This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Non-Hormonal - Barrier Methods, Subject name: Gynaecology & Obstetrics
Highest failure rate is seen in: 
Select and explain. 
A. OCP, B. Condom, C. Cu-T, D. Depot injection
B: Condom
Answer: B: Condom 
Explanation: Ans: b (Condom) Ref: Shaw, 13th ed, p. 217Measurement of contraceptive efficacyPearl index: -Pregnancy rate per 100 women yearsPearl index =Total accidental pregnancy x 1200Total months of exposure to unintended pregnancyLife table techniquePregnancy rate is expressed as 100 women per year.Failure rates CondomNatural FP methodSpermicidesWithdrawalOther vaginal barriers1221211821 IUCD - Medicated1Inert3Progesterone only pill3Combined OCP1 -8 (0.1 if correctly used)Injectable contraceptive0.1 -0.4Female sterilization0.4Vasectomy0.2Implant0.4