Subclinical hypothyroidism in pregnancy and outcomes

Abstract

Background: Screening for subclinical hypothyroidism is essential in all pregnant women, especially in the Indian context, as Indian women have increased risk of developing iodine deficiency during pregnancy. Hence this study was undertaken to study the prevalence of subclinical hypothyroidism. Emphasis was put to know the need for universal screening and also the obstetric outcome in terms of perinatal morbidity and mortality and maternal morbidity were assessed.Methods: It was a prospective analytical study. Sample size consisted of 200 pregnant women attending antenatal OPD. Thyroid profile (serum TSH, FT3 and FT4) was done during first visit and in subsequent trimester of each pregnant woman. The results were analyzed taking into consideration recent endocrine society guidelines. Patients with normal thyroid levels were taken as controls. Detailed history taken, physical examination and routine laboratory investigations were done. Patients with SCH were started on Levothyroxine and serial monitoring of TSH done until delivery. The patients were followed up to assess the mode of delivery, maternal and fetal outcome and any associated co-morbidities to serve the secondary objective of the study. Babies of SCH mothers were screened as well to rule out congenital hypothyroidism.Results: Incidence of SCH was found to be 9.5% in the patients studied. Pregnant women with SCH had increased risks of developing anemia (31.5%), preeclampsia (15%), GDM (5%) and prematurity (10%), higher cesarean section rate (36.8%). Neonates of women with SCH had higher incidence poor APGAR score (47.36%), LBW (15%), NICU admission (10%), IUGR (5%). Increased maternal age and more BMI were associated with higher incidence of subclinical hypothyroidism.Conclusions: Prevalence of subclinical hypothyroidism among pregnant women is fairly high among Indians. Screening for subclinical hypothyroidism has to be included as a routine screening test and should be treated accordingly to improve maternal and fetal outcomes.

Prevalence of sub clinical hypothyroidism and pregnancy outcome: a prospective comparative study

“…11 Risk of prematurity was more in SCH patient than euthyroid pregnant women but the relation was statistically insignificant. Same was seen in study done by Sannaborraiah A et al 10 In our study caesarean deliveries was significantly higher in SCH pregnant women compared to euthyroid pregnant women. This observation was statistically significant.…”

“…Similar association had been seen in study done by Sannaboraiah A et al, compared with euthyroid pregnant women, pregnant women with SCH had a higher risk of preeclampsia. 10 The relation was statistically significant. A similar association has been found in the study done by Wilson et al, there was a statistically significant association between thyroid disorders and the risk of PIH, mild to severe pre-eclampsia.…”

“…Sannaborraiah A et al had shown similar results i.e., cesarean section rate was statistically higher among pregnant women with subclinical hypothyroidism. 10 The incidence of LBW was less in SCH pregnant patient compared to euthyroid patients. The relation was statistically insignificant.…”

Prevalence and feto-maternal outcomes of subclinical hypothyroidism in pregnancy among mothers attending a tertiary care hospital of Darjeeling District, West Bengal, India

“…Similar to what has been reported by Sannaboraiah et al, the incidence of premature birth was also found to be significantly higher in the SCH group as compared to euthyroid group (P=0.035). 27 Consequentially, it was seen that the incidence of LBW babies was also significantly higher in the SCH group mothers (P=0.004), a finding that also conforms to that reported by Sannaboraiah et al, and Goel et al 27,28 Limitations of the study Two thyroid function tests were performed in our study to screen pregnant subjects. Measuring antithyroid antibodies would have provided more precise data.The study population was not followed up after delivery.…”

Levothyroxine replacement in subclinical hypothyroidism during pregnancy and its effect on fetomaternal outcome

“…There was a significant effect of maternal SCH in pregnancy on fetal distress in utero (p=0.003) [11] Männistö et al reported that maternal hypothyroidism has previously been shown to increase risk for neonatal intensive care treatment [10] . Sannaboraiah et al reported risk of NICU admission in 15% subthyroid females receiving levothyroxine whereas neonates of 27% cases with overt hypothyroidism required NICU admission [13] .…”