The unique programme allows the women to have access to files on their partners, which include detailed admissions of their offences, made during therapy.
The women are also given reports on their partners prepared for the police by psychologists, giving an assessment of the likelihood that they will reoffend.
The Home Office has given the project "Pathfinder" status, meaning that it will be developed as a blueprint for other similar schemes across Britain.
Senior probation officers set up the scheme after realising that many wives of sexual abusers were prepared to forgive their partners rather than break up their family.
Chris Wilson, manager of the Thames Valley Project, based in Oxfordshire, said it was vital that women having to make such a decision should be able to make an informed choice.
"It came as a shock to me that so many sex offenders had remained with their partners, he said. "We are dealing here with real people and not media monsters. These women know and love these men and despite the abuse they know there are qualities and good parts to them."
Mr Wilson said there was a danger that some of the women may have been convinced by their partners that there was no chance of the offences ever being repeated.
"The women are told by the men that it was a one-off, that they were under a lot of stress at work," he said. "Our view was that if a woman makes a decision to stay with an abuser then that should be an informed choice."
One of the women on the course said: "The group has helped me to understand my partner's offence. Before I came to the group I did not have any understanding about his offending."
The Thames Valley Project, which is run by the Oxfordshire, Buckinghamshire and Berkshire Probation Services, has enjoyed great success applying a group therapy programme to offenders.
Of the first 150 sex offenders to be treated, only six have re-offended within three years.
The information that emerges over an intense 70 hour-programme is used to compile the offender's "personal sexual assault cycle", setting out the "fantasy" and "planning" stages to their attacks.
The cycle helps the offender to keep their behaviour in check by recognising these warning signals when they reoccur.
Mr Wilson said: "Because it's a cycle you can get off that cycle. If you know the process then you can exit."
But as well as knowing details of their partner's "personal sexual assault cycle", women will also want to know their likely risk of further attacks.
Head of the project, Mary Faux, said that each sex offender was made to fill in questionnaires comprising nearly 1,000 questions, designed to examine their behaviour in a series of given situations.
The answers are psychometrically tested to give an assessment of the risk of reoffending and the findings are passed to police.
As well as helping women to make an informed choice, the newly-established "Partners Project" also helps the women to draw support from each other. After first learning of the abuse, many women feel isolated and ashamed to speak to neighbours and friends. The group gives them the opportunity to share their fears and experiences with other women in a similar position.
One woman on the programme said: "I now recognise and am in touch with my own feelings. I don't feel so isolated as I did when I first started. The group has taught me a lot about myself and sex offenders."
Of the 20 women to have so far participated in the project, only one has decided to leave her partner on the basis of the information she has learnt.
She said: "I now feel strong and confident in myself and in what I want from life. I know that I don't want a paedophile for a partner."Reuse content