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Helena Strevens - One of the best experts on this subject based on the ideXlab platform.
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temporal changes of the plasma levels of cystatin c beta trace protein beta 2 microglobulin urate and creatinine during pregnancy indicate continuous alterations in the renal filtration process
Scandinavian Journal of Clinical & Laboratory Investigation, 2007Co-Authors: Karl Kristensen, Dag Wideswensson, Soren Blirupjensen, Veronica Lindstrom, Helena StrevensAbstract:Objective. To determine the plasma levels of the renal functional markers creatinine, urate, cystatin C, β2‐microglobulin and β‐trace protein in samples from the first, second, early third and late third Trimesters of 398 healthy women with uncomplicated singleton pregnancies. Material and methods. Plasma samples from 58 healthy non‐pregnant women served as controls. The creatinine levels were significantly lower at all time‐points in pregnancy, whereas the urate levels were lower during the first and second Trimesters but increased in the late third Trimester. The cystatin C, β2‐microglobulin and β‐trace protein levels displayed similar changes with increased levels in the third Trimester but unaltered levels during the first and second Trimesters. Results. The results indicate an increased filtration of low‐molecular weight molecules during pregnancy, particularly during the first and second Trimesters, whereas filtration of 10–30 kDa molecules is decreased in the third but unaltered in the first and se...
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temporal changes of the plasma levels of cystatin c beta trace protein beta2 microglobulin urate and creatinine during pregnancy indicate continuous alterations in the renal filtration process
Scandinavian Journal of Clinical & Laboratory Investigation, 2007Co-Authors: Karl Kristensen, Dag Wideswensson, Soren Blirupjensen, Veronica Lindstrom, C Schmidt, Anders Grubb, Helena StrevensAbstract:OBJECTIVE: To determine the plasma levels of the renal functional markers creatinine, urate, cystatin C, beta2-microglobulin and beta-trace protein in samples from the first, second, early third and late third Trimesters of 398 healthy women with uncomplicated singleton pregnancies. MATERIAL AND METHODS: Plasma samples from 58 healthy non-pregnant women served as controls. The creatinine levels were significantly lower at all time-points in pregnancy, whereas the urate levels were lower during the first and second Trimesters but increased in the late third Trimester. The cystatin C, beta2-microglobulin and beta-trace protein levels displayed similar changes with increased levels in the third Trimester but unaltered levels during the first and second Trimesters. RESULTS: The results indicate an increased filtration of low-molecular weight molecules during pregnancy, particularly during the first and second Trimesters, whereas filtration of 10-30 kDa molecules is decreased in the third but unaltered in the first and second Trimesters. The levels of albumin and alph2-macroglobulin were measured in the same samples. CONCLUSIONS: The albumin levels decreased in the second and third Trimesters, whereas the levels of chi2-macroglobulin were unchanged, which is compatible with a virtually unaltered transfer of chi2-macroglobulin between the intra- and extravascular space during pregnancy and a significantly increased extravascular fraction of albumin.
James E Haddow - One of the best experts on this subject based on the ideXlab platform.
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Free Thyroxine During Early Pregnancy and Risk for Gestational Diabetes
2016Co-Authors: James E Haddow, Glenn E Palomaki, Fergal D Malone, Wendy Y. Craig, Louis M. Neveux, Geralyn Lambert-messerlian, Mary E. D’altonAbstract:Several studies have now reported associations between gestational diabetes mellitus (GDM) and low free thyroxine (fT4) during the second and third Trimesters, but not in the first Trimester. The present study further examines relationships between low fT4, maternal weight, and GDM among women in the FaSTER (First and Second Trimester Evaluation of Risk) trial, in an effort to determine the extent to which thyroid hormones might contribute to causality. The FaSTER cohort includes 9351 singleton, euthyroid women; 272 of these women were subsequently classified as having GDM. Thyrotropin (TSH), fT4, and thyroid antibodies were measured at 11–14 weeks’ gestation (first Trimester) and 15–18.9 weeks’ gestation (second Trimester). An earlier report of this cohort documented an inverse relationship between fT4 in the second Trimester and maternal weight. In the current analysis, women with GDM were significantly older (32 vs. 28 years) and weighed more (75 vs. 64.5 kg). Maternal weight and age (but not TSH) were significantly associated univariately with fT4 (dependent variable), in the order listed. Second Trimester fT4 odds ratios (OR) for GDM were 2.06 [95% CI 1.37–3.09] (unadjusted); and 1.89 [95% CI 1.26–2.84] (adjusted). First Trimester odds ratios were not significant: OR 1.45 [95%CI 0.97–2.16] (unadjusted) and 1.11 [95% CI 0.74–1.62] (adjusted). The second Trimester fT4/GDM relationship thus appeared to strengthen as gestation progressed. In FaSTER, high maternal weight was associated with both low fT4 and a higher GDM rate in the second Trimester. Peripheral deiodinase activity is known to increase with high caloric intake (represented by high weight). We speculate that weight-related low fT4 (the metabolically inactive prohormone) is a marker for deiodinase activity, serving as a substrate for conversion of fT4 to free triiodothyronine (fT3), the active hormone responsible for glucose-related metabolic activity.
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first and second Trimester thyroid hormone reference data in pregnant women a faster first and second Trimester evaluation of risk for aneuploidy research consortium study
American Journal of Obstetrics and Gynecology, 2008Co-Authors: Geralyn Lambertmesserlian, Flint T Porter, James E Haddow, Glenn E Palomaki, Monica R Mcclain, Jacob A Canick, Jane Clearygoldman, Fergal D Malone, David A NybergAbstract:Objective The purpose of this study was to calculate first and second Trimester reference ranges and within-woman correlations for TSH, free T4, and thyroid antibodies. Study Design TSH, free T4, and thyroid antibodies were measured in paired sera from 9562 women in the FaSTER trial of Down syndrome screening. Results The median first Trimester TSH (1.05 mIU/L) is lower than the second (1.23 mIU/L); and 98th centile is higher (4.15 vs 3.77 mIU/L). Within-woman paired TSH correlations are moderately strong ( r 2 = 0.64). Among women with first Trimester TSH values above the 98th centile, second Trimester values are over the 95th centile in 68%. Median first Trimester free T4 values (1.10 ng/dL) are higher than second (1.01 ng/dL). Paired free T4 measurements correlate weakly ( r 2 = 0.23). Among women with first Trimester free T4 values below the 2nd centile, second Trimester values are below the 5th centile in 32%. Antibody measurements correlate strongly between Trimesters (thyroperoxidase r 2 = 0.79, thyroglobulin r 2 = 0.83). Conclusion TSH and free T4 measurements require gestation-specific reference ranges.
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first and second Trimester thyroid hormone reference data in pregnant women a faster first and second Trimester evaluation of risk for aneuploidy research consortium study
American Journal of Obstetrics and Gynecology, 2008Co-Authors: Geralyn Lambertmesserlian, Flint T Porter, James E Haddow, Glenn E Palomaki, Monica R Mcclain, Jacob A Canick, Jane Clearygoldman, Fergal D Malone, David A NybergAbstract:Objective The purpose of this study was to calculate first and second Trimester reference ranges and within-woman correlations for TSH, free T4, and thyroid antibodies. Study Design TSH, free T4, and thyroid antibodies were measured in paired sera from 9562 women in the FaSTER trial of Down syndrome screening. Results The median first Trimester TSH (1.05 mIU/L) is lower than the second (1.23 mIU/L); and 98th centile is higher (4.15 vs 3.77 mIU/L). Within-woman paired TSH correlations are moderately strong ( r 2 = 0.64). Among women with first Trimester TSH values above the 98th centile, second Trimester values are over the 95th centile in 68%. Median first Trimester free T4 values (1.10 ng/dL) are higher than second (1.01 ng/dL). Paired free T4 measurements correlate weakly ( r 2 = 0.23). Among women with first Trimester free T4 values below the 2nd centile, second Trimester values are below the 5th centile in 32%. Antibody measurements correlate strongly between Trimesters (thyroperoxidase r 2 = 0.79, thyroglobulin r 2 = 0.83). Conclusion TSH and free T4 measurements require gestation-specific reference ranges.
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the reference range and within person variability of thyroid stimulating hormone during the first and second Trimesters of pregnancy
Journal of Medical Screening, 2004Co-Authors: James E Haddow, G J Knight, Glenn E Palomaki, Andrea PulkkinenAbstract:Objective: To further explore first and second Trimester reference ranges for thyroid stimulating hormone (TSH) and examine within-person variability of TSH and thyroid peroxidase (TPO) antibody.Setting: Women coming for routine prenatal care in early pregnancy agreed to participate in a trial of integrated serum screening for Down's syndrome. Two serum samples were obtained from each woman, one each in the first and second Trimesters. These samples were also available for TSH and TPO measurements in the present study.Methods: TSH and TPO antibody measurements were performed in 1126 women with ultrasound-dated pregnancies who provided serum samples in both Trimesters. TSH reference ranges were established for the entire cohort and for the antibody-negative subgroup. Within-person variability of TSH measurements between Trimesters was examined.Results: Median TSH values are lower in the first Trimester than in the second (1.00 versus 1.29 mIU/l), but 98th centile values are higher (5.20 versus 4.18 mIU/l)....
Fergal D Malone - One of the best experts on this subject based on the ideXlab platform.
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Free Thyroxine During Early Pregnancy and Risk for Gestational Diabetes
2016Co-Authors: James E Haddow, Glenn E Palomaki, Fergal D Malone, Wendy Y. Craig, Louis M. Neveux, Geralyn Lambert-messerlian, Mary E. D’altonAbstract:Several studies have now reported associations between gestational diabetes mellitus (GDM) and low free thyroxine (fT4) during the second and third Trimesters, but not in the first Trimester. The present study further examines relationships between low fT4, maternal weight, and GDM among women in the FaSTER (First and Second Trimester Evaluation of Risk) trial, in an effort to determine the extent to which thyroid hormones might contribute to causality. The FaSTER cohort includes 9351 singleton, euthyroid women; 272 of these women were subsequently classified as having GDM. Thyrotropin (TSH), fT4, and thyroid antibodies were measured at 11–14 weeks’ gestation (first Trimester) and 15–18.9 weeks’ gestation (second Trimester). An earlier report of this cohort documented an inverse relationship between fT4 in the second Trimester and maternal weight. In the current analysis, women with GDM were significantly older (32 vs. 28 years) and weighed more (75 vs. 64.5 kg). Maternal weight and age (but not TSH) were significantly associated univariately with fT4 (dependent variable), in the order listed. Second Trimester fT4 odds ratios (OR) for GDM were 2.06 [95% CI 1.37–3.09] (unadjusted); and 1.89 [95% CI 1.26–2.84] (adjusted). First Trimester odds ratios were not significant: OR 1.45 [95%CI 0.97–2.16] (unadjusted) and 1.11 [95% CI 0.74–1.62] (adjusted). The second Trimester fT4/GDM relationship thus appeared to strengthen as gestation progressed. In FaSTER, high maternal weight was associated with both low fT4 and a higher GDM rate in the second Trimester. Peripheral deiodinase activity is known to increase with high caloric intake (represented by high weight). We speculate that weight-related low fT4 (the metabolically inactive prohormone) is a marker for deiodinase activity, serving as a substrate for conversion of fT4 to free triiodothyronine (fT3), the active hormone responsible for glucose-related metabolic activity.
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first and second Trimester thyroid hormone reference data in pregnant women a faster first and second Trimester evaluation of risk for aneuploidy research consortium study
American Journal of Obstetrics and Gynecology, 2008Co-Authors: Geralyn Lambertmesserlian, Flint T Porter, James E Haddow, Glenn E Palomaki, Monica R Mcclain, Jacob A Canick, Jane Clearygoldman, Fergal D Malone, David A NybergAbstract:Objective The purpose of this study was to calculate first and second Trimester reference ranges and within-woman correlations for TSH, free T4, and thyroid antibodies. Study Design TSH, free T4, and thyroid antibodies were measured in paired sera from 9562 women in the FaSTER trial of Down syndrome screening. Results The median first Trimester TSH (1.05 mIU/L) is lower than the second (1.23 mIU/L); and 98th centile is higher (4.15 vs 3.77 mIU/L). Within-woman paired TSH correlations are moderately strong ( r 2 = 0.64). Among women with first Trimester TSH values above the 98th centile, second Trimester values are over the 95th centile in 68%. Median first Trimester free T4 values (1.10 ng/dL) are higher than second (1.01 ng/dL). Paired free T4 measurements correlate weakly ( r 2 = 0.23). Among women with first Trimester free T4 values below the 2nd centile, second Trimester values are below the 5th centile in 32%. Antibody measurements correlate strongly between Trimesters (thyroperoxidase r 2 = 0.79, thyroglobulin r 2 = 0.83). Conclusion TSH and free T4 measurements require gestation-specific reference ranges.
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first and second Trimester thyroid hormone reference data in pregnant women a faster first and second Trimester evaluation of risk for aneuploidy research consortium study
American Journal of Obstetrics and Gynecology, 2008Co-Authors: Geralyn Lambertmesserlian, Flint T Porter, James E Haddow, Glenn E Palomaki, Monica R Mcclain, Jacob A Canick, Jane Clearygoldman, Fergal D Malone, David A NybergAbstract:Objective The purpose of this study was to calculate first and second Trimester reference ranges and within-woman correlations for TSH, free T4, and thyroid antibodies. Study Design TSH, free T4, and thyroid antibodies were measured in paired sera from 9562 women in the FaSTER trial of Down syndrome screening. Results The median first Trimester TSH (1.05 mIU/L) is lower than the second (1.23 mIU/L); and 98th centile is higher (4.15 vs 3.77 mIU/L). Within-woman paired TSH correlations are moderately strong ( r 2 = 0.64). Among women with first Trimester TSH values above the 98th centile, second Trimester values are over the 95th centile in 68%. Median first Trimester free T4 values (1.10 ng/dL) are higher than second (1.01 ng/dL). Paired free T4 measurements correlate weakly ( r 2 = 0.23). Among women with first Trimester free T4 values below the 2nd centile, second Trimester values are below the 5th centile in 32%. Antibody measurements correlate strongly between Trimesters (thyroperoxidase r 2 = 0.79, thyroglobulin r 2 = 0.83). Conclusion TSH and free T4 measurements require gestation-specific reference ranges.
David A Nyberg - One of the best experts on this subject based on the ideXlab platform.
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first and second Trimester thyroid hormone reference data in pregnant women a faster first and second Trimester evaluation of risk for aneuploidy research consortium study
American Journal of Obstetrics and Gynecology, 2008Co-Authors: Geralyn Lambertmesserlian, Flint T Porter, James E Haddow, Glenn E Palomaki, Monica R Mcclain, Jacob A Canick, Jane Clearygoldman, Fergal D Malone, David A NybergAbstract:Objective The purpose of this study was to calculate first and second Trimester reference ranges and within-woman correlations for TSH, free T4, and thyroid antibodies. Study Design TSH, free T4, and thyroid antibodies were measured in paired sera from 9562 women in the FaSTER trial of Down syndrome screening. Results The median first Trimester TSH (1.05 mIU/L) is lower than the second (1.23 mIU/L); and 98th centile is higher (4.15 vs 3.77 mIU/L). Within-woman paired TSH correlations are moderately strong ( r 2 = 0.64). Among women with first Trimester TSH values above the 98th centile, second Trimester values are over the 95th centile in 68%. Median first Trimester free T4 values (1.10 ng/dL) are higher than second (1.01 ng/dL). Paired free T4 measurements correlate weakly ( r 2 = 0.23). Among women with first Trimester free T4 values below the 2nd centile, second Trimester values are below the 5th centile in 32%. Antibody measurements correlate strongly between Trimesters (thyroperoxidase r 2 = 0.79, thyroglobulin r 2 = 0.83). Conclusion TSH and free T4 measurements require gestation-specific reference ranges.
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first and second Trimester thyroid hormone reference data in pregnant women a faster first and second Trimester evaluation of risk for aneuploidy research consortium study
American Journal of Obstetrics and Gynecology, 2008Co-Authors: Geralyn Lambertmesserlian, Flint T Porter, James E Haddow, Glenn E Palomaki, Monica R Mcclain, Jacob A Canick, Jane Clearygoldman, Fergal D Malone, David A NybergAbstract:Objective The purpose of this study was to calculate first and second Trimester reference ranges and within-woman correlations for TSH, free T4, and thyroid antibodies. Study Design TSH, free T4, and thyroid antibodies were measured in paired sera from 9562 women in the FaSTER trial of Down syndrome screening. Results The median first Trimester TSH (1.05 mIU/L) is lower than the second (1.23 mIU/L); and 98th centile is higher (4.15 vs 3.77 mIU/L). Within-woman paired TSH correlations are moderately strong ( r 2 = 0.64). Among women with first Trimester TSH values above the 98th centile, second Trimester values are over the 95th centile in 68%. Median first Trimester free T4 values (1.10 ng/dL) are higher than second (1.01 ng/dL). Paired free T4 measurements correlate weakly ( r 2 = 0.23). Among women with first Trimester free T4 values below the 2nd centile, second Trimester values are below the 5th centile in 32%. Antibody measurements correlate strongly between Trimesters (thyroperoxidase r 2 = 0.79, thyroglobulin r 2 = 0.83). Conclusion TSH and free T4 measurements require gestation-specific reference ranges.
Glenn E Palomaki - One of the best experts on this subject based on the ideXlab platform.
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Free Thyroxine During Early Pregnancy and Risk for Gestational Diabetes
2016Co-Authors: James E Haddow, Glenn E Palomaki, Fergal D Malone, Wendy Y. Craig, Louis M. Neveux, Geralyn Lambert-messerlian, Mary E. D’altonAbstract:Several studies have now reported associations between gestational diabetes mellitus (GDM) and low free thyroxine (fT4) during the second and third Trimesters, but not in the first Trimester. The present study further examines relationships between low fT4, maternal weight, and GDM among women in the FaSTER (First and Second Trimester Evaluation of Risk) trial, in an effort to determine the extent to which thyroid hormones might contribute to causality. The FaSTER cohort includes 9351 singleton, euthyroid women; 272 of these women were subsequently classified as having GDM. Thyrotropin (TSH), fT4, and thyroid antibodies were measured at 11–14 weeks’ gestation (first Trimester) and 15–18.9 weeks’ gestation (second Trimester). An earlier report of this cohort documented an inverse relationship between fT4 in the second Trimester and maternal weight. In the current analysis, women with GDM were significantly older (32 vs. 28 years) and weighed more (75 vs. 64.5 kg). Maternal weight and age (but not TSH) were significantly associated univariately with fT4 (dependent variable), in the order listed. Second Trimester fT4 odds ratios (OR) for GDM were 2.06 [95% CI 1.37–3.09] (unadjusted); and 1.89 [95% CI 1.26–2.84] (adjusted). First Trimester odds ratios were not significant: OR 1.45 [95%CI 0.97–2.16] (unadjusted) and 1.11 [95% CI 0.74–1.62] (adjusted). The second Trimester fT4/GDM relationship thus appeared to strengthen as gestation progressed. In FaSTER, high maternal weight was associated with both low fT4 and a higher GDM rate in the second Trimester. Peripheral deiodinase activity is known to increase with high caloric intake (represented by high weight). We speculate that weight-related low fT4 (the metabolically inactive prohormone) is a marker for deiodinase activity, serving as a substrate for conversion of fT4 to free triiodothyronine (fT3), the active hormone responsible for glucose-related metabolic activity.
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first and second Trimester thyroid hormone reference data in pregnant women a faster first and second Trimester evaluation of risk for aneuploidy research consortium study
American Journal of Obstetrics and Gynecology, 2008Co-Authors: Geralyn Lambertmesserlian, Flint T Porter, James E Haddow, Glenn E Palomaki, Monica R Mcclain, Jacob A Canick, Jane Clearygoldman, Fergal D Malone, David A NybergAbstract:Objective The purpose of this study was to calculate first and second Trimester reference ranges and within-woman correlations for TSH, free T4, and thyroid antibodies. Study Design TSH, free T4, and thyroid antibodies were measured in paired sera from 9562 women in the FaSTER trial of Down syndrome screening. Results The median first Trimester TSH (1.05 mIU/L) is lower than the second (1.23 mIU/L); and 98th centile is higher (4.15 vs 3.77 mIU/L). Within-woman paired TSH correlations are moderately strong ( r 2 = 0.64). Among women with first Trimester TSH values above the 98th centile, second Trimester values are over the 95th centile in 68%. Median first Trimester free T4 values (1.10 ng/dL) are higher than second (1.01 ng/dL). Paired free T4 measurements correlate weakly ( r 2 = 0.23). Among women with first Trimester free T4 values below the 2nd centile, second Trimester values are below the 5th centile in 32%. Antibody measurements correlate strongly between Trimesters (thyroperoxidase r 2 = 0.79, thyroglobulin r 2 = 0.83). Conclusion TSH and free T4 measurements require gestation-specific reference ranges.
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first and second Trimester thyroid hormone reference data in pregnant women a faster first and second Trimester evaluation of risk for aneuploidy research consortium study
American Journal of Obstetrics and Gynecology, 2008Co-Authors: Geralyn Lambertmesserlian, Flint T Porter, James E Haddow, Glenn E Palomaki, Monica R Mcclain, Jacob A Canick, Jane Clearygoldman, Fergal D Malone, David A NybergAbstract:Objective The purpose of this study was to calculate first and second Trimester reference ranges and within-woman correlations for TSH, free T4, and thyroid antibodies. Study Design TSH, free T4, and thyroid antibodies were measured in paired sera from 9562 women in the FaSTER trial of Down syndrome screening. Results The median first Trimester TSH (1.05 mIU/L) is lower than the second (1.23 mIU/L); and 98th centile is higher (4.15 vs 3.77 mIU/L). Within-woman paired TSH correlations are moderately strong ( r 2 = 0.64). Among women with first Trimester TSH values above the 98th centile, second Trimester values are over the 95th centile in 68%. Median first Trimester free T4 values (1.10 ng/dL) are higher than second (1.01 ng/dL). Paired free T4 measurements correlate weakly ( r 2 = 0.23). Among women with first Trimester free T4 values below the 2nd centile, second Trimester values are below the 5th centile in 32%. Antibody measurements correlate strongly between Trimesters (thyroperoxidase r 2 = 0.79, thyroglobulin r 2 = 0.83). Conclusion TSH and free T4 measurements require gestation-specific reference ranges.
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the reference range and within person variability of thyroid stimulating hormone during the first and second Trimesters of pregnancy
Journal of Medical Screening, 2004Co-Authors: James E Haddow, G J Knight, Glenn E Palomaki, Andrea PulkkinenAbstract:Objective: To further explore first and second Trimester reference ranges for thyroid stimulating hormone (TSH) and examine within-person variability of TSH and thyroid peroxidase (TPO) antibody.Setting: Women coming for routine prenatal care in early pregnancy agreed to participate in a trial of integrated serum screening for Down's syndrome. Two serum samples were obtained from each woman, one each in the first and second Trimesters. These samples were also available for TSH and TPO measurements in the present study.Methods: TSH and TPO antibody measurements were performed in 1126 women with ultrasound-dated pregnancies who provided serum samples in both Trimesters. TSH reference ranges were established for the entire cohort and for the antibody-negative subgroup. Within-person variability of TSH measurements between Trimesters was examined.Results: Median TSH values are lower in the first Trimester than in the second (1.00 versus 1.29 mIU/l), but 98th centile values are higher (5.20 versus 4.18 mIU/l)....
