scholarly journals Trimester- and Assay-Specific Thyroid Reference Intervals for Pregnant Women in China

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Jinfang Xing ◽  
Enwu Yuan ◽  
Jing Li ◽  
Yuchao Zhang ◽  
Xiangying Meng ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Chinese Women ◽  
Reference Interval ◽  
First Trimester ◽  
Cross Sectional Study ◽  
Reference Intervals ◽  
Thyroid Stimulating Hormone ◽  
Thyroid Peroxidase ◽  
American Thyroid Association ◽  
Cross Sectional

Objective. The guidelines of the American Thyroid Association (ATA) recommend an upper limit reference interval (RI) of thyroid stimulating hormone (TSH) of 2.5 mIU/L in the first trimester of pregnancy and 3.0 mIU/L in subsequent trimesters, but some reported ranges in China are significantly higher. Our study aimed to establish trimester- and assay-specific RIs for thyroid hormones in normal pregnant Chinese women. Methods. In this cross-sectional study, 2540 women with normal pregnancies (first trimester, n=398; second trimester, n=797; third trimester, n=1345) and 237 healthy nonpregnant control subjects were recruited. Serum TSH, free thyroxin (FT4), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) levels were determined by automated chemiluminescence with an Immulite 2000 system (Siemens, Erlangen, Germany). After outliers were excluded, the 2.5–97.5th percentiles were used to define the RIs. Results. The RIs of thyroid function in the first, second, and third trimesters of pregnancy and in nonpregnant controls were 0.07–3.96, 0.27–4.53, 0.48–5.40, and 0.69–5.78 mIU/L for TSH and 9.16–18.12, 8.67–16.21, 7.80–13.90, and 8.24–16.61 pmol/L for FT4, respectively. Conclusion. The trimester- and assay-specific RIs of thyroid function during pregnancy differed between trimesters, which suggests that it is advisable to detect and avoid misclassification of thyroid dysfunction during pregnancy for women in Henan, China.

Establishment of trimester-specific thyroid stimulating hormone and free thyroxine reference interval in pregnant Chinese women using the Beckman Coulter UniCel™ DxI 600

2015 ◽  
Vol 53 (9) ◽  
Author(s):  
Jing Zhang ◽  
Wei Li ◽  
Qiao-Bin Chen ◽  
Li-Yi Liu ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Chinese Women ◽  
Reference Interval ◽  
Reference Intervals ◽  
Thyroid Stimulating Hormone ◽  
Free Thyroxine ◽  
Specific Reference ◽  
Thyroid Peroxidase ◽  
Cross Sectional ◽  
Reported Data ◽  
Stimulating Hormone

AbstractThyroid-stimulating hormone (TSH) and free thyroxine (FT4) reference intervals are essential for screening and diagnosing thyroid dysfunction during pregnancy. The aim of this study was to establish method- and trimester-specific TSH and FT4 reference intervals in pregnant Chinese women using the Beckman Coulter UniCel™ DxI 600.A cross-sectional dataset analysis was performed. A total of 3507 participants were recruited, and 2743 were eligible for analysis to set reference intervals. TSH, FT4, and thyroid peroxidase antibody (TPOAb) levels were analyzed with the Beckman Coulter UniCel™ DxI 600 AccessThe calculated reference intervals for the first, second, and third trimesters were TSH: 0.06–3.13, 0.07–4.13 and 0.15–5.02 mIU/L, respectively, and FT4: 8.72–15.22, 7.10–13.55 and 6.16–12.03 pmol/L, respectively.Our reference intervals for TSH and FT4 are distinct from the ranges reported in the DxI 600 instruction manual and previously reported data, confirming the importance of method-specific reference intervals.

scholarly journals Reference Intervals of Thyroid Hormones and Correlation of BMI with Thyroid Function in Healthy Zhuang Ethnic Pregnant Women

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yonghong Sheng ◽  
Dongping Huang ◽  
Shun Liu ◽  
Xuefeng Guo ◽  
Jiehua Chen ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Pregnant Women ◽  
Thyroid Function ◽  
Reference Intervals ◽  
Thyroid Stimulating Hormone ◽  
Specific Reference ◽  
American Thyroid Association ◽  
Reference Ranges ◽  
Free Triiodothyronine ◽  
Cross Sectional

Ethnic differences in the level of thyroid hormones exist among individuals. The American Thyroid Association (ATA) recommends that an institution or region should establish a specific thyroid hormone reference value for each stage of pregnancy. To date, a limited number of studies have reported the level of thyroid hormones in Chinese minorities, and the exact relationship between BMI and thyroid function in pregnant women is ill. This study was performed to establish trimester-specific reference ranges of thyroid hormones in Zhuang ethnic pregnant women and explore the role of body mass index (BMI) on thyroid function. A total of 3324 Zhuang ethnic health pregnant women were recruited in this Zhuang population-based retrospective cross-sectional study. The values of thyroid stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3) were determined by automatic chemiluminescence immunoassay analyzer. Multivariate linear regression and binary logistic regression were constructed to evaluate the influence of BMI on the thyroid function. The established reference intervals for the serum thyroid hormones in three trimesters were as follows: TSH, 0.02–3.28, 0.03–3.22, and 0.08-3.71 mIU/L; FT4, 10.57–19.76, 10.05–19.23, and 8.96–17.75 pmol/L; FT3, 3.51–5.64, 3.42–5.42, and 2.93–5.03 pmol/L. These values were markedly lower than those provided by the manufacturers for nonpregnant adults which can potentially result in 6.10% to 19.73% misclassification in Zhuang pregnant women. Moreover, BMI was positively correlated with isolated hypothyroxinemia (OR=1.081, 95% CI=1.007–1.161), while the correlation between the BMI and subclinical hypothyroidism was not statistically significant (OR=0.991, 95% CI=0.917–1.072). This is the first study focusing on the reference ranges of thyroid hormones in Guangxi Zhuang ethnic pregnant women, which will improve the care of them in the diagnosis and treatment. We also found that high BMI was positively associated with the risk of isolated hypothyroxinemia.

scholarly journals Second-Trimester Reference Intervals for Thyroid Tests: The Role of Ethnicity

2007 ◽  
Vol 53 (9) ◽  
pp. 1658-1664 ◽  
Author(s):  
Sonia L La’ulu ◽  
William L Roberts
Keyword(s):  
Thyroid Function ◽  
Thyroid Function Test ◽  
Reference Interval ◽  
Reference Intervals ◽  
Thyroid Stimulating Hormone ◽  
Adverse Outcomes ◽  
Thyroid Peroxidase ◽  
Serum Samples ◽  
Free Triiodothyronine ◽  
Thyroglobulin Autoantibodies

Abstract Background: Thyroid function changes during pregnancy, complicating the diagnosis of thyroid disorders. Maternal thyroid dysfunction has been associated with a variety of adverse outcomes. We evaluated thyroid function test results by ethnicity and week of gestation during the 2nd trimester of pregnancy. Methods: We collected 3064 blood specimens in serum tubes from Asians (13%), blacks (22%), Hispanics (23%), and whites (42%). We measured thyroid-stimulating hormone (TSH), total and free thyroxine (TT4 and FT4), total and free triiodothyronine (TT3 and FT3), thyroglobulin autoantibodies (TgAb), and thyroid peroxidase autoantibodies (TPOAb) by use of an ARCHITECT i2000SR (Abbott Diagnostics). The TSH reference interval was calculated for samples negative for both TgAb and TPOAb and reference intervals for TT4, FT4, TT3, and FT3 in antibody-negative samples with normal TSH. Results: Serum samples were positive for TgAb in 10.6%, 1.8%, 6.2%, 6.5%, and 5.9% of Asian, black, Hispanic, white, and combined groups, respectively. Samples were positive for TPOAb in 12.4%, 4.1%, 11.8%, 12.3%, and 10.4% of the same groups, respectively. The nonparametric reference intervals for all participants were 0.15–3.11 mIU/L (TSH), 9.3–15.2 pmol/L (0.72–1.18 ng/dL; FT4), 89.0–176.3 nmol/L (6.90–13.67 μg/dL; TT4), 3.82–5.96 pmol/L (2.48–3.87 pg/mL; FT3), and 1.82–3.68 nmol/L (118–239 ng/dL; TT3). Conclusions: Blacks had lower prevalences of TgAb and TPOAb positivity and of increased serum TSH. The prevalence of TgAb and TPOAb positivity was highest in Asians. Whites had the highest prevalence of increased TSH. The lower and upper reference limits of TT3 were significantly lower for Asians. Reference intervals for women in the 2nd trimester were different from those of nonpregnant individuals.

scholarly journals Maternal thyroid function test level during the first trimester of pregnancy at a center Yazd, Iran: A cross-sectional study

2021 ◽  
Author(s):  
Farahnaz Farzaneh ◽  
Farzaneh Khastehfekr
Keyword(s):  
Thyroid Hormones ◽  
Thyroid Function ◽  
First Trimester ◽  
Cross Sectional Study ◽  
Reference Intervals ◽  
Reference Ranges ◽  
Thyroid Function Tests ◽  
Sectional Study ◽  
Cross Sectional ◽  
First Trimester Of Pregnancy

Background: Thyroid dysfunction is associated with negative pregnancy outcomes. There is a lack of reliable information on thyroid hormones in Iranian pregnant women, especially in Yazd. Objective: To determine the safe thyroid hormone levels in women of Yazd and also the first trimester-specific reference ranges for serum thyroid-stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3). Materials and Methods: In this cross-sectional study, the serum of 1,148 women in the first trimester of pregnancy was analyzed. Thyroid function tests (TSH, T4, T3) were measured through radioimmunoassay (RIA) [immunoradiometric (IRMA) for TSH]. The study was conducted in Yazd, from September 2018 to November 2019. Reference intervals were defined as the 5th, 50th, and 95th percentiles. Results: The mean age of the participants was 28.78 (± 5.86 yr) (range: 15-45 yr). The thyroid hormones reference intervals in the first trimester were TSH (0.2-3.8 mIU/l), T4 (7.45-12.75, μg/dl), and T3 (100-217 ng/dl). Conclusion: The results of the present study determined a local thyroid function measurement in the first trimester of pregnancy at a center of Yazd, Iran. This could facilitate the decision-making of maternal TSH level during the first trimester of pregnancy. Key words: First pregnancy trimester, Thyrotropin, Thyroxine, Triiodothyronine.

scholarly journals HbA1c is inversely associated with thyroid cysts in a euthyroid population: A cross-sectional study

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253841
Author(s):  
Yuji Shimizu ◽  
Shin-Ya Kawashiri ◽  
Yuko Noguchi ◽  
Yasuhiro Nagata ◽  
Takahiro Maeda ◽  
...  
Keyword(s):  
Thyroid Function ◽  
Cross Sectional Study ◽  
Thyroid Stimulating Hormone ◽  
Thyroid Peroxidase ◽  
Sectional Study ◽  
Normal Range ◽  
Free Triiodothyronine ◽  
Free T4 ◽  
Cross Sectional ◽  
Normal Thyroid Function

Anti-thyroid peroxidase antibody (TPO-Ab) is revealed to be inversely associated with thyroid cysts among euthyroid population. TPO-Ab causes autoimmune thyroiditis by bolstering thyroid inflammation. Therefore, at least partly, absence of thyroid cysts could indicate latent thyroid damage. Since participants with subclinical hypothyroidism are reported to have higher HbA1c than normal healthy controls, HbA1c could be inversely associated with thyroid cysts through a mechanism reflecting latent thyroid damage. To investigate the association between HbA1c and thyroid cysts among a euthyroid population, a cross-sectional study was conducted on 1,724 Japanese individuals who were within the normal range of thyroid function [i.e., normal range of free triiodothyronine (T3) and free thyroxine (T4)] and aged 40–74 years. Among this study population, 564 were diagnosed with thyroid cysts. Independently of thyroid related hormones [thyroid stimulating hormone (TSH), free T3, and free T4] and known cardiovascular risk factors, HbA1c was found to be significantly inversely associated with the presence of thyroid cysts. This association remained significant even after this analysis was limited to participants within a normal range of TSH. The fully adjusted odds ratios (ORs) of thyroid cysts for 1 standard deviation (SD) increment of HbA1c were 0.84 (0.74, 0.95) for total participants and 0.80 (0.70, 0.92) for participants within a normal range of TSH. Among participants with normal thyroid function, HbA1c was inversely associated with the presence of thyroid cysts. The absence of thyroid cysts and higher levels of HbA1c could indicate the latent functional damage of the thyroid.

scholarly journals Distribution of thyroid peroxidase positivity and its effects on thyroid function in normal pregnant women during 1st trimester in Dhaka city

2014 ◽  
Vol 4 (1) ◽  
pp. 15-20
Author(s):  
Ohida Sultanaa ◽  
Nasim Jahan ◽  
Nayma Sultana ◽  
Farzana Mahmudad ◽  
Tazdik G Chowdhurye
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
First Trimester ◽  
Normal Pregnancy ◽  
Control Group ◽  
Thyroid Peroxidase ◽  
Study Group ◽  
Cross Sectional ◽  
Total Study Population ◽  
Group B

Objective: To measure the distribution of TPO-Ab positivity and to observe the effect of thyroid peroxidase positivity on thyroid function during first trimester in normal pregnancy. Method: A cross sectional among 120 subjects were taken in this study and divided into control and study groups. Control group (Group A) consisted of 60 healthy non pregnant women age ranged between 20 to 35 years. Study group (Group B) consisted of 60 normal pregnant women of same age range. Group B was further subdivided into group B1 and group B2according to the level of TPO-Ab. Group B1 consisted of TPO-Ab positive pregnant women and group B2 consisted of TPO- Ab negative pregnant women. Control group was selected from personal contacts and study group from Out Patient Department (OPD) of Obstetrics and Gynecology of Sir Salimullah Medical College and Mitford Hospital. For assessment of thyroid function, serum free thyroxine (FT4), thyroid stimulating hormone (TSH) were measured. Serum FT4, TSH were measured by Enzyme link immunosorbant (ELISA) method. Again, serum TPO-Ab of total study population and hCG of all the pregnant women were measured. Serum TPO-Ab by Micro particle Enzyme Immunoassay (MEIA) method and hCG was estimated by ELISA. Statistical analysis was done by SPSS version 17. Results: In this study, serum FT4 and was significantly (P<0.001) higher and TSH level was significantly (P<0.001) lower in normal pregnant women during 1st trimester in comparison to those of non pregnant women. Again, 18% of pregnant women showed TPO-Ab positivity. However, serum FT4 level was significantly (P<0.001) lower whereas, TSH level was significantly (p<0.001) higher in TPO-Ab positive pregnant women in comparison to those of TPO-Ab negative pregnant women. Conclusion: TPO-Ab positivity increases during 1st trimester of normal pregnancy which decreases the hyper functional state of thyroid hormones. So, thyroid screening should be done routinely during pregnancy. DOI: http://dx.doi.org/10.3329/updcj.v4i1.21160 Update Dent. Coll. j: 2014; 4 (1): 15-20

scholarly journals Assessment of physical activity status among pregnant women in southwestern China

2019 ◽  
Vol 6 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Ya-Nan Yin ◽  
Yan Huang ◽  
Xing-Hui Liu ◽  
Bi-Ru Luo
Keyword(s):  
Physical Activity ◽  
Pregnant Women ◽  
Health Care Providers ◽  
Chinese Women ◽  
First Trimester ◽  
Cross Sectional Study ◽  
Southwestern China ◽  
Care Providers ◽  
Cross Sectional ◽  
Exercise During Pregnancy

Abstract Objective To assess the patterns and intensities of physical activity among pregnant women in southwestern China, which help us create a fitness regimen based on the 2002 American College of Obstetricians and Gynecologists (ACOG) guidelines for exercise during pregnancy. Methods A cross-sectional study was performed to recruit pregnant women at a prenatal checking visit clinic with the self-administered Chinese version of Pregnancy Physical Activity Questionnaire (PPAQ). Results A total of 1179 Chinese pregnant women were enrolled, of whom 92.60% were classified as not meeting the ACOG guidelines. By intensity, 47.36% of the score was attributed to light-intensity activities (1.5 to <3.0 metabolic equivalent [MET]) in the first trimester; the other 2 trimesters were similar. By patterns, about 45.15% of the score was attributed to inactivity. More than 82.35% of enrolled pregnant women regarded slowly walking as the most common type of exercise during pregnancy. Conclusions This study represents a group of Chinese women who maintained an inactive lifestyle, including low-intensity activities and unitary type of exercises during their pregnancy. Health-care providers are advised to provide appropriate physical activity guidelines to pregnant women. Development of MET-hours/week recommendations is warranted to promote greater physical activity during pregnancy.

scholarly journals Trimester-specific reference ranges for thyroid hormones of pregnant females at tertiary care hospitals in Lahore, Pakistan

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Asim Mumtaz ◽  
Fauzia Sadiq ◽  
Saima Zaki ◽  
Hijab Batool ◽  
Muhammad Ibrahim ◽  
...  
Keyword(s):  
Tertiary Care ◽  
Thyroid Function Test ◽  
Cross Sectional Study ◽  
Thyroid Stimulating Hormone ◽  
Specific Reference ◽  
Thyroid Peroxidase ◽  
Reference Ranges ◽  
Cross Sectional ◽  
Pregnant Females ◽  
Tertiary Care Hospitals

Abstract Background The significance of investigation for diagnosing and managing thyroid dysfunction in pregnant females has been extensively documented in the medical literature. This study aimed to determine trimester-specific reference ranges for thyroid-stimulating hormones (TSH), free T3 (FT3), and free T4 (FT4) in apparently healthy pregnant women attending tertiary care hospitals in Lahore. Methods This cross-sectional study was conducted at two tertiary care Hospitals in Lahore, Pakistan. In this multi-centric study, 500 pregnant females were initially enrolled from September 2019 to December 2019 who fulfilled the inclusion criteria. For measurement of serum FT3, FT4, thyroid stimulating hormone (TSH), anti-thyroid peroxidase (anti-TPO), and thyroglobulin antibodies, 5 ml of the blood sample was drawn, under aseptic conditions, from each subject using Maglumi 800 chemiluminescence immunoassay (CLIA) system. Results Out of 500 subjects, 23 subjects with positive anti-TPO, 19 subjects with anti-TG antibodies, and 12 subjects due to less volume of serum yielded from whole blood (serum less than 3 ml) were excluded from the analysis. Ten samples were hemolyzed and not included in the analysis. A total of 436 samples were examined for analysis. Of the remaining 436 subjects, 133 (30.5%) were from 1st trimester, 153 (35.1%) from 2nd trimester, and 150 (34.4%) from 3rd trimester. As the data were non-normal, the 2.5th, 50th, and 97.5th percentiles were calculated to express each group's results. Trimester specific range of TSH 0.168-4.294, 0.258-4.584 and 0.341-4.625 mIU/mL, FT31.857-4.408, 1.958-4.621 and 2.025-4.821 pmol/L and FT4 8.815-18.006, 8.306-17.341 and 7.402-17.292 pmol/L. Conclusion In this study, we established a trimester-specific reference range for our local population's thyroid function test. The results of this study have complemented the results of previous studies.

scholarly journals Reference Intervals for Serum Thyroid-Stimulating Hormone Based on a Recent Nationwide Cross-Sectional Study and Meta-Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Xichang Wang ◽  
Yongze Li ◽  
Xiaodan Zhai ◽  
Haoyu Wang ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Reference Population ◽  
Cross Sectional Study ◽  
Reference Intervals ◽  
Thyroid Stimulating Hormone ◽  
Primary Data ◽  
Sectional Study ◽  
Cross Sectional ◽  
Iodine Status ◽  
Disease Free

ObjectiveThe aim of our study was to compare the reference intervals (RIs) [median (2.5th-97.5th percentiles)] for thyroid-stimulating hormone (TSH) between subgroups stratified by ethnicity and iodine status in a global context.Design and MethodsPrimary data were derived from a recently published cross-sectional study in mainland China. Secondary data were obtained from online databases. The RIs for TSH were calculated in the reference population according to the National Academy of Clinical Biochemistry (NACB) standard and in the disease-free population. A meta-analysis of ethnicity- and iodine status-specific TSH RIs was performed.ResultsThe primary data showed that the TSH RI (mU/L) in the disease-free population was 2.33 (0.67, 7.87), which is wider than the published RI [2.28 (0.74, 7.04)] in the reference population. The meta-analysis showed that whether in the reference or disease-free population, the RIs in Yellows were much higher than those in Caucasians. In the reference population, the median and 2.5th percentile in the iodine-sufficient subgroup were both lower than the iodine-deficient or more-than-adequate subgroup, while the 97.5th percentile showed a positive trend with increasing sufficiency of iodine. However, in the disease-free population, the iodine-sufficient subgroup had a lower median and 97.5th percentile but higher 2.5th percentile than the iodine-deficient subgroup.ConclusionYellows have a higher TSH RI than Caucasians. In the reference population, both the median and 2.5th percentile TSH in the iodine-sufficient population were the lowest among the different iodine status subgroups, while the 97.5th percentile of TSH showed an upward trend with increasing iodine sufficiency.

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