failure rate (contraception / efficacy of method)

Last reviewed 01/2018

Technique:

Method Failure Rate defined as (pregnancies / 100 woman-years (%) )
Norplant; failure rate 0.2-1.1 0.2-1.1
Implanon (3) fewer than 0.1 in 100 over 3 years (3)
Mirena coil 0.09
combined pill 0.2-0.3
mini-pill 0.3-5
condom 2-15
diaphragm and spermicide 5
IUCD (see below) 0.3-4
coitus interruptus 30
rhythm method 30 - 40
Depo Provera < 0.5
none 60-70

 

Interpretation - 5% failure rate means that if 100 women used this form of contraception, 5 would be pregnant within one year.

Reference:

  1. Drug and Therapeutics Bulletin 1996; 34 (12): 93-5.
  2. BNF 7.3
  3. NICE (October 2005). Long-acting reversible contraception