Screening for Thyroid Disorder in First Trimester of Pregnancy: A Cross-Sectional Study

Abstract

Background: Alteration in thyroid function is very common among females, in particular during pregnancy. The majority of them are clinically veiled, and with considerable differences in outcome of mother and fetus, even more serious maternal and fetal outcome if present during the first trimester. So, we conducted this study to explore the magnitude of thyroid problems during first trimester of pregnancy at a tertiary health care facility in Nepal and highlight the benefits of its early diagnosis. Methods: This was a cross-sectional study conducted over a period of 1 year among 160 pregnant females in their first trimester, attending to the outpatient department of a tertiary care center. Blood samples were collected from all the patients for thyroid function test which included measurement of serum levels of thyroid-stimulating hormone (TSH), free thyroxine (fT4), and free tri-iodothyronine (fT3). Pregnant females with previously diagnosed thyroid disorders or currently under medications were excluded. Results: Among the 160 patients included in the study, 25.83 years was the mean age. The mean body mass index (BMI) was 24.62 kg/m 2 and most of the patients were overweight (40.625%). Of the patients 53.12% were primigravida and 46.87% were multigravida. Based on the thyroid function tests, 91.25% were found to be euthyroid, 3.125% were hyperthyroid and 5.625% were hypothyroid. The prevalence of subclinical hyperthyroidism and overt hyperthyroidism was found to be 60% and 40% respectively and that of subclinical hypothyroidism and overt hypothyroidism was 55.6% and 44.4% respectively. None of the patients had symptoms of thyroid disorder (neither hyperthy-roidism nor hypothyroidism). The correlation between BMI and TSH among the pregnant females included in the study was statistically significant when tested by using Karl Pearson correlation coefficient (r = 0.164, P = 0.038). Conclusions: Based on this study, around one in every 12 pregnant women had thyroid disorder. Early identification of thyroid disorders and prompt initiation of treatment is very essential for the health of mother and fetus due to the significant maternal or fetal morbidity and mortality associated with thyroid disorders. Thus, routine screening for thyroid disorder should be considered during pregnancy.