Before pointing fingers or laying the blame, ask yourself -- and her -- why her affections have waned. There may be an array of reasons. These include physical problems, psychological issues, the constant presence of your children, stress and a negative self-image, according to neuroscience researcher Billi Gordon in the article "4 Essential Marital Bed Death Questions" on the Psychology Today website. While understanding your wife won't make the problem disappear, it can help you to better communicate with her and choose a road to follow. For example, if she says she wants you to stay away because she's gaining weight and is embarrassed about her body, you can help boost her confidence or work on showing her that you love her no matter what.

Major life changes may usher in differences in your wife's sexual needs and feelings. For example, if your wife recently gave birth, she'll need to wait until her doctor clears her at her six-week postpartum check-up before she can resume sexual activity, according to the U.S. Department of Health and Human Services' Office website. Even after the six-week mark, a woman may feel like sex simply isn't a priority as she cares for the baby and adjusts to her role as a mother. Likewise, women going through menopause may not feel sexual. A decrease in a woman's estrogen levels and vaginal dryness may make her shy away from intimacy. If her feelings persist, gently suggest that she see a doctor for a medical opinion.

It is possible that your wife simply doesn't enjoy sex. If this is the case, focusing on yourself and changing your sexual attitudes won't do much to change hers. Instead of agreeing with her and adopting her prudish ways, you can communicate your needs and discuss what she thinks the future holds for your relationship. If she says that she never wants to have an intimate relationship with you, evaluate whether this is something you can accept.

When your wife puts the brakes on intimacy, knowing that you can trust her is crucial. While not every seemingly prudish wife is having an affair, some do, according to Denise A. Donnelly, associate professor of sociology at Georgia State University, interviewed by Tara Parker-Pope in The New York Times article "When Sex Leaves the Marriage." Part of living with a prudish wife is believing that she is this way with everyone. Have an honest conversation with her. Although her answers may hurt, not knowing won't help and may drive a larger wedge between the two of you. Seeing a therapist who specializes in marriage and sex issues can help the two of you better understand your feelings.