Universal screening versus selective case-based screening for thyroid disorders in pregnancy

The role of blood testing in prevention, diagnosis, and management of chronic diseases: A review

Blood tests are vital to prevention, diagnosis, and management of chronic diseases. Despite this, it can be challenging to construct a comprehensive view of the clinical importance of blood testing because relevant literature is typically fragmented across different disease areas and patient populations. This lack of collated evidence can also make it difficult for primary care providers to adhere to best practices for blood testing across different diseases and guidelines. Thus, this review article synthesizes the recommendations for, and importance of, blood testing across several common chronic conditions encountered in primary care and internal medicine, including cardiovascular diseases, diabetes mellitus, chronic kidney disease, vitamin D deficiency, iron deficiency, and rheumatoid arthritis. Future research is needed to continue improving chronic disease management through clearer dissemination and awareness of clinical guidelines among providers, and better access to blood testing for patients (e.g., via pre-visit laboratory testing).

Do elevated thyrotropin levels increase the risk of miscarriages: yes or no?

BACKGROUND

To examine correlation between elevated levels of thyrotropin with the frequency of miscarriages.

METHODS

A cross-sectional study was conducted on the 380 respondents and it investigated TSH (thyrotropin), thyroid peroxidase antibody(anti-TPO) and free thyroxine (FT4) in pregnant women who had a miscarriage (N = 179) and pregnant women with normal pregnancies (N = 201).

RESULTS

The incidence of subclinical hypothyroidism in the miscarriages group was higher than in control group (61.4% vrs 15.79% (p < 0.001). In the miscarriages group with hypothyroidism (first trimester) mean value of TSH was significantly higher 4.31 ± 2.55 mIU/L compared to the control group 1.95 ± 0.86mIU/L (p < 0.001). Logistic multivariate regression revealed that TSH and body mass index (BMI) have a significant influence on the miscarriage; TSH level has a higher odds ratio (OR) 1.47 CI (95% 1.22-1.78) than BMI (OR) 1.14 CI (95% 1.06-1.23)) (p < 0.001). The combination of thyroid autoimmunity and TSH > 2.5mIU/L increase the risk of miscarriage (65.75%) compared to positive anti-TPO antibodies and TSH < 2.5mIU/L(14.15%)(p < 0.001).

CONCLUSIONS

Higher TSH levels correspond with obesity during early pregnancy and may be a sign of maternal thyroid dysfunction. Physiological thyroid function in the first trimester of pregnancy is important for perinatal outcome.

Screening for thyroid disease in pregnancy: a study of Danish clinical practice

BACKGROUND

Thyroid disease in pregnant women is a matter of clinical awareness, and current clinical guidelines recommend a risk-based screening strategy. This study aimed to evaluate current clinical practice regarding screening for thyroid disease in pregnancy in Denmark.

METHODS

A cross-sectional study was performed in the North Denmark Region with consecutive inclusion of 150 pregnant women from Aalborg University Hospital each year in 2020 and 2021. Medical records were reviewed according to the recommended risk-based screening criteria for thyroid disease in pregnancy. Any measurement of thyroid-stimulating hormone (TSH) was assessed 3 months prior to and in pregnancy.

RESULTS

Altogether 292 pregnant women who received no current treatment for thyroid disease were included. A total of 81 (27.7%) had a measurement of TSH before or during the pregnancy, and 30 women (10.3%) in the early pregnancy specifically. One or more of the screening criteria for thyroid disease recommended in the Danish clinical practice guideline were fulfilled in 37 of the 81 women (45.7%) with thyroid function tested and among 41 of the 211 (19.4%) women who did not have thyroid function tested before or during pregnancy.

CONCLUSION

In a Danish regional investigation, 1 in 4 women had their thyroid function tested in relation to a pregnancy. However, recommended risk-based screening criteria for thyroid disease in pregnancy were heterogeneously distributed. Results encourage considerations on the current practice for the screening of thyroid function in Danish pregnant women and inform the general debate.

The targeted high-risk case-finding approach versus universal screening for thyroid dysfunction during pregnancy: thyroid-stimulating hormone (TSH) and/or thyroid peroxidase antibody (TPOAb) test?

PURPOSE

To compare the effects of different thyroid screening scenarios, using the universal and targeted high-risk case-finding approaches with different diagnostic tests on the prevalence of subclinical hypothyroidism (SCH), thyroid autoimmunity, and pregnancy outcomes after adjustments for the intervention.

METHODS

During a secondary analysis of data collected in Tehran Thyroid and Pregnancy Study, a total of 2277 women from the total population, including 1303 high-risk individuals for thyroid dysfunction. The Cochran-Mantel-Haenszel method, adjusted for the intervention, was also used to evaluate the relationships between different screening scenarios [i.e., universal approach using thyroid-stimulating hormone (TSH) and/or thyroid peroxidase antibody (TPOAb) tests and targeted high-risk case-finding approach using TSH and/or TPOAb tests] and pregnancy outcomes (i.e., preterm delivery and NICU admission). The universal approach using both TSH and TPOAb measurements was considered as the reference scenario. We analyzed outcomes of different screening methods in individuals treated with LT4, compared to those individuals who were not treated.

RESULTS

Compared to the universal screening approach with both TSH and TPOAb measurements, the targeted high-risk case-finding approach overlooked approximately 42%, 62%, and 74% of women with elevated TSH (> 4 µlU/mL) when using both TSH and TPOAb tests, TSH alone, and TPO alone, respectively. After adjusting for the missed cases, 2.86% of women with preterm delivery and 2.76% of women with NICU admission were missed when they were screened using the targeted high-risk case-finding approach by measuring both TSH and TPOAb. The percentage of missed cases increased when applying the targeted approach with the TSH test alone, without measuring TPOAb. Overall, 4.16% and 4.02% of women with preterm delivery and NICU admission were overlooked in this scenario, respectively. After adjustments for the intervention, the probability of NICU admission in neonates of mothers, who were screened using the targeted high-risk case-finding approach with TPOAb measurement, was 2.31 folds higher than those screened by the reference scenario.

CONCLUSION

This study suggests that although the targeted high-risk case-finding approach including both TSH and TPOAb tests, may overlook some women with SCH, it is a reasonable option since it is not associated with a higher risk of adverse pregnancy outcomes.

Assessment and treatment of thyroid disorders in pregnancy and the postpartum period

Thyroid disorders are prevalent in pregnant women. Furthermore, thyroid hormone has a critical role in fetal development and thyroid dysfunction can adversely affect obstetric outcomes. Thus, the appropriate management of hyperthyroidism, most commonly caused by Graves disease, and hypothyroidism, which in iodine sufficient regions is most commonly caused by Hashimoto thyroiditis, in pregnancy is important for the health of both pregnant women and their offspring. Gestational transient thyrotoxicosis can also occur during pregnancy and should be differentiated from Graves disease. Effects of thyroid autoimmunity and subclinical hypothyroidism in pregnancy remain controversial. Iodine deficiency is the leading cause of hypothyroidism worldwide. Despite global efforts to eradicate iodine deficiency disorders, pregnant women remain at risk of iodine deficiency due to increased iodine requirements during gestation. The incidence of thyroid cancer is increasing worldwide, including in young adults. As such, the diagnosis of thyroid nodules or thyroid cancer during pregnancy is becoming more frequent. The evaluation and management of thyroid nodules and thyroid cancer in pregnancy pose a particular challenge. Postpartum thyroiditis can occur up to 1 year after delivery and must be differentiated from other forms of thyroid dysfunction, as treatment differs. This Review provides current evidence and recommendations for the evaluation and management of thyroid disorders in pregnancy and in the postpartum period.

Health-related quality of life in women with autoimmune thyroid disease during pregnancy and postpartum: systematic review including 321,850 pregnancies

BACKGROUND

Utilities of the general population or expert estimates have been used for all published cost-effectiveness analyses of screening for thyroid disorders in pregnancy.

METHODS

A systematic review CRD42019120897 of studies with patient-reported outcomes (PRO) and laboratory evidence of thyroid function/autoimmunity was conducted using PubMed, Cochrane Central, EconLit, SocIndex, DARE, NHS EEDS, Annual Reviews, and CINAHL. Quality was assessed using Joanna Briggs Institute appraisal tool.

RESULTS

Of 664 abstracts screened, we analyzed 97 full texts. All studies describing the impact of thyroid disease on the generic QoL excluded pregnant and postpartum women. 21 reports of acceptable quality (321,850 pregnancies) determined depression and anxiety with validated tools and/or reported subjective symptoms. During pregnancy, contradictory conclusions were published on the impact of thyroid disease on PRO. Postpartum, antithyroid antibodies coincide with alexithymia and depression, postpartum thyroiditis negatively impacts mood. No conclusion could be drawn on the impact of thyroid hormonal levels.

CONCLUSIONS

The generic QoL in autoimmune thyroid disease during pregnancy has never been described, which represents an obstacle for the construction of economic models. We found contradictory information on the impact of thyroid disease on depression, anxiety, and specific symptoms.

Surface modified halloysite nanotube enhanced imine-based epoxy composites with high self-healing efficiency and excellent mechanical properties

(a) Schematic diagram of the self-healing mechanism. (b) Illustration of the cross-linking effect and the internal molecular structure.

Selective case finding versus universal screening for detecting hypothyroidism in the first trimester of pregnancy: a comparative evaluation of a group of pregnant women from Rio de Janeiro

Objective Maternal hypothyroidism during pregnancy may lead to adverse outcomes. Recently published guidelines by the American Thyroid Association (ATA) do not advocate for universal screening but recommend a case-finding approach in high-risk pregnant women. The present study aims to evaluate the accuracy of this approach in identifying women with thyroid dysfunction during early pregnancy. Subjects and methods This is a multiple-center, cross-sectional study. Three hundred and one pregnant women were enrolled. Anamnesis and a physical examination were performed to detect which women fulfilled the criteria to undergo laboratory screening of thyroid dysfunction, according to the ATA's 2017 guidelines. The Zulewski's validated clinical score was applied to assess signs and symptoms of hypothyroidism. Serum levels of thyrotropin (TSH), free thyroxine (FT4), anti-thyroperoxidase (TPO-Ab), and anti-thyroglobulin (Tg-Ab) antibodies were determined. Results Two hundred and thirty one women (78%) were classified as high risk, and 65 (22%) were classified as low risk for thyroid dysfunction. Regarding the clinical score, 75 patients (31.2%) presented mild symptoms that were compatible with SCH, of which 22 (7.4%) had symptoms as the only risk factor for thyroid disease. 17 patients (5.7%) had SCH, of which 10 (58.8%) belonged to the high-risk group, and 7 (41.2%) belonged to the low-risk group. OH was found in 4 patients (1.4%): 3 (75%) in the high-risk group and 1 (25%) in the low-risk group. Conclusions The ATA's proposed screening criteria were not accurate in the diagnosis of thyroid dysfunction in pregnancy. Testing only the high-risk pregnant women would miss approximately 40% of all hypothyroid patients.

Validation of Billewicz Scoring System for Detection of Overt Hypothyroidism During Pregnancy

BACKGROUND

Currently, various clinical and laboratory diagnostic methods are used to detect overt hypothyroidism during pregnancy. The Billewicz scoring index, as a clinical scale for detection of hypothyroidism, has been applied in general populations; however, its application during pregnancy remains a controversial subject of ongoing research.

OBJECTIVES

The purpose of this study was to evaluate the diagnostic value of Billewicz scoring index for overt hypothyroidism in a general population of Iranian pregnant women.

METHODS

This study was conducted on 1843 pregnant women. A comprehensive questionnaire, including Billewicz scoring items, was completed, and relevant clinical examinations were performed. The participants underwent serum measurements of thyroxine (T4), thyroid hormone uptake, thyroid-stimulating hormone (TSH), and thyroid peroxidase antibody (TPOAb). Using the receiver operating characteristic (ROC) curve analysis, the optimal sensitivity and specificity were determined as values with maximum yields on the Youden and Rsquo's Index (sensitivity + specificity-1).

RESULTS

The prevalence of overt hypothyroidism and subclinical hypothyroidism was 3.3% and 28.6%, respectively. Overall, 3.6%, 18.9%, and 50% of euthyroid, subclinical hypothyroid, and overt hypothyroid women were TPOAb-positive, respectively. The mean Billewicz scores of euthyroid, overt hypothyroid, and subclinical hypothyroid women were -41.16 (11.16), -17.11 (13.63), and -40.1 (11.2), respectively. Based on the Billewicz scale, at least one sign of hypothyroidism was reported in 38.84% (n, 491) of euthyroid women. Scores ≤ -26.5 (sensitivity, 100%; specificity, 90.82%) were considered as the optimal scores for predicting overt hypothyroidism (Ldquo, Norisk, and Rsquo).

CONCLUSIONS

The Billewicz clinical scoring system, as a reliable and inexpensive clinical tool, used along with laboratory measurements, can help screen overt hypothyroidism during pregnancy, primarily in low-resource settings.

Controlled Antenatal Thyroid Screening II: Effect of Treating Maternal Suboptimal Thyroid Function on Child Cognition

CONTEXT AND OBJECTIVE

The Controlled Antenatal Thyroid Screening (CATS) study investigated treatment of suboptimal gestational thyroid function (SGTF) on childhood cognition and found no difference in intelligence quotient (IQ) at 3 years between children of treated and untreated SGTF mothers. We have measured IQ in the same children at age 9.5 years and included children from normal gestational thyroid function (normal-GTF) mothers.

DESIGN, SETTING, AND PARTICIPANTS

One examiner, blinded to participant group, assessed children's IQ (Wechsler Intelligence Scale for Children, Fourth Edition UK), long-term memory, and motor function (Developmental Neuropsychological Assessment II) from children of 119 treated and 98 untreated SGTF mothers plus children of 232 mothers with normal-GTF. Logistic regression explored the odds and percentages of an IQ < 85 in the groups.

RESULTS

There was no difference in IQ < 85 between children of mothers with normal-GTF and combined SGTF, i.e., treated and untreated (fully adjusted odds ratio [OR] = 1.15 [95% confidence interval (CI) 0.52, 2.51]; P = 0.731). Furthermore, there was no significant effect of treatment [untreated OR = 1.33 (95% CI 0.53, 3.34); treated OR = 0.75 (95% CI 0.27, 2.06) P = 0.576]. IQ < 85 was 6.03% in normal-GTF, 7.56% in treated, and 11.22% in untreated groups. Analyses accounting for treated-SGTF women with free thyroxine > 97.5th percentile of the entire CATS-I cohort revealed no significant effect on a child's IQ < 85 in CATS-II. IQ at age 3 predicted IQ at age 9.5 (P < 0.0001) and accounted for 45% of the variation.

CONCLUSIONS

Maternal thyroxine during pregnancy did not improve child cognition at age 9.5 years. Our findings confirmed CATS-I and suggest that the lack of treatment effect may be a result of the similar proportion of IQ < 85 in children of women with normal-GTF and SGTF.

Thyroid disease symptoms during early pregnancy do not identify women with thyroid hypofunction that should be treated

OBJECTIVE

To evaluate whether women during early pregnancy with "hypothyroidism" symptoms are at risk of biochemically defined hypothyroidism. The 2017 Guidelines of the American Thyroid Association (ATA) recommend case-finding on the basis of symptoms to identify these women during pregnancy, while evidence is lacking.

DESIGN

Construct validation of a thyroid hypofunction symptom checklist during the first trimester of pregnancy comparing high scores with biochemically defined hypothyroidism.

PATIENTS

A total of 2198 healthy pregnant women from an iodine-sufficient area in 2013-2014.

MEASUREMENTS

Completion of a draft questionnaire with "classical" symptoms of hypothyroidism at 12 weeks of gestation. The 2.5th and 97.5th percentiles of TSH and fT4 during pregnancy in TPO-Ab-negative (<35 kU/L) women were used to define euthyroid women and those with overt (clinical) and subclinical hypothyroidism. The prevalence of overt (subclinical) hypothyroidism was compared between women with high symptom scores and those with low symptom scores.

RESULTS

According to fT4 and TSH cut-offs (0.23-4.0 mIU/L and 11.5-18.0 pmol/L, respectively), there were 15 women with "to treat hypofunction" (overt hypothyroidism or TSH >10 mIU/L) and 68 women with subclinical hypothyroidism. Questionnaire construct validation revealed a 12-item hypothyroid checklist with normally distributed scores. The cut-off indicating high scores of OH was set at 1 SD > mean. Women with high symptom scores did not present more often with biochemically defined thyroid hypofunction.

CONCLUSION

This study does not support the ATA recommendation that pregnant women who require levothyroxine therapy can be identified by case-based screening of women with symptoms of thyroid disease.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY POSITION STATEMENT ON THYROID DYSFUNCTION CASE FINDING

Hypothyroidism and hyperthyroidism can be readily diagnosed and can be treated in a safe, cost-effective manner. Professional organizations have given guidance on how and when to employ thyroid-stimulating hormone testing for the detection of thyroid dysfunction. Most recently, the United States Preventive Services Task Force did not endorse screening for thyroid dysfunction based on a lack of proven benefit and potential harm of treating those with thyroid dysfunction, which is mostly subclinical disease. The American Association of Clinical Endocrinologists (AACE) is concerned that this may discourage physicians from testing for thyroid dysfunction when clinically appropriate. Given the lack of specificity of thyroid-associated symptoms, the appropriate diagnosis of thyroid disease requires biochemical confirmation. The Thyroid Scientific Committee of the AACE has produced this White Paper to highlight the important difference between screening and case-based testing in the practice of clinical medicine. We recommend that thyroid dysfunction should be frequently considered as a potential etiology for many of the nonspecific complaints that physicians face daily. The application and success of safe and effective interventions are dependent on an accurate diagnosis. We, therefore, advocate for an aggressive case-finding approach, based on identifying those persons most likely to have thyroid disease that will benefit from its treatment.

High Body Mass Index Is an Indicator of Maternal Hypothyroidism, Hypothyroxinemia, and Thyroid-Peroxidase Antibody Positivity during Early Pregnancy

Background. Maternal thyroid dysfunction in early pregnancy may increase the risk of adverse pregnancy complications and neurocognitive deficiencies in the developing fetus. Currently, some researchers demonstrated that body mass index (BMI) is associated with thyroid function in nonpregnant population. Hence, the American Thyroid Association recommended screening thyroid function in obese pregnant women; however, the evidence for this is weak. For this purpose, our study investigated the relationship between high BMI and thyroid functions during early pregnancy in Liaoning province, an iodine-sufficient region of China. Methods. Serum thyroid stimulating hormone (TSH), free thyroxine (FT4), thyroid-peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb) concentration, urinary iodine concentration (UIC), and BMI were determined in 6303 pregnant women. Results. BMI ≥ 25 kg/m² may act as an indicator of hypothyroxinemia and TPOAb positivity and BMI ≥ 30 kg/m² was associated with increases in the odds of hypothyroidism, hypothyroxinemia, and TPOAb positivity. The prevalence of isolated hypothyroxinemia increased among pregnant women with BMI > 24 kg/m². Conclusions. High BMI during early pregnancy may be an indicator of maternal thyroid dysfunction; for Asian women whose BMI > 24 kg/m² and who are within 8 weeks of pregnancy, thyroid functions should be assessed especially.