Prevalence of thyroid disorders in pregnant women with mild iodine deficiency

Abstract

To assess the prevalence of thyroid disorders in a region with mild iodine deficiency, this study was undertaken in a randomized sample of pregnant women during different gestational periods. Evaluations were performed in 215 women: thyroid ultrasound scanning, thyroid stimulating hormone (TSH), free thyroxine (T4) and thyroid peroxidase (TPO) antibodies. At the time of participation in the study, some women (90/215) had been receiving 150-200 micrograms iodine. Hypothyroidism was found in four women (1.86%). Positive TPO antibodies were seen in 34 of 215 women (15.8%), and TPO antibody level over 150 mU/l was found in 9.8% (21/215). There was no significant difference between TSH levels in women with positive or negative TPO antibodies. There were no differences in TSH level between the women receiving and those not receiving iodine prophylaxis. The prevalence of goiter in 211 euthyroid women was found to be 24.2% (51/211). in the group with iodine prophylaxis, thyroid volume was found to be significantly lower (t = 2.5; p = 0.02) than in women who had not received it, or had started it during the second trimester. By comparison of history data on the prevalence of aborted pregnancy between the group with positive (26.5%; 9/34) and the group with negative TPO antibodies (14.3%; 26/181), no significant differences were found. We conclude that, in mild iodine deficiency, pregnancy is related to a high risk of goiter, which can be prevented by iodine prophylaxis. TPO antibody carrier status in pregnant women is probably not associated with a significant risk of thyroid dysfunction or spontaneous abortion.

Systematic review and meta-analysis of the effects of iodine supplementation on thyroid function and child neurodevelopment in mildly-to-moderately iodine-deficient pregnant women

“…Studies were mostly based in Europe including Spain (14,16,17,32,33,(35)(36)(37)(38), Italy (39)(40)(41)(42)(43)(44), Norway (15,(45)(46)(47)(48), Denmark (49)(50)(51), France (31,52), Germany (53,54), Poland (55,56), Sweden (57), Latvia (58) and Hungary (59). Four studies were conducted outside Europe [Russia (60), Chile (61), Australia (62,63), India and Thailand (34)]. The sample-size ranged from 60 to 77, 164 in the observational studies and from 35 to 832 in the intervention studies.…”

“…The forms of iodine supplementation were iodised salt (three studies) (39,41,42), drops of potassium-iodide (KI) solution (two studies) (50,61), KI tablets (nine studies) (32)(33)(34)38,43,44,53,54,62), and iodine-containing multivitamin tablets (16 studies) (15,16,31,40,(45)(46)(47)(48)(49)51,52,(55)(56)(57)(58)(59). The exact iodine vehicle was unclear in five studiesit was either a KI or an iodine-containing multivitamin tablet (14,17,35,36,60); in two studies the iodine vehicle was not specified (37,63). In intervention studies, the dose of iodine ranged from 50 (43) to 300 µg/day (32,33,61), mainly as KI tablets.…”

THERAPY OF ENDOCRINE DISEASE: Impact of iodine supplementation in mild-to-moderate iodine deficiency: systematic review and meta-analysis

“…Iodine was administered in the form of potassium iodide (KI) preparations, iodine-containing vitamin preparations or iodised salt and one trial included an intervention arm which received KI in combination with levothyroxine (L-T 4 ) (29). Five observational studies also assessed the impact of iodine supplementation on maternal thyroid function (33,34,35,37,38). Of these, three were of moderate quality while two were low quality.…”

“…Nine RCTs (24,25,26,27,28,29,30,31,32) and eight observational studies (33,34,35,36,37,38,39,40) were included in the review. Seven RCTs were reported on the effects of maternal supplementation on maternal thyroid function (26,27,28,29,30,31,32,33,34,35,36,37,38,39,40). Of these, four RCTs also contained data on neonatal thyroid function (27,29,30,32).…”

Retrospective analysis of the preeclampsia cases delivered in our clinic between 2013 and 2017

“…Bostanc› and Taflkesen reported in their study conducted on pregnant women that the rate of hypothyroidism was 2.8%. [4] This rate was 15.8% in the study of Güzel et al, [5] 2.8% in the study of fienbayram, [3] and 1.8% in the study of Fadayev et al [33] According to 2017 report of Turkish Endocrinology and Metabolism Society, hypothyroidism prevalence during pregnancy was 0.3-0.5% for overt hypothyroidism and 2-3% for sub-clinical hypothyroidism. [2] Hypothyroidism rate of pregnant women in our study was higher than other studies.…”