Gestational age-specific reference intervals for 15 biochemical measurands during normal pregnancy in China

2017 ◽  
Vol 55 (4) ◽  
pp. 446-452 ◽  
Author(s):  
Yanpeng Dai ◽  
Junjie Liu ◽  
Enwu Yuan ◽  
Yushan Li ◽  
Quanxian Wang ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Gestational Age ◽  
Parametric Method ◽  
First Trimester ◽  
Normal Pregnancy ◽  
Reference Intervals ◽  
Specific Reference ◽  
Gamma Glutamyl Transpeptidase ◽  
Cross Sectional ◽  
Laboratory Results

Aims Physiological changes that occur during pregnancy can influence biochemical parameters. Therefore, using reference intervals based on specimens from non-pregnant women to interpret laboratory results during pregnancy may be inappropriate. This study aimed to establish the essential reference intervals for a range of analytes during pregnancy. Methods A cross-sectional study was performed in 13,656 healthy pregnant and 2634 non-pregnant women. Fifteen biochemical measurands relating to renal and hepatic function were analysed using an Olympus AU5400 analyzer (Olympus, Tokyo, Japan). All the laboratory results were checked for outliers using Dixon’s test. Reference intervals were established using a non-parametric method. Results Alanine aminotransferase, aspartate aminotransferase, albumin, cholinesterase, creatinine, direct bilirubin, gamma-glutamyl transpeptidase, total bilirubin, total bile acid and total protein showed a decrease during the whole gestational period, while alkaline phosphatase and uric acid increased. Urea nitrogen, β2-microglobulin and cystatin-C fell significantly during the first trimester and then remained relatively stable until third trimester. Reference intervals of all the measurands during normal pregnancy have been established. Conclusions The reference intervals established here can be adopted in other clinical laboratories after appropriate validation. We verified the importance, for some measurands, of partitioning by gestational age when establishing reference intervals during pregnancy.

Evaluation of Thyroid Function in Pregnant Women Using Automated Immunoassays

2021 ◽  
Author(s):  
K Aaron Geno ◽  
Matthew S Reed ◽  
Mark A Cervinski ◽  
Robert D Nerenz
Keyword(s):  
Pregnant Women ◽  
Equilibrium Dialysis ◽  
Reference Interval ◽  
First Trimester ◽  
Reference Intervals ◽  
Free Thyroxine ◽  
Specific Reference ◽  
Childbearing Age ◽  
Thyroid Autoantibody ◽  
The Impact

Abstract Introduction Automated free thyroxine (FT4) immunoassays are widely available, but professional guidelines discourage their use in pregnant women due to theoretical under-recoveries attributed to increased thyroid hormone binding capacity and instead advocate the use of total T4 (TT4) or free thyroxine index (FTI). The impact of this recommendation on the classification of thyroid status in apparently euthyroid pregnant patients was evaluated. Methods After excluding specimens with thyroid autoantibody concentrations above reference limits, thyroid-stimulating hormone (TSH), FT4, TT4, and T-uptake were measured on the Roche Cobas® platform in remnant clinical specimens from at least 147 nonpregnant women of childbearing age and pregnant women at each trimester. Split-sample comparisons of FT4 as measured by the Cobas and equilibrium dialysis were performed. Results FT4 decreased with advancing gestational age by both immunoassay and equilibrium dialysis. TSH declined during the first trimester, remained constant in the second, and increased throughout the third, peaking just before delivery. Interpretation of TT4 concentrations using 1.5-times the nonpregnant reference interval classified 13.6% of first trimester specimens below the lower reference limit despite TSH concentrations within trimester-specific reference intervals. Five FTI results from 480 pregnant individuals (about 1.0%) fell outside the manufacturer’s reference interval. Conclusions Indirect FT4 immunoassay results interpreted in the context of trimester-specific reference intervals provide a practical and viable alternative to TT4 or FTI. Declining FT4 and increasing TSH concentrations near term suggest that declining FT4 is not an analytical artifact but represents a true physiological change in preparation for labor and delivery.

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 Early pregnancy reference intervals; 29 serum analytes from 4 to 12 weeks’ gestation in naturally conceived and uncomplicated pregnancies resulting in live births

2019 ◽  
Vol 57 (12) ◽  
pp. 1956-1967 ◽  
Author(s):  
Jesper Friis Petersen ◽  
Lennart J. Friis-Hansen ◽  
Andreas Kryger Jensen ◽  
Anders Nyboe Andersen ◽  
Ellen C.L. Løkkegaard
Keyword(s):  
Pregnant Women ◽  
Early Pregnancy ◽  
Clinical Chemistry ◽  
Clinical Care ◽  
Local Population ◽  
First Trimester ◽  
Reference Intervals ◽  
Specific Reference ◽  
Cancer Antigen 125 ◽  
Serum Samples

Abstract Background Pregnancy introduces major physiological changes that also alter biochemical analytes. Maternal and perinatal health can be optimized by early intervention and therefore, pregnancy-specific reference intervals (RIs) for the local population are warranted. While the second and third trimester-specific changes are well described, the first trimester is less well characterized. We therefore wanted to facilitate early detection of abnormalities by generating first trimester reference values for 29 common analytes. Methods In a prospective early pregnancy (PEP) cohort (2016–2017), 203 pregnant women were recruited from 4 to 8 weeks’ gestation. Consecutive blood samples were drawn every 2 weeks until an ongoing second trimester pregnancy (n = 164) or a miscarriage (n = 39) occurred. After exclusion of women with complicated pregnancies or deliveries (n = 42), 122 women were included. The serum samples collected at <6, 6–8, 8–10, 10–12 and >12 weeks’ gestation were analyzed for 29 common analytes. Subsequently the RIs were calculated according to the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommendations (2.5–97.5th percentiles) and compared with the conventional RIs for non-pregnant women. Results Human chorionic gonadotropin (hCG), progesterone (P4), estradiol (E2), pregnancy-associated plasma protein A (PAPP-A), cancer antigen 125 (CA125), thyroid stimulating hormone (TSH), creatinine (CREA) and albumin (ALB) showed an early pregnancy-dependent change compared with conventional limits. For ALB the change was seen at 5.5 weeks’ gestation. Conclusions We report gestational age-specific RIs available from the early part of the first trimester applicable to everyday clinical care of pregnant women. Well-known alterations of RIs seen in later trimesters are also observed in the first.

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

Gestation specific reference intervals for thyroid function tests in pregnancy

2016 ◽  
Vol 54 (8) ◽  
Author(s):  
Süleyman Akarsu ◽  
Filiz Akbiyik ◽  
Eda Karaismailoglu ◽  
Zeliha Gunnur Dikmen
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
First Trimester ◽  
Reference Intervals ◽  
Specific Reference ◽  
Thyroid Function Tests ◽  
Second Trimester ◽  
Third Trimester ◽  
The Third ◽  
Function Tests

AbstractThyroid function tests are frequently assessed during pregnancy to evaluate thyroid dysfunction or to monitor pre-existing thyroid disease. However, using non-pregnant reference intervals can lead to misclassification. International guidelines recommended that institutions should calculate their own pregnancy-specific reference intervals for free thyroxine (FT4), free triiodothyronine (FT3) and thyroid-stimulating hormone (TSH). The objective of this study is to establish gestation-specific reference intervals (GRIs) for thyroid function tests in pregnant Turkish women and to compare these with the age-matched non-pregnant women.Serum samples were collected from 220 non-pregnant women (age: 18–48), and 2460 pregnant women (age: 18–45) with 945 (39%) in the first trimester, 1120 (45%) in the second trimester, and 395 (16%) in the third trimester. TSH, FT4 and FT3 were measured using the Abbott Architect i2000SR analyzer.GRIs of TSH, FT4 and FT3 for first trimester pregnancies were 0.49–2.33 mIU/L, 10.30–18.11 pmol/L and 3.80–5.81 pmol/L, respectively. GRIs for second trimester pregnancies were 0.51–3.44 mIU/L, 10.30–18.15 pmol/L and 3.69–5.90 pmol/L. GRIs for third trimester pregnancies were 0.58–4.31 mIU/L, 10.30–17.89 pmol/L and 3.67–5.81 pmol/L. GRIs for TSH, FT4 and FT3 were different from non-pregnant normal reference intervals.TSH levels showed an increasing trend from the first trimester to the third trimester, whereas both FT4 and FT3 levels were uniform throughout gestation. GRIs may help in the diagnosis and appropriate management of thyroid dysfunction during pregnancy which will prevent both maternal and fetal complications.

scholarly journals Trimester-Specific Reference Ranges for Saturated, Monounsaturated and Polyunsaturated Fatty Acids in Serum of Pregnant Women: A Cohort Study from the ECLIPSES Group

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 4037
Author(s):  
Carla Martín-Grau ◽  
Ramón Deulofeu ◽  
Nuria Serrat Orus ◽  
Victoria Arija ◽  
Keyword(s):  
Fatty Acids ◽  
Pregnant Women ◽  
Large Population ◽  
First Trimester ◽  
Reference Intervals ◽  
Gas Chromatography Mass Spectrometry ◽  
Specific Reference ◽  
Reference Ranges ◽  
Maternal Factors ◽  
Developed Country

In the course of pregnancy, increasing importance is being placed on maintaining optimal fatty acid (FA) levels and particularly n-3 PUFAs to ensure correct fetal development. However, reference ranges for FA have been reported in only a few studies. Our objective is to provide quantitative reference intervals for SFAs, MUFAs, and PUFAs (n-6 and n-3) in a large population of healthy pregnant women from a developed country. A prospective study of pregnant women (n = 479) was conducted from the first trimester (T1) to the third trimester (T3). A total of 11 fatty acids were analyzed in serum by gas chromatography mass spectrometry and were expressed as absolute (µmol/L) and relative (percentage of total FA) concentration units. Serum concentrations of SFAs, MUFAs, n-6 PUFAs, n-3 PUFAs, various FA ratios, and the EFA index were determined. The reference intervals (2.5/97.5 percentiles) in absolute values from T1 ranged from 1884.32 to 8802.81 µmol/L for SFAs, from 959.91 to 2979.46 µmol/L for MUFAs, from 2325.77 to 7735.74 µmol/L for n-6 PUFAs, and from 129.01 to 495.58 µmol/L for n-3 PUFAs. These intervals mainly include the values of other studies from European populations. However, reference ranges vary according to some maternal factors. The FA levels proposed, obtained from a large sample of pregnant women, will be a useful tool for assessing the degree of adequacy of FAs in pregnant women and will help to carry out dietary interventions based on certain maternal factors.

scholarly journals Evaluation of maternal thyroid function during pregnancy: the importance of using gestational age-specific reference intervals

2007 ◽  
Vol 157 (4) ◽  
pp. 509-514 ◽  
Author(s):  
Rt Stricker ◽  
M Echenard ◽  
R Eberhart ◽  
M-C Chevailler ◽  
V Perez ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Gestational Age ◽  
Thyroid Disease ◽  
Thyroid Dysfunction ◽  
Reference Intervals ◽  
Specific Reference ◽  
Thyroid Function Tests ◽  
Laboratory Evidence ◽  
Maternal Thyroid

Background: Maternal thyroid dysfunction has been associated with a variety of adverse pregnancy outcomes. Laboratory measurement of thyroid function plays an important role in the assessment of maternal thyroid health. However, occult thyroid disease and physiologic changes associated with pregnancy can complicate interpretation of maternal thyroid function tests (TFTs). Objective and methods: To 1) establish the prevalence of laboratory evidence for autoimmune thyroid disease (AITD) in pregnant women; 2) establish gestational age-specific reference intervals for TFTs in women without AITD; and 3) examine the influence of reference intervals on the interpretation of TFT in pregnant women. Serum samples were collected from 2272 pregnant women, and TFT performed. Gestational age-specific reference intervals were determined in women without AITD, and then compared with the non-pregnant assay-specific reference intervals for interpretation of testing results. Results: Thyroid peroxidase antibodies (TPO-Ab) and thyroglobulin antibodies (Tg-Ab) were positive in 10.4 and 15.7% of women respectively. TPO-Ab level was related to maternal age, but TPO-Ab status, Tg-Ab status, and Tg-Ab level were not. Women with TSH > 3.0 mIU/l were significantly more likely to be TPO-Ab positive. Gestational age-specific reference intervals for TFT were significantly different from non-pregnant normal reference intervals. Interpretation of TFT in pregnant women using non-pregnant reference intervals could potentially result in misclassification of a significant percentage of results (range: 5.6–18.3%). Conclusion: Laboratory evidence for thyroid dysfunction was common in this population of pregnant women. Accurate classification of TFT in pregnant women requires the use of gestational age-specific reference intervals.

scholarly journals Lipid Profile of Healthy Women During Normal Pregnancy

2009 ◽  
Vol 28 (3) ◽  
pp. 152-160 ◽  
Author(s):  
Margarita Diareme ◽  
Petros Karkalousos ◽  
Georgos Theodoropoulos ◽  
Stefanos Strouzas ◽  
Nikos Lazanas
Keyword(s):  
Pregnant Women ◽  
Lipid Profile ◽  
Gestational Age ◽  
First Trimester ◽  
Normal Pregnancy ◽  
Second Trimester ◽  
Third Trimester ◽  
Predisposing Factor ◽  
Healthy Women ◽  
C 30

Lipid Profile of Healthy Women During Normal PregnancyThe four basic lipid indexes (Chol, Trig, HDL-C and LDL-C) increase during pregnancy, following different rates of increase. Among the four analytes triglycerides show the largest increase and HDL-C the smallest. All analyte values are raised during the 40 weeks of pregnancy, except HDL-C which is stabilized during the second trimester. After delivery the values decrease, except LDL-C which remains steady (for some weeks) before starting to fall following the others. In this study the relations between the four lipid indexes and some predisposing factors (age, gestational age, nationality, body mass index, profession, smoking and diabetes during pregnancy) were investigated. The sample consisted of 413 pregnant women, mainly Greeks and Albanians. After regression analysis it was proved that the only common predisposing factor was the gestational age. Triglycerides and total cholesterol are also influenced by the women's age. The lipid indexes showed no important difference between the pregnant women in the first trimester and the non-pregnant women. On the contrary, there was a statistical difference between the pregnant women in the second and third trimester and between them and the women in the first trimester. The percentages of increase between first and second trimester were: Chol: 38%, Trig: 115%, HDL-C: 30%, LDL-C: 33%. The percentages of increase between first and third trimester were: Chol: 65%, Trig: 208%, HDL-C: 26%, LDLC: 64%.

scholarly journals MMP-9 Level Comparation between Spontaneous Abortion and Normal Pregnancy

2012 ◽  
Vol 4 (3) ◽  
pp. 174
Author(s):  
Aloysius Suryawan ◽  
Johanes C Mose ◽  
Budi Handono
Keyword(s):  
Pregnant Women ◽  
Spontaneous Abortion ◽  
Fetal Death ◽  
Embryo Implantation ◽  
Obstetric Care ◽  
First Trimester ◽  
Normal Pregnancy ◽  
Cross Sectional Study ◽  
Cross Sectional

BACKGROUND: Abortion remains a problem in the obstetric care as it is one of the causes of maternal and fetal death. Bleeding or miscarriage threat in the first trimester comprises 20% to 25% of all pregnant women, and 50% of them will end as spontaneous abortion. The major cause of maternal death in abortion is hemorrhage. Some recent studies have indicated that MMP-9 is important in the process of embryo implantation into the endometrium and spontaneous abortion occurs when there is an overwhelming increase of MMP-9. This data indicate the importance of a further research to elucidate the role of MMP-9 in spontaneous abortion.METHODS: This was a cross sectional study, included 70 pregnant women with gestational age <20 weeks who came for examination and treatment at the Department of Obstetrics and Gynecology, Medical Faculty of Padjadjaran University/Hasan Sadikin Hospital, Bandung. RESULTS: There were differences in the MMP-9 levels in spontaneous abortion compared to normal pregnancy and MMP-9 had a cut-off point >1221.7 with the sensitivity of 48.6% specificity of 80%, and accuracy of 60.9%.SUMMARY: The MMP-9 level in spontaneous abortion was higher than in normal pregnancy.KEYWORDS: MMP-9, spontaneous abortion, normal pregnancy

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