“Dynamic Monitoring of Hypothyroidism During Pregnancy” article [Response to Letter]

Dear editor

We would like to appreciate the thoughtful and generous comments provided to us in the letter to the editor, and we also thank the editors for the chance to respond to the comments offered and expand discussion of our work.

The reader puts emphasis on the importance of specific ranges of thyroid stimulating hormones for the diagnosis of hypothyroidism in pregnancy at different stages of pregnancy. It is crucial to note that the range of values for thyroid stimulating hormones is different according to the trimester of pregnancy. Accordingly, the American Thyroid Association guideline 2011 was used in our study to evaluate the results of thyroid stimulating hormone taking a reference range of 0.3–3.0 m Iu/L for the third trimester of pregnancy.¹ We have used the reference value for the third trimester of pregnancy because our study participants were mainly in the third trimester. However, the detection of thyroid disorders during pregnancy must be initiated prior to conception or in the early stages of pregnancy because the adverse outcome of hypothyroidism can occur throughout the pregnancy.² Therefore, the study evaluated the prevalence of hypothyroidism in pregnancy that could have existed throughout pregnancy. Moreover, we included pregnant mothers who were presented during delivery in the study period as our objective was to analyse pregnancy outcomes during delivery. However, we would like to remind our readers that treatment has to be started as soon as the diagnosis is made. As a result, complications could be prevented early.

In addition, the reader has also pointed out another important issue. Various studies have recommended the use of specific reference ranges of thyroid stimulating hormones for particular regions.³ However, there are inadequate studies in the region to establish specific references of thyroid stimulating hormone values in our study area. Therefore, we have used the standard 0.3–3.0 m IU/L reference value for the third trimester of pregnancy. Moreover, our study would contribute to establishing local thyroid stimulating hormone reference ranges for the specific area.

Finally, one of the novelties of our study is that we have analyzed the adverse outcomes of pregnancy associated with hypothyroidism in addition to the magnitude of the disorder. Therefore, we highlight the importance of early screening for thyroid disorders in pregnancy and adequate treatment throughout the pregnancy to prevent adverse pregnancy outcomes.⁴