Mild iodine deficiency in women after spontaneous abortions living in an iodine‐sufficient area of Czech Republic: prevalence and impact on reproductive health

Abstract

Iodine deficiency is associated with thyroid dysfunction and adverse pregnancy outcomes. The aim of our study was to investigate the status of iodine saturation in women after spontaneous abortion (SpA) residing in an iodine-sufficient area and to evaluate their subsequent reproductive health. Nonrandomized prospective follow-up study. We compared urinary iodine concentration (UIC) in 171 women 2-8 weeks (median 4) after an early SpA with age-matched controls. Women with known thyroid diseases were excluded. We also analysed a relationship of UIC to serum thyroid-stimulating hormone, free thyroxine, antibodies against thyroid peroxidase and thyroid ultrasound. Afterwards, we followed the women for a median of 38 months (range 12-47). We used a multivariate regression analysis to assess the influence of iodine status and other thyroid biochemical and ultrasound parameters on their subsequent reproductive health. Women after SpA were almost twice as likely to suffer from mild iodine deficiency and had lower median UIC as compared to age-matched controls [rate 105/181 (58·0%) vs 57/181 (31·5%), P < 0·001, medians UIC 92·00 vs 117·80 mcg/l, P < 0·001]. UIC was not influenced by the use of iodine supplements in the previous pregnancy. We did not find any association neither between UIC and thyroid dysfunction and/or thyroid antibodies, nor between UIC and rates of subsequent successful pregnancies or obstetric complications. More than half of women after SpA residing in an iodine-sufficient area are suffering from mild iodine deficiency. However, it does not seem to have a negative impact on their subsequent reproductive health.