Investigation of the relationship between early pregnancy losses and urinary iodine concentration

Abstract

Aim: The aim of this study was to evaluate the relationship between the development of spontaneous abortion (SpA) and hypothyroidism developing during pregnancy in patients who were euthyroid before pregnancy. Material and Methods: This prospective study included 44 women with singleton pregnancies with a history of pregnancy loss and 43 women with singleton pregnancies with no history of loss. All patients were in the first 12 weeks of pregnancy. Age, gestational age, number of miscarriages, gravida, body mass index, free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulant hormone (TSH), and urinary iodine concentration levels (UIC) were measured. Parameters were compared between the groups using the independent samples t-test. Correlation analysis was performed to determine relationships between the parameters in the groups. The Pearson correlation coefficient was calculated. A value of p<0.05 was considered statistically significant. Results: The mean UIC (145.3 +/- 56.01 mu g/L) in the SpA group was lower than in the non-abortus group (186.9 +/- 68.80 mu g/L) (p= 0.001). In the SpA group, there more hypothyroidic patients, and FT4 values were statistically significantly low (p=0.004). Correlation analysis determined a significant correlation between UIC and SpA (r: -0.438((SIC)), p<0.001). As a result of the binary logistic regression analysis, recurrent SpA and moderate and severe iodine deficiency were seen to have contributed to the development of SpA in the current pregnancy. Discussion: The results of this study showed that even in patients who were euthyroid before pregnancy, with the increasing iodine requirement in pregnancy, iodine deficiency can emerge and this can cause hypothyroidism and increase the risk of the development of SpA.