, a search for more reliable and cheaper screening methods.
The study was conducted in two phases. The phase one study comprised of healthy women in different stages of pregnancy who attended routine antenatal clinic at St Theresa's Maternity Hospital, Enugu, Nigeria from September 6 to October 18 1994. In this study the variables compared between the hypothyroid and non-hypothyroid pregnant women were maternal age, the number of the pregnancy or gravidity, gestational age, social class, body weight, height, the clinically assessed size of the thyroid gland, serum free thyroxin (FT4) and serum thyrotrophin (TSH). Based on the parameter differences between the two comparison groups of pregnant women two Logistic models, Model I and Model 11, were derived to differentiate the hypothyroid group from their non-hypothyroid counterparts. The two logistic models were then applied in a prospective validation study involving 197 pregnant women seen at presentation in Mother of Christ Specialist Hospital and Maternity, Ogui Road, Enugu from March 2002 to November 2007
The findings were that 82 (50.3%) of the 163 pregnant women had thyroid gland enlargement while 60 (36.8%) had hypothyroidism as defined by FT4 values below and/or TSH above their laboratory reference ranges. The pregnant subjects with hypothyroidism, compared with their non-hypothyroid counterparts, were characterized by a higher gravidity (p < 0.01), a higher body weight (p < 0.01), a higher goiter prevalence rate (p < 0.01) and a more advanced gestational age (p < 0.0001). A significant, positive correlation was also found between body weight and gestational age (r = 0.5; p < 0.01) At the cut-off point for Model l (fitted with gravidity, thyroid size and gestational age) it had a sensitivity of 100%, a specificity of 72.8% and an overall predictive accuracy of 82.9%; whereas for Model II (fitted with gravidity, thyroid size and body weight) the sensitivity was 100%, the specificity was 59.2% and the overall accuracy of discrimination was 74.8%. In the prospective validation study both models showed a sensitivity of 100% each with specificities of 85.5% for Model I and 76.2% for Model II.
It is concluded that logistic models fitting gravidity, thyroid gland size and gestational age or body weight are useful alternatives in screening for hypothyroidism during pregnancy. There is, however, a need for further independent confirmation of these findings.
Pregnancy; Thyroid hypo function; Prediction; Screening; Logistic models
To study pregnancy outcomes in relation to thyroid peroxidase antibody (TPOAb) status with optimum thyroxine replacement for subclinical hypothyroidism.
Materials and Methods:
Ninety-eight women with subclinical hypothyroidism were followed up until the end of their pregnancy. TPO antibody status was performed for 59 women (positive 20, negative 39). Levothyroxine was supplemented to maintain TSH between 0.3-3 mIU/l in all patients, irrespective of TPOAb status. Pregnancy outcomes were noted as pregnancy-induced hypertension (PIH), antepartum or postpartum hemorrhage, preterm delivery, and spontaneous abortion. Outcomes were compared between 3 groups as per TPO antibody status (positive, negative, and undetermined), which were matched for age and gestational period.
Thyroid autoimmunity was noted in 34% of women screened for TPO antibody. A total of 11 adverse pregnancy outcomes were recorded (4 spontaneous abortions, 4 preterm deliveries, 3 PIH) with no significant difference between the groups.
Adverse pregnancy outcomes were not different in the 3 groups with adequate thyroxine replacement for pregnant women with subclinical hypothyroidism targeting TSH in euthyroid range, irrespective of thyroid autoimmunity status.
Pregnancy; subclinical hypothyroidism; thyroid autoimmunity
The thyroidal response of pregnant patients with established Hashimoto's thyroiditis remains poorly described. The aim of this study was to determine the impact of pregnancy on Hashimoto's thyroiditis as revealed by changes in postpregnancy levothyroxine requirements.
We performed a retrospective study of 799 hypothyroid patients in a university hospital. We reviewed the clinical records and selected a group of well-documented pregnant (n = 34) and nonpregnant (n = 32) hypothyroid women for study. We reviewed levothyroxine intake and serum thyrotropin (TSH) levels during three consecutive 9-month time intervals that were immediately before, during, and after pregnancy. We compared the percent change in levothyroxine dose between the prepregnancy level and each trimester during and after pregnancy.
There were two patterns of levothyroxine supplementation during gestation. In pattern 1 (n = 11) there was either no change or a single levothyroxine dose increase with no subsequent changes in each trimester (T1 = T2 = T3). In pattern 2 (n = 18), multistep levothyroxine dose increases were required throughout pregnancy (T1 < T2 < T3) to maintain desired TSH levels (<2.0 mU/L). Women with pattern 2 had mean TSH levels during gestation that differed significantly from pattern 1 (2.8 ± 0.5 vs. 1.3 ± 0.1 mU/L respectively; p < 0.03). Further, in multivariate logistic regression, women with pattern 2 were 62 times more likely than women with pattern 1 to have a levothyroxine dose at least 20% above baseline at 3 months postpartum (p = 0.04).
We showed that >50% of hypothyroid women with Hashimoto's thyroiditis experienced an increase in levothyroxine requirements in the postpartum compared to pregestational doses. This pattern of enhanced levothyroxine need was most likely dependent on the preexisting thyroid functional reserve and postpartum progression of autoimmune destruction.
Although gestational hyperthyroidism is uncommon (0.2%), hypothyroidism (autoimmune disease or suboptimal iodine intake) occurs in 2.5% of women and is predictive of reduced neonatal and child neuropsychological development and maternal obstetric complications. Postpartum thyroid dysfunction (PPTD) occurs in 5–9% of women and is associated with antithyroid peroxidase antibodies (antiTPOAb) in 10% of women in early pregnancy. Therefore, screening for thyroid dysfunction in pregnancy should be considered. T4 and thyroid stimulating hormone measurements could be used to screen for hypothyroidism, which would require levothyroxine intervention treatment. T4 supply is crucial to fetal nervous system maturation; currently, the recommended daily iodine intake is 200 μg, and this is not always achieved, even in the UK. At present, a randomised prospective trial is ongoing to provide the evidence base for this screening strategy. Meanwhile, it is reasonable to (a) optimise iodine nutrition during pregnancy; (b) ascertain women with known thyroid disease; (c) identify women at increased risk of thyroid disease—for example, those with other autoimmune diseases. PPTD can be predicted by measurement of antiTPOAb in early gestation.
screening; thyroid; pregnancy; postpartum