Longitudinal trajectories of gestational thyroid function: A new approach to better understand changes in thyroid function
Pop,Victor Broeren,Maarten Wijnen,Hennie Endendijk,Joyce van Baar,Anneloes Wiersinga,Wilmar Williams,Graham R.
Pop,Victor
Broeren,Maarten
Wijnen,Hennie
Endendijk,Joyce
van Baar,Anneloes
Wiersinga,Wilmar
Williams,Graham R.
Abstract
Context: Most studies of thyroid function changes during pregnancy use a cross-sectional design comparing means between groups rather than similarities within groups. Objective: Latent class growth analysis (LCGA) is a novel approach to investigate longitudinal changes that provide dynamic understanding of the relationship between thyroid status and advancing pregnancy. Design: Prospective observational study with repeated assessments. Setting: General community. Patients: Eleven hundred healthy women were included at 12 weeks' gestation. Main Outcome Measures: The existence of both free T4 (fT4) and TSH trajectories throughout pregnancy determined by LCGA. Results: LCGA revealed three trajectory classes. Class 1 (n = 1019; 92.4%), a low increasing TSH reference group <had a gradual increase in TSH throughout gestation (from 1.1 to 1.3 IU/L). Class 2 (n = 30; 2.8%), a high increasing TSH grouP <displayed the largest increase in TSH (from 1.9 to 3.3 IU/L). Class 3 (n = 51; 4.6%), a decreasing TSH grouP <had the largest fall in TSH (from 3.2 to 2.4 IU/L). Subclinical hypothyroidism at 12 weeks occurred in up to 60% of class 3 women and was accompanied by elevated thyroid peroxidase antibodies (TPO-Ab) titers (50%) and a parental history of thyroid dysfunction (23%). In class 2, 70% of women were nulliparous compared with 46% in class 1 and 49% in class 3. Conclusions: LCGA revealed distinct trajectories of longitudinal changes in fT4 and TSH levels during pregnancy in 7.4% of women. These trajectories were correlated with parity and TPO-Ab status and followed patterns that might reflect differences in pregnancy-specific immune tolerance between nulliparous and multiparous women.
Description
Date
2018
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Research Projects
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Keywords
REGULATORY T-CELLS, IRON-DEFICIENCY, EARLY-PREGNANCY, GENERATION-R, FETAL SEX, MANAGEMENT, DISEASE, GROWTH, ASSOCIATION, POSTPARTUM
Citation
Pop, V, Broeren, M, Wijnen, H, Endendijk, J, van Baar, A, Wiersinga, W & Williams, G R 2018, 'Longitudinal trajectories of gestational thyroid function : A new approach to better understand changes in thyroid function', Journal of Clinical Endocrinology and Metabolism, vol. 103, no. 8, pp. 2889-2900. https://doi.org/10.1210/jc.2017-02556