The Prevalence of Thyroid Diseases in Pregnancy and it's Relation to Iron Deficiency - A Hospital Based Study

The thyroid gland and it's function are both affected physiologically by pregnancy. During pregnancy, the thyroid gland expands by 10% in iodine-sufficient women and to a higher extent in iodine-deficient women. Anemia is a worldwide health problem affecting 33% of non-pregnant women and 38% of pregnant women. According to Western literature, the prevalence of hypothyroidism in pregnancy is roughly 2.5 percent. In India, there are few reports of prevalence of hypothyroidism during pregnancy, with prevalence rates ranging from 4.8 percent to 11 percent. Hypothyroidism was shown to be prevalent in 13.13 percent of pregnant women in Dhanwal et al study, with the majority of these hypothyroid pregnant women having subclinical hypothyroidism. There were only few studies in India regarding this, hence this study was carried out with objectives of 1) To assess the prevalence of thyroid diseases in pregnancy 2) To evaluate association between iron deficiency and thyroid disorders in early pregnancy. This was across sectional study conductedbetween Jan 2017 to June 2019 at JSS Hospital, a tertiary care hospital in Mysuru.500 consecutive pregnant women aged 18-45 years in first trimester of pregnancy were recruited.Under all aseptic precautions, venous blood of about 5ml was drawn and sent for analysis of Hb, TSH, T3, T4, Anti TPO antibody and Serum Ferritin which were measured by chemiluminiscence method for all pregnant women. TSH value>2.5 but less than or equal to 10 with normal T4 were considered to have subclinical hypothyroidism, TSH value>10 irrespective of T4 values and TSH value >2.5 with low T4 values were considered to have overt Hypothyroidism(American Thyroid Association and National Guidelines). Out of 500 women, 9 were excluded because of pre analytical error, hence there were 491 pregnant women in the study. Among 491 pregnant women,156(31.77%) were hypothyroid and 7(1.42%) had thyrotoxicosis. Among 156 Hypothyroid women, 9(5.76%) had overt hypothyroidism and 147(94.23%) had subclinical hypothyroidism. Predominant symptom in Hypothyroid women was fatigue(35.6%) followed by hair loss(31.7%), cold intolerance(16.9%),dry skin(6.72%), constipation(2.65%), weight gain(2.24%) and poor memory(2.04%).Goitre was present in 10(6.41%) women. Among 491 pregnant women, 211(42.9%) had iron deficiency and 280(57%) had normal ferritin.Among 156 hypothyroid women,60 (38.46%) had low ferritin and 96(61.53%) had normal ferritin. Chi square analysis did not show any si