Vol. 5, Issue 2, Part A (2023)

Pregnancy causes physiological changes in maternal thyroid function tests and changes are occasionally confused with thyroid abnormalities, therefore the aim of this study was to determine the TSH levels in the first trimester of pregnancy in women without a history of thyroid disease. And to determine the importance of screening of thyroid diseases in early pregnancy.
Methods: This descriptive analytic study consisted of 1200 pregnant mothers in their first trimester referring to Jondishapur university hospitals for prenatal care in the span of one year. Cases with incomplete data as well as pregnant mothers with a history of thyroid disorders were excluded. In addition to routine prenatal lab test TSH level was measured by enzyme-linked immunosorbent assay (ELISA) method. It should be noted that the documented information is confidential and will not be used in any other study. All TSH measured data was analyzed by SPSS software version 26 and All P values <0.05 were considered significant.
Results: Seventy percent of our cases were aged between 25 and 35 years old. The mean age of pregnant women was 29.44±0.13 and the mean of TSH level in the first trimester of pregnancy was 2.40±0.49.There was no significant relations between different age groups, abortion, number of pregnancies and diabetes in our cases and TSH level (p>0.05). However, there was a significant correlation between BMI, family history of thyroid diseases and hypertension in pregnant women without past medical history of thyroid diseases and TSH level in the first trimester of pregnancy (p<0.05).
Conclusions: The results of this study showed that TSH level in majority of our cases ranging from 2.5 to 3.9 mUl/ml, 310(25%) cases more than 2.5 mUl/ml and 188(15.66%) cases more than 3.9 mUl/ml. According to this study approximately 16% of our cases need assessment for hypothyroidism and required treatment. If screening of TSH in first trimester was not done 188 cases of hypothyroidism would not have been diagnosed, thus it is reasonable to implement this test in the routine prenatal care.