However, the impact of iodine availability on thyroid function during pregnancy and on thyroid function reference ranges are understudied

However, the impact of iodine availability on thyroid function during pregnancy and on thyroid function reference ranges are understudied. thyroid function reference ranges are understudied. The aim of this study was to investigate the association between iodine intake and thyroid function during pregnancy. In a population-based pregnancy cohort including 2910 pregnant women participating in The Norwegian Mother and Child Cohort Study, we explored cross sectional associations of maternal iodine intake measured (1) by a food frequency questionnaire and (2) as iodine concentration in a spot urine sample, with plasma thyroid hormones and antibodies. Biological samples were collected in mean gestational week 18.5 (standard deviation 1.3) and diet was assessed in gestational week 22. Median iodine intake from food was 121?g/day time (interquartile range 90, AZD3229 Tosylate 160), and 40% reported use of iodine-containing health supplements in pregnancy. Median urinary iodine concentration (UIC) was 59?g/L among those who did Rabbit Polyclonal to RABEP1 not use health supplements and 98?g/L in the women reporting current use at the time of sampling, indicating mild to moderate iodine deficiency in both organizations. Iodine intake as measured by the food frequency questionnaire was not associated with the end result actions, while UIC was inversely associated with Feet3 (The results indicate that slight to moderate iodine deficiency impact thyroid function AZD3229 Tosylate in pregnancy. However, the variations were small, suggesting that normal research ranges can be determined based on data also from mildly iodine deficient populations, but this needs to be further analyzed. Introducing an iodine-containing product might temporarily inhibit thyroid hormone production and/or launch. fertilization (IVF). Analytical methods Samples of urine and blood were collected in the 50 participating private hospitals, and samples were shipped by regular mail (unrefrigerated shipment) inside a vacutainer for long-term freezing at a central biorepository (37). Storage temp was ?80C (?20C for whole blood). UIC was identified in the National Institute AZD3229 Tosylate for Health and Welfare (THL) in Helsinki (Finland) by inductively coupled plasmaCmass spectrometry (ICP-MS) using an Agilent 7800 ICP-MS system (Agilent Systems Inc., Santa Clara, CA). In brief, 100?L of urine sample was extracted using ammonium hydroxide remedy. Tellurium was used as an internal standard. Within the ICP-MS, m/z?=?127 was scanned for iodine dedication. The limit of quantification of the method was 2?g/L and the linearity was fertilization, %2.2Smoking in pregnancy, %??Occasionally14?Daily3.8Chronic illness, %8.9Household income, %??Low26?Medium43?High29?Missing1.9Iodine from food (g/day time), median (IQR)121 (90, 160)UIC (g/L), median (IQR)68 (35, 116)Urinary creatinine (g/L), median (90% range)0.76 (0.17, 1.92)UIC (g/g creatinine), median (IQR)91 (61, 139)UICCr (g/L), median (IQR)74 (55, 105)UIC, %??150?g/L (sufficienta)14?0C150?g/L (insufficienta)86?0C100?g/L68?0C50?g/L37Plasma Feet4 [pmol/L], median [95% range]12.6 [10.3, 15.7]Plasma Feet3 [pmol/L], median [95% range]4.9 [4.0, 6.0]Plasma TSH [mU/L], median [95% range]1.2 [0.4, 2.9]Plasma TPOAb positive,b %8.1Plasma TgAb positive,b %7.9Plasma ferritin (ng/mL), median (IQR)33 (20, 56)?Empty iron stores (P-Fe 12?ng/mL), %9.0?Low iron stores (P-Fe 12C29.9?ng/mL), %35Wopening blood selenium (g/L), median (IQR)102 (89, 117)?Low selenium ( 80?g/L), %10 Open in a separate windowpane aPopulation median UIC 150g/L is the recommended cutoff for defining inadequate iodine intake in pregnancy by the World Health Corporation. bAntibody positivity was defined as ideals above the 92nd percentile ( 6.6 IU/mL for TPOAb and 7 IU/mL for TgAb). IQR, interquartile range; SD, standard deviation; TgAb; thyroglobulin antibodies; TPOAb, thyroid peroxidase antibodies; UIC, urinary iodine concentration; UICCr, UIC modified for creatinine. Iodine intake and UIC Median habitual iodine intake from food based on the FFQ was 121?g/day time. Four percent experienced a determined iodine intake from food reaching the WHO recommended intake of 250?g/day time for pregnant women, and 30% reaching the recommended intake of 150?g/day time for nonpregnant ladies. The low intake was reflected in a low median UIC in product nonusers (59?g/L, fertilization. bAdditionally excluding TgAb positive ( 4.11 IU/mL according to manufacturer cutoff), fertilization were excluded. Ideals are from quantile regression and modified for maternal age, prepregnancy BMI, gestational age at sampling, urinary creatinine (when UICCr is the exposure), and energy intake (when iodine from food is the exposure). Results from crude models are reported in Supplementary Table S2. a(median UIC 60?g/L in nonsupplemented ladies) (21,47). Also, Rebagliato reported improved risk of elevated TSH in pregnant women taking health supplements comprising 200?g iodine per day or more compared to 0C100?g/day time (22). Contrary to this, no difference was seen in a recent RCT of iodine supplementation in pregnancy by Gowachirapant inside a.