Prevalence of Overt and Subclinical Thyroid Dysfunction Among Pregnant Women and Its Effect on Maternal and Fetal Outcome

Abstract

Aim To determine the current prevalence of thyroid dysfunction in normal pregnant women and to study the impact of thyroid dysfunction on maternal and fetal outcome. Methods 400 pregnant women between 13 and 26 weeks of gestation were registered for the study. Apart from routine obstetrical investigations, TSH tests were done. Free T4 and anti-TPO antibody tests were done in patients with deranged TSH. Patients were followed up till delivery. Their obstetrical and perinatal outcomes were noted. Results The prevalence of hypothyroidism and hyperthyroidism was 12 and 1.25 %, respectively. Adverse maternal effects in overt hypothyroidism included preeclampsia (16.6 vs. 7.8 %) and placental abruption (16.6 vs. 0.8 %). Subclinical hypothyroidism was associated with preeclampsia (22.3 vs. 7.8 %) as compared to the euthyroid patients. Adverse fetal outcomes in overt hypothyroidism included spontaneous abortion (16.6 vs. 2.39 %), preterm birth (33.3 vs. 5.8 %), low birth weight (50 vs. 12.11 %), intrauterine growth retardation (25 vs. 4.9 %), and fetal death (16.6 vs. 1.7 %) as compared to the euthyroid women. Adverse fetal outcomes in subclinical hypothyroidism included spontaneous abortion (5.5 vs. 2.39 %), preterm delivery (11.2 vs. 5.8 %), low birth weight (25 vs. 12.11 %), and intrauterine growth retardation (8.4 vs. 4.9 %) as compared to the euthyroid women. Conclusions The prevalence of thyroid disorders was high in our study with associated adverse maternal and fetal outcomes. Routine screening of thyroid dysfunction is recommended to prevent adverse fetal and maternal outcome.

A descriptive study of the prevalence of hypothyroidism among antenatal women and foetal outcome in treated hypothyroid women

“…In a study by Goldman C et al, the prevalence was 2.2% and another study by Ajmani et al, the prevalence was 9%. 3,5,6 In a study by Casey BM et al, the prevalence was 23% which is very high and inconsistent with our study. 7 In the present study, the prevalence of overt hypothyroidism was 1.6% which is comparable to the study by Cleary Goldman et al, where the prevalence was less than 1%.…”

“…5,6 The prevalence of overt hypothyroidism was 2.9% and another study by Ajmani et al showed prevalence of 3%; whereas a study by Sahu MT showed a higher prevalence of 4.58%. 2,3 In this study, no significant association was observed between preterm labour hypothyroidism. The incidence of preterm labour in subclinical hypothyroidism was 5% and in overt hypothyroidism was 12.5%.…”

“…5 In the study by Ajmani et al the prevalence of hypothyroidism was 12% which is higher than our study. 3 In our study, the prevalence of subclinical hypothyroidism was 4%. This is comparable to the study by Goel et al, where the prevalence of subclinical hypothyroidism was 3.4%.…”

“…Study by Ajmani et al found that maternal age was high in the overt hypothyroid with a mean age of 27.16+/-5.237 years. 3 In our study, among 28 hypothyroid women, 18 (6.5%) were above 25 years as compared to 10 (4.5%) women aged less than 25 years. This shows increasing prevalence of hypothyroidism as maternal age advances.…”

“…4 A study by Ajmani et al observed that the incidence of preterm birth in overt hypothyroidism was higher (33%) than the present study and in subclinical hypothyroidism, the incidence was 11.2% compared to euthyroid women. 3 Casey B M et al found that preterm birth was almost 2 fold higher in women with subclinical hypothyroidism. 7 In the present study, 5% subclinical hypothyroid women had foetal death and 12.5% overt hypothyroidism women had foetal death which is much higher compared to 0.4% cases in euthyroid women.…”