TY - JOUR
T1 - Challenges in the evaluation of urinary iodine status in pregnancy
T2 - The importance of iodine supplement intake and time of sampling
AU - Andersen, Stine Linding
AU - Sørensen, Louise Kolding
AU - Motavaf, Anne Krejbjerg
AU - Møller, Margrethe
AU - Laurberg, Peter
PY - 2014
Y1 - 2014
N2 - Objectives: Median urinary iodine concentration (UIC) is the recommended method to evaluate iodine status in pregnancy, but several factors may challenge the interpretation of the results. We evaluated UIC in pregnant women according to (1) sampling in the hospital versus at home, (2) time of the most recent iodine supplement intake prior to sampling, and (3) members of their household.Study Design: Danish crosssectional study in the year 2012. Pregnant women (n = 158), their male partners (n = 157) and children (n = 51) provided a questionnaire with detailed information on iodine supplement intake and a spot urine sample obtained in the hospital and/or at home for measurement of UIC and urinary creatinine concentration.Results: In the pregnant women providing a urine sample both in the hospital and at home (n = 66), individual UIC (p = 0.002) and urinary creatinine concentration (p = 0.042), but not estimated 24-hour urinary iodine excretion (p = 0.79), were higher when sampling was at home. Median UIC was dependent on the time of the most recent iodine supplement intake prior to sampling [same day (n = 79): 150 μg/l (95% CI 131-181 μg/l), the day before (n = 51): 105 μg/l (78-131 μg/l), several days ago/non-user (n = 28): 70 μg/l (56-94 μg/l), p < 0.001]. The pattern was similar in the male partners. Apart from a more frequent iodine supplement intake in pregnancy (87.3% vs. partners 15.9%), no systematic differences were observed in urinary measurements between the pregnant women and their partners.Conclusions: Time of spot urine sampling and time span from iodine supplement intake to spot urine sampling should be considered when evaluating urinary iodine status in pregnancy.
AB - Objectives: Median urinary iodine concentration (UIC) is the recommended method to evaluate iodine status in pregnancy, but several factors may challenge the interpretation of the results. We evaluated UIC in pregnant women according to (1) sampling in the hospital versus at home, (2) time of the most recent iodine supplement intake prior to sampling, and (3) members of their household.Study Design: Danish crosssectional study in the year 2012. Pregnant women (n = 158), their male partners (n = 157) and children (n = 51) provided a questionnaire with detailed information on iodine supplement intake and a spot urine sample obtained in the hospital and/or at home for measurement of UIC and urinary creatinine concentration.Results: In the pregnant women providing a urine sample both in the hospital and at home (n = 66), individual UIC (p = 0.002) and urinary creatinine concentration (p = 0.042), but not estimated 24-hour urinary iodine excretion (p = 0.79), were higher when sampling was at home. Median UIC was dependent on the time of the most recent iodine supplement intake prior to sampling [same day (n = 79): 150 μg/l (95% CI 131-181 μg/l), the day before (n = 51): 105 μg/l (78-131 μg/l), several days ago/non-user (n = 28): 70 μg/l (56-94 μg/l), p < 0.001]. The pattern was similar in the male partners. Apart from a more frequent iodine supplement intake in pregnancy (87.3% vs. partners 15.9%), no systematic differences were observed in urinary measurements between the pregnant women and their partners.Conclusions: Time of spot urine sampling and time span from iodine supplement intake to spot urine sampling should be considered when evaluating urinary iodine status in pregnancy.
KW - 24-hour urinary iodine excretion
KW - Household
KW - Iodine supplement
KW - Pregnancy
KW - Urinary creatinine concentration
KW - Urinary iodine concentration
U2 - 10.1159/000365145
DO - 10.1159/000365145
M3 - Journal article
SN - 2235-0640
VL - 3
SP - 179
EP - 188
JO - European Thyroid Journal
JF - European Thyroid Journal
IS - 3
ER -