Lack of knowledge about iodine has been suggested as a risk factor for iodine deficiency in pregnant women but no studies have addressed this issue in Portugal. So, the aim of this study was to investigate iodine knowledge among Portuguese pregnant women and its association with iodine status.
IoMum, a prospective observational study, included 485 pregnant women recruited at Centro Hospitalar e Universitário de S. João, Porto, between the 10th and 13th gestational weeks. Partial scores for knowledge on iodine importance, on iodine food sources or on iodised salt were obtained through the application of a structured questionnaire. Then, a total iodine knowledge score was calculated and grouped in low, medium and high knowledge categories. Urinary iodine concentration (UIC) was measured in spot urine samples by inductively coupled plasma mass spectrometry.
54% of pregnant women correctly recognized iodine as important to neurocognitive development, 32% were unable to identify any iodine rich food and 71% presented lack of knowledge regarding iodised salt. 61% of women had a medium total score of iodine knowledge. Knowledge on iodine importance during pregnancy was positively associated with iodine supplementation and also with UIC. Nevertheless, median UIC in women that correctly recognized the importance of iodine was below the cut-off for adequacy in pregnancy (150 µg/L).
In conclusion, knowledge on iodine importance associated positively with iodine status. Despite this, recognizing iodine importance during pregnancy may not be sufficient to ensure iodine adequacy. Literacy promoting actions are urgently needed to improve iodine status in pregnancy.