Association of Thyroid Status with Pregnancy Induced Hypertension and Impact of Levothyroxine Treatment

ABSTRACT

Background:Pregnancy induced hypertension is an important cause of maternal and fetal morbidity and mortality affecting 5-10% of pregnancies.PIH is more frequently associated with elevated TSH. Hypothyroidism is one of the causes of hypertension in nonpregnant state. Hypertension is completely reversible in 50% cases of hypothyroidism by levothyroxine therapy. Treating hypothyroidism in pregnancy may help to reduce PIH prevalence. Objectives- This is an observational study to find out association of PIH with hypothyroidism and to know result of levothyroxine treatment on PIH prevalence and its severity. Methods: 75 singleton pregnancies with PIH admitted to labour ward, evaluated with their TSH status in groupA. In Group B, 75 singleton pregnancies with subclinical or overt hypothyroidism treated with levothyroxine to maintain euthyroid state throughout pregnancy and observed for development of PIH. Overt hypothyroidism considered when TSH value ≥10 and subclinical hypothyroidism when TSH value between 3 and 10.. Result: Overt and subclinical hypothyroidism was present in 12% (9 out of 75) and 57.3%(43 out of 75) cases of PIH respectively. In group B, all hypothyroid pregnancies treated with levothyroxine throughout pregnancy, prevalence of PIH was 6.66% (5 out of 75) . Significant association of PIH and hypothyroidism demonstrated by Fisher’s exact test (p<0.001). PIH prevalence significantly reduced in treatment group demonstrated by chi square test (p<0.001). Conclusion: Subclinical and overt hypothyroidism prevalence is significantly high among PIH patients. Treating subclinical and overt hypothyroidism in pregnancy, reduces prevalence of PIH and its severity.