Thyroid Hormonal Status in Pregnancy and Pre- Eclampsia and Its Correlation with Maternal Age and Parity

Pre-eclampsia is defined as a triad of hypertension, edema and proteinuria. It usually occurs after 20 weeks of gestation producing cardiovascular, hematological, endocrinological and biochemical changes. It is a well recognized cause of maternal & fetal morbidity & mortality. A state of hypothyroxinemia exists in normal pregnancy, which is more pronounced in pre-eclampsia. The mechanism of hypothyroidism in pre-eclamptic women has not yet been clearly identified, but the changes in thyroid function during pregnancy are accounted for by high circulating estrogen levels. Aims and Objectives of the study was 1) to evaluate the thyroid hormonal status in normotensive pregnant females and in patients with pre-eclampsia. 2) to evaluate the influence of maternal age and parity on thyroid functions. 3) to find the correlation of thyroid hormones with albumin. A case control study was conducted on 40 diagnosed patients of preeclampsia and 40 age and parity matched normotensive pregnant subjects in the age group 20-40 years with singleton pregnancy, venous blood samples from both the groups were collected and assayed for thyroxine (T4), Tri-iodothyronine (T3), Thyroid Stimulating Hormone (TSH) and serum albumin. Serum TSH was increased significantly while T4 and T3 were decreased in pre-eclampsia as compared to normal pregnancy. No influence of parity and maternal age was observed on thyroid functions. A significant positive correlation was observed between serum albumin and T3 & T4 levels in preeclampsia, while there was a negative correlation between serum albumin levels and TSH. In the present study the result shows that T4 and T3 are significantly lower and TSH is significantly increased in pre-eclamptic patients compared to normotensive pregnant females. There is no effect of maternal age on thyroid functions in the patients, neither there is any difference in the two parity groups. Thyroid disorder may thus be one of the predisposing causes for pre-eclampsia. Hence, thyroid hormonal assay may be considered as a screening test for early diagnosis and treatment of pre-eclampsia and prevention of its complications.