Risk factors for malignant change in molar pregnancy

• Maternal age - 9 fold increase in risk in >40 years compared to 20-24 age group
• Initial method of evacuation - lowest risk after vacuum aspiration

• ABO blood group - highest risk in woman with blood group A and partner with blood group O; 
lowest risk in woman with blood group A and partner with blood group A

• Complete or partial mole - malignant potential higher with complete mole 7-16% require chemotherapy compared to 0.5% after partial mole

• Post-evacuation contraception - use of COCP before HCG levels have returned to normal is associated with increased need for chemotherapy