Importance of Universal screening for thyroid disorders in first trimester of pregnancy

Indian J Endocrinol Metab. 2014 Sep;18(5):735-8. doi: 10.4103/2230-8210.139221.

Abstract

Objective: To determine the importance of screening for Thyriod disorders in the first trimester of pregnancy.

Materials and methods: The Study was conducted on 305 patients which were were randomly selected and screened on OPD basis by TSH levels (cut off level 0.10-2.50 mIU/ml).

Results: In the 305 women screened mean age was 24.46 years, mean gestational age was 9.09 weeks, 89.83% were euthyroid, 9.8%were hypothyroid, 0.32% were hyperthyroid. Incidence of hypothyroidism in high risk population was 20.58% and in normal population was 6.7%. There was significant association of thyroid disorders with high risk factors (P < 0.001). In hypothyroid women 46% had adverse perinatal outcomes and 53.33% had normal outcomes. This shows statistically significant association abnormal TSH values with adverse pregnancy outcomes (P < 0.001). In abnormal perinatal outcomes 6.2% women had Caesarean section out of them 73.68% were euthyroid, 26.31% were hypothyroid 1.9% had preterm labour, out of them 50% were euthyroid, 50% were hypothyroid. Out of 2.2% spontaneous abortions 28.5% were in euthyroid group while 71.4% were in hypothyroid group. There was 1 term stillbirth in hypothyroid group. This study showed significant association between abnormal thyroid stimulating hormone (TSH) values and adverse perinatal outcomes (P < 0.001).

Conclusion: There is significant correlation between risk factors and hypothyroidism. So high risk screening is mandatory in early pregnancy. But if we screen only high risk population we would miss 4.6% cases which could have been diagnosed and treated earlier. Therefore it is important to screen all pregnant women in the first trimester, it should be made mandatory.

Keywords: Hypothyroidism in pregnancy; Universal screening; screening in first trimester.