I went to the Planned Parenthood web site,
Planned Parenthood Birth Control
to see the effectiveness of various birth control methods. The effectiveness is based on "normal" use by a couple for a year, from Planned Parenthood data. I calculated the 5 year pregnancy rates based on the 1 year rates. Here is a table of the effectiveness: Method % Pregnancies per year % per 5 years ---------------------- ---------------------- -------------- Condom (Male) 15% 56% Condom (Female) 21% 69% Diaphram/Cervical Cap 16% 58% IUD 1% 5% Pill 8% 34% Depo-provera (shots) 0.3% 1% Explanation, example the Male Condom: Out of 100 couples using the male condom for one year, 15 women will become pregnant. Out of 100 couples using the male condom for five years, there will be 56 pregnancies. (Some of the women may become pregnant more than once.) This means that 56 women out of 100 will become pregnant if they have sex with condoms for 5 years. Those odds are worse than flipping a coin! With the IUD there is a 1 in 20 chance of getting pregnant within 5 years, much better than condoms or the diaphram, which are worse than 50-50.