Even in relationships in which the decision to use the withdrawal method is mutual, it is often a decision made based on the man's pleasure, not the woman's.
She added that condoms and the withdrawal method were the more common forms of contraception because these needed less preparation as compared to the pill, for example.
If a recent debate on www.mumsnet.com is anything to by, some women are choosing the risky withdrawal method over the much more reliable contraceptive pill.
There are some benzodiazepine withdrawal support forums on the internet that can help doctors and patients inform themselves about withdrawal methods and give emotional support.
One expert who wasn't involved with the study said the reasons that might lead a woman to choose the withdrawal method over something more reliable are complicated.