how much are condoms actually effective

We know that condoms are the
best choice (except from abstinence) for preventing pregnancy and
sexual transmitted diseases.
But how much are they really effective?

Well, the statistics say that twelve of a hundred women whose partners
use condoms get pregnant per year (88% efficiency). The probability of
getting pregnant per one sexual intercourse is 1 : 2500.

If you follow all the instructions and use the condom perfectly its
effectiveness is even higher, rising up to 97%. This means that if 100
couples use the male condom all the time and always use it perfectly,
3 women will become pregnant in one year.

And how effective is the condom against Sexual Transmitted Diseases?
The answer to this question depends on which type of condom is used
and on which types of STDs.

Latex condoms provide great protection against most STDs. Polyurethane
condoms also provide protection against STDs, but it is still not
clear just how much. Lambskin or natural condoms, on the other hand,
don't protect against STDs.
Latex condoms are best effective against diseases that travel in
bodily fluids (blood or semen). Such diseases are: HIV/AIDS,
hepatitis, chlamydia, gonorrhea. They are however much less effective
against Sexual transmitted diseases that are caused by organisms
living on the genitals. STDs such as herpes and HPV (human
papillomavirus) can get passed from one partner to another even if a
condom is used.

Condoms still significantly lessen your chance of a sexual transmitted disease.