Attractive young man carrying his pretty girlfriend and kissing. Mixed race couple in love outdoors in park. Image credit: iStock/jacoblund

Most teenagers will have sex before they enter their 20s, but do they know enough about being responsible when it comes to intercourse to protect them and their partners against sexually transmitted infections (STIs) and unplanned pregnancy?

A new report from the Center of Disease Control in the US revealed that around 40 per cent of teenagers will have sex before they turn 18, showing that there is very little that can be done to stop them. However, teaching them about contraception is the best way to ensure they are safe, especially as the research found a worrying rise in the use of the pull-out method.

The study found that 99.4 per cent of teenage girls with sexual experience had used some type of contraception, with 81 per cent saying they used protection the first time they had sex. When it came to most recent sexual encounters, 90 per cent had used some form of contraception.

While 97 per cent of the teen girls said they had used condoms, a worrying 60 per cent said they had used the pull-out method. This can put them at risk of contracting STIs and could still mean getting pregnant due to the unreliable nature of this method.

While the chances of getting pregnant are reduced if you use the pull-out method perfectly, it's almost impossible to do this right. Even if you avoid ejaculation until you have pulled-out, sperm can still have been released earlier during intercourse.

If the pull-out method is coupled with another form of contraception, such as the pill - which 56 per cent of teenage girls have tried - it is a lot more effective at reducing the chances of pregnancy. However, this method suggests that condoms aren't be used, meaning there is an increased chance of catching STIs.

When you consider the fact that condoms are around 98 per cent effective as a form of contraception, offering protection against pregnancy and infections, they could very well be the best option for teens.