Purpose: To study the association and correlation between the amniotic fluid index, random glucose concentration, and serum glucose concentration after avoiding oral intake of sugar in a pregnant female with polyhydramnios.Methods: The research was performed on pregnant women with polyhydramnios (n=104 ) after 28 weeks. USG was performed using a SAMSUNG HS 70A (Samsung Electronics Pvt. Ltd., Seoul, South Korea) and a GE Voluson P8 (GE Healthcare, Little Chalfont, UK). We measured amniotic fluid index and took a blood sample for hemoglobin (Hb)A1C, fasting blood glucose, post-prandial and random blood glucose, and also performed a glucose tolerance test in pregnant women.Results: This is a prospective study, all 104 patients that were recruited in this study were pregnant females with polyhydramnios mainly from the urban and rural zone with different age groups (between 21 and 37 years). In our study, we observed that after avoiding oral intake of sugar in pregnant females with polyhydramnios, it was concluded that the amnionic fluid index lies towards the lower side. Polyhydramnios is more common in the urban zone and among older pregnant females. Out of 104 pregnant females with polyhydramnios, 82 were diagnosed with gestational diabetes after 28 weeks.Conclusion: In this study, we have concluded that the earliest and most sensitive predictor for gestational diabetes is a rise in the amniotic fluid index which could have been prevented by avoiding oral intake of sugar. Early prediction of gestational diabetes can be made by amniotic fluid index even before glucose concentration. We observed that by reducing oral intake of sugar, the amniotic fluid index drops down in pregnant females