218SERUM BETA HCG AS AN ADJUNCT TO SONOGRAPHY FOR PREDICTION OF MEDICAL ABORTION OUTCOMEBackground: Medical abortion is gaining widespread popularity in India. Follow up visit to ensure complete abortion forms an important component of medical abortion. Follow up by measuring serial beta HCG can save time, prevents loss of wages associated with hospital visits without compromising the quality of services. Therefore, the present study was planned to assess the diagnostic ability of serum Beta HCG in detecting complete abortion following medical methods of abortion (MMA) and compare it with traditional method of transvaginal ultrasound (TVS) in predicting the medical abortion outcomes. Methods: It was a prospective observational study. Women with single intrauterine pregnancy upto 7 weeks gestation willing for medical abortion were included. Women were administered mifepristone and misoprostol as per regimen. On day 1, 5 and 14 serum beta HCG and TVS were done. The primary outcomes were percentage change in serum beta hCG and sonographic parameters. Receiver operating characteristic (ROC) was used to find out the cut off point of Endometrial thickness(ET) and percentage decline in serum beta HCG in predicting medical abortion outcome. Results: Study included 60 women. On day 14, percentage decline in serum beta HCG had better sensitivity as compared to ET (98.24% versus 87.71%) in diagnosing completeness of abortion. The maximum diagnostic accuracy occurred when cut off percentage decline in serum beta HCG on day 14 was 76% and ET was 12mm. Conclusion: Day 14 percentage decline in serum beta HCG has best sensitivity and diagnostic accuracy as compared to sonographydrku93@gmail.comResearch1022020Abortion,Ultrasound,beta HcGKavita Agarwal,Rupali Dewan,Pooja UniyalDepartment Obstetrics & Gynaecology, VMMC & Safdarjung Hospital, Delhi, India.,Department Obstetrics & Gynaecology, VMMC & Safdarjung Hospital, Delhi, India.,Department Obstetrics & Gynaecology, VMMC & Safdarjung Hospital, Delhi, India.