Universal screening as a recommendation for thyroid tests in pregnant women
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Department of Endocrinology, Medical University, Lublin, Poland
Terpa, Doctor’s Private Practice, Lublin, Poland
Ann Agric Environ Med. 2011;18(2):375–379
According to recent recommendations, thyroid tests in pregnancy should be performed only in women in risk groups. However, detailed studies indicate that such an approach results in missing hypothyroidism in 30% and hyperthyroidism in 69% of pregnant women. The aim of this study was to compare the effectiveness of diagnosing hypothyroidism in pregnant women by applying universal screening tests, and assessing risk factors. The study was carried out on 270 non-selected women in single pregnancy who underwent screening for hypothyroidism (diagnostic criteria: TSH > 2.5 mIU/L) during their first prenatal visit between the 6 th - 10 th week of gestation. After excluding the patients with pre-gestational hypothyroidism, risk factors for this disorder were assessed in the remaining subjects. A group of 28 patients (10.4% of all subjects) with hypothyroidism was selected for further thyroid tests, while the remaining 242 pregnant women (TSH < 2.5mIU/L) aged 26.3+/-3.59 formed the control group. Twenty subjects (71.4%) were thyroid antibodies-positive, while 8 patients were thyroid antibodies-negative. When analyzing hypothyroidism risk factors, one was found in 10 subjects (35.7%), 2 in 5 subjects (17.8%), whereas, in 13 subjects (46.4%) none were present. Symptoms suggesting thyroid dysfunction were discovered in 8 patients (53.3%), goiter in 5 patients (33.3%), another 5 patients (33.3%) had a positive gynaecological history, and only 2 patients had a positive family history of autoimmune thyroid diseases. During the analysis, it was found that TSH positively correlated with the age of the subjects. In the whole study group, a significant correlation was found between log TSH and hypothyroidism risk factors. Hypothyroidism (TSH > 2.5 mlU/L) was diagnosed in 10.4% of the patients. The primary cause of this pathology was thyroiditis which was diagnosed in 71.4% of the subjects. Hypothyroidism risk factors were present in 53.6% of the patients, while in 46.4% there were none, which indicates the necessity of carrying out screening tests in all pregnant women as a method of choice, regardless of the presence of thyroid disease risk factors. A positive correlation between the frequency of thyroid diseases risk factors, TSH, and the age of the patients in the presented study serves as an additional argument for the necessity of universal screening.
Abalovich M, Amino N, Barbour LA, Cobin RH, De Groot LJ, Glinoer D, et al. Management of thyroid dysfunction during pregnancy and postpartum: an Endocrine Society Clinical Practice Guideline. Clin Endocrinol Metab 2007;92:1-47.
Vaidya B, Anthony S, Bilous M, Shields B, Drury J, Hutchison S, et al. Detection of thyroid dysfunction in early pregnancy: Universal screening or targeted high-risk case fi nding? J Clin Endocrinol Metab 2007;92:203-207.
Horacek J, Spitalnikova S, Dlabalova B, Malirova E, Vizda J, Svilias I, et al. Universal screening detects two-times more thyroid disorders in early pregnancy than targeted high-risk case fi nding. Eur J Endocrinol 2010;163:645-650.
Negro R, Schwartz A, Gismondi R, Tinelli A, Mangieri T, StagnaroGreen A. Universal screening versus case fi nding for detection and treatment of thyroid hormonal dysfunction during pregnancy. J Clin Endocrinol Metab 2010;95:1699-1707.
Abalovich M, Gutierrex S, Alcaraz G, Maccallini G, Garcia A, Levalle O. Overt and subclinical hypothyroidism complicating pregnancy. Th yroid 2002;12:63–68.
Casey BM, Dashe JS, Wells CE, McIntire DD, Byrd EW, Leveno KJ, et al. Subclinical hypothyroidism and pregnancy outcomes. Obstet Gynecol 2005;105:239-245.
Männistö T, Vääräsmäki M, Pouta A, Hartikainen AL, Ruokonen A, Surcel HM, et al. Th yroid dysfunction and autoantibodies during pregnancy as predictive factors of pregnancy complications and maternal morbidity in later life. J Clin Endocrinol Metab 2010;95:1084-1089.
Szybiński Z. Iodine prophylaxis in Poland in light of the WHO recommendation on reduction of the daily salt intake. Pediatr Endocrinol Diabetes Metab 2009;15:103-107.
de Escobar GM, Obregón MJ, del Rey FE. Iodine defi ciency and brain development in the fi rst half of pregnanc. Publ Health Nutr 2007;10:1554-1570.
Gyamfi C, Wapner ME, D’Alton ME. Th yroid dysfunction in pregnancy: the basic science and clinical evidence surrounding the controversy in management. Obstet Gynecol 2009;113:702-707.
Obregon MJ, Calvo RM, Del Rey FE, de Escobar GM. Ontogenesis of thyroid function and interactions with maternal function. Endocr Rev 2007;10:86-98.
Szybiński Z, Zdebski Z, Lewiński A, et al. Infl uence of iodine supplementation on the incidence of goiter and ioduria in pregnant women with iodine defi ciency, a multi-centre study. Endokrynol Pol 1998;49(3):151-162.
Brabant G, Beck-Peccoz P, Jarzab B, Laurberg P, Orgiazzi J, Szabolcs I, et al. Is there a need to redefi ne the upper normal limit of TSH? Eur J Endocrinol 2006;154:633-637.
Negro R, Schwartz A, Gismondi R, Tinelli A, Mangieri T, StagnaroGreen A. Increased pregnancy loss rate in thyroid antibody negative women with TSH levels between 2.5 and 5.0 in the fi rst trimester of pregnancy. J Clin Endocrinol Metab 2010;95:E44-48.
Stricker R, Echenard M, Eberhart R, Chevailler MC, Perez V, Quinn FA, et al. Evaluation of maternal thyroid function during pregnancy: the importance of using gestational age-specifi c reference intervals. Eur J Endocrinol 2007;157:509-514.
Gilbert RM, Hadlow NC, Walsh JP, Fletcher SJ, Brown SJ, Stuckey BG et al. Assessment of thyroid function during pregnancy: fi rst-trimester (weeks 9-13) reference intervals derived from Western Australian women. Med J Aust 2008;189:250-253.
Negro R, Formoso G, Mangieri T, Pezzarossa A, Dazzi D, Hassan H. Levothyroxine treatment in euthyroid pregnant women with autoimmune thyroid disease: eff ect on obstetrical complications. J Clin Endocrinol Metab 2006;91:2587-2591.
Poppe K, Velkeniers B, Glinoer D. Th e role of thyroid autoimmunity in fertility and pregnancy. Nat Clin Pract Endocrinol Metab 2008;4:394- 405.
Brent GA. Diagnosing thyroid dysfunction in pregnant women: Is case fi nding enough? J Clin Endocrinol Metab 2007;92:39-41.
Baloch Z, Carayon P, Conte-Devolx B, Demers LM, Feldt-Rasmussen U, Henry JF, et al. Laboratory medicine practice guidelines. Laboratory support for the diagnosis and monitoring of thyroid disease. Guidelines Committee, National Academy of Clinical Biochemistry. Th yroid 2003;13:3-126.
Baskin HJ, Cobin RH, Duick DS, Gharib H, Guttler RB, Kaplan MM, et al. American Association of Clinical Endocrinologists medical guidelines for clinical practice for the evaluation and treatment of hyperthyroidism and hypothyroidism. Endocr Pract 2002;8:457-469.