Objectives: This study aimed to know the expression of GATA-3 in trophoblastic tissues and to explore its utility in confirmation of uncertain histopathological diagnosis. Materials and methods: It was a cross sectional study conducted in 2021 in a south Indian district in a tertiary care hospital from public sector. Around 64 specimens were taken up or the study. Specimen collection involved receiving samples in 10% formalin, followed by fixation in fresh formalin for 24 hours. Gross descriptions, reports of Hematoxylin and eosin staining were documented, followed by immunohistochemistry. GATA 3 IHC was performed on paraffin-embedded tissue specimens. For a positive result, nuclear expression within trophoblastic cells was required. This process ensured accurate assessment of GATA3 expression in trophoblastic tissues. Results: Mean (SD) age was 25.86 (5.52) years. GATA3 expression was negative for all 3 trophoblasts only for 1 case (1.6%). In a study of 64 specimens, all 56 consistent with products of conception showed 100% GATA3 expression in intermediate trophoblast and cytotrophoblast tissues, but only 20.4% displayed GATA3 expression in syncytiotrophoblast tissue. In 5 specimens identified as Hydatidiform mole, all showed 100% GATA3 expression in intermediate trophoblast and cytotrophoblast, with none showing GATA3 expression in syncytiotrophoblast tissue. If GATA3 expression is more pronounced in one trophoblast subtype, it is likely to also be more pronounced in the other trophoblast subtype, and the reverse holds true as well.Expression of GATA-3 expression was noted in trophoblastic tissues in > 98% specimen. Conclusion: The study cannot approve completely of its utility in confirmation of uncertain histopathological diagnosis.

GATA-3 expression, Immunohistochemistry, Trophoblast, Pregnancy, Unsafe abortion.