Thyroglobulin as an adjunct biomarker for assessing thyroid function during pregnancy

Thyroglobulin has been identified as a marker for thyroid cancer monitoring. However, researchers have proposed and employed it as a biomarker to assess iodine-dependent thyroid dysfunction during pregnancy. Pregnancy is a hyperdynamic state that significantly strains the mother's iodine stores due to the demands of the foetus. This study combined thyroglobulin and thyroid function tests to see their impact on identifying more patients who are at risk for thyroid disorders in pregnancy. The aim of the study was to determine thyroglobulin as an adjunct biomarker in thyroid function assessment in pregnancy.

Participants were across five centers, and the study was conducted over a period of 9 months (June 2019-February 2020). The study comprised a cohort of 250 pregnant women who were attending their antenatal clinic visits. These participants were selected randomly using a table of random numbers. Blood samples were taken and analyzed using immunoassay techniques. The data were analyzed using Statistical Package for Social Sciences (SPSS), version 21 (IBM, Chicago, IL).

Thyroid-stimulating hormone (TSH) assay only identified 35 (14%) participants, whereas the combination of the TSH and Tg assays identified 50 (20%) participants. Thyroglobulin and free thyroxine measurements revealed the presence of hyperthyroidism in 15 (9.6%) and hypothyroidism in 8 (3.2%). Using both TSH and thyroglobulin, we identified 54 (21.6%) participants as having thyroid dysfunction, with a higher prevalence of 40 (16%) hypothyroid participants compared to 14 (5.6%) hyperthyroid participants.

Thyroglobulin is valuable during pregnancy, with the ability to reflect iodine status as a sensitive marker in identifying early thyroid dysfunction.