Abstract
Objective: To observe the effect of Combined oral contraceptive pills (COCPs) on activated protein C (APC) resistance after three months of its use and mean change from baseline and was stratified according to age groups and parity.
Methodology: This cross-sectional prospective descriptive study was conducted in Department of Pathology, Post Graduate Medical Institute, Lahore from 1/03/2018 to 02/03/2019. It included 54 female patients aged between 18-45 years who were scheduled by the family planning clinic of Lahore General Hospital, Lahore to start second generation oral contraceptive pills (OCP). Blood samples were collected and activated protein C resistance was assessed before the start of OCP and then after 3 months of onset of contraceptive use.
Results: Mean age of women was 29.5±5.3 years. The parity ranged from 1 to 6 (mean 3.06±1.20). APC resistance increased significantly as seen from a decrease in PCAT/PCAT-0 ratio with a mean change of 0.39±0.23 (p<0.001). Similar change was observed across various subgroups based on patient’s age and parity.
Conclusion: Continuous use of second-generation OCP for 3 months induces a prothrombotic state in the women by developing APC resistance in the absence of any prothrombotic condition. The monitoring of coagulation profile in a patient on oral contraceptives can aid in timely identification and management of hypercoagulable state, which may improve the outcome of such cases in future.

Key words: Oral Contraceptives, hormonal contraceptives, APC Resistance, Activated Protein C Resistance, Protein C, hypercoagulable state, hypercoagulability, thrombosis, deep vein thrombosis.