880CLINICAL SIGNIFICANCE OF CA-125 AND HCG LEVELS IN PREGNANCY AND ABORTION PATIENTS IN SOUTHINDIACA-125 is a glycoprotein and its origin is uncertain during pregnancy. It arises during the first trimester and return to a non-pregnancy range in late pregnancy. The aim of the study is to evaluate the relation between serum HCG, progesterone and CA125 as biochemical markers at different gestational ages in the first trimester for predicting pregnancy loss.According to these findings, it can be stated that the test is rather sensitive to differentiate the normal pregnancy and threatened abortion.In conclusion, the value of CA125 in recurrent abortions is still unclear and cannot be recommended on routine basis. On the other hand ?-HCG is highly sensitive as a single serum measurement for the prediction of pregnancy outcome revathisingh89@gmail.comResearch1122020CA-125, Pregnancy, Abortion, Threatened abortionRevathi R 1,Abi CAssistant Professor, Department of obstetrics and Gynecology, Tagore Medical College and Hospital, Rathinamangalam, Melakottaiyur, Chennai, Tamilnadu, India,Assistant Professor, Department of obstetrics and Gynecology, Sri Lakshmi Narayana Institute of Medical Sciences, (Affiliated to Bh-arath University, Chennai), Pondicherry, India.