SAT-136 Pregnancy and Neonatal Outcomes in Women with Mild TSH Elevation (2.5-4 mIU/L) :A Retrospective Study from South India

Abstract Disclosure: N. Kudugunti: None. L. Sudhakaran: None. D.P. Thuli: None. S. Edigakornapalli: None. R.K. Sahay: None. Background: Thyroid hormone plays a crucial role in pregnancy, and mild TSH elevation (2.5-4 mIU/L) is commonly encountered, but its impact on pregnancy and neonatal outcomes remains unclear. The treatment practices in managing pregnant women with mild TSH elevation (2.5 - 4 mIU/L) is highly variable, especially where anti-TPO testing is not routinely available. This study aimed to evaluate whether levothyroxine treatment in pregnant women with TSH levels between 2.5 and 4 mIU/L influences pregnancy and neonatal outcomes. Methodology: This retrospective study reviewed data from women with singleton pregnancies who delivered at a tertiary care center in South India between January 2022 and December 2023. A waiver of consent was obtained due to the use of de-identified data, with the goal of evaluating pregnancy and neonatal outcomes in women with mild TSH elevation (2.5-4 mIU/L). Inclusion criteria included delivered women in the postnatal ward, and exclusion criteria included those with multiple pregnancies, missing TSH values, or pre-existing thyroid disorders. A structured proforma was used to collect data on detailed history, clinical examination, and antenatal investigations across all trimesters. Delivery and neonatal outcomes, including gestational age, mode of delivery, neonatal complications, and birth weight, were also documented. The subjects were divided into treated and untreated group and was compared to women with TSH between 0.5 and 2.5 mIU/L. Statistical analysis was done to investigate the effect of treatment on pregnancy and neonatal outcomes. Results: Among 854 pregnant women with TSH levels between 2.5 and 4 mIU/L, 408 (47.7%) received levothyroxine treatment, while 446 remained untreated. These two groups were compared to 416 women with TSH levels between 0.5 and 2.5 mIU/L. Pregnant women with TSH between 2.5 and 4 mIU/L were older and overweight/obese compared to pregnant women with TSH below 2.5 mIU/L. The incidence of anaemia was significantly higher in the group with TSH between 2.5 and 4 mIU/L. Rates of gestational diabetes and preeclampsia were not significantly different across the groups. The cesarean section rate was also comparable among the groups. Preterm birth rates (<37 weeks) did not differ significantly between the treated and untreated groups. Neonatal outcomes, including NICU admissions, were also not different across the groups. Conclusion: Treatment of pregnant women with mildly raised TSH levels did not show any significant difference in pregnancy and neonatal outcomes in this study. Presentation: Saturday, July 12, 2025