An intimate tussle with your spouse or the cool side of a pillow? It may be shocking to some, but it seems like more married women are choosing the second option. A recent iVillage survey of wives aged 18-49 showed that most married women are only “somewhat happy” with their sex life and many prefer sleep over sex with their partner.

Roughly two thousand American wives were surveyed about their sex lives by iVillage and nearly 77 percent reported being “somewhat to extremely happy” with their sex life. Yet, another 63 percent also reported they’d rather sleep, watch a movie or read than have sex.

“I kind of look at this as sort of bad news,” therapist and relationships author Ian Kerner told “The Early Show.” “You may say you’re happy with your sex life, but in the end, if night after night you’re consistently picking a book, TV, Facebook, digital networking, any distraction that’s out there over intimacy with your partner, in the long run, your relationship could become vulnerable to things like infidelity. So you have to put sex at the center of your relationship.”

In response to the survey, various sources have sited a number of possible causes such as  children and fatigue for married women’s low sex interest. Do you agree? And what’s the secret to keeping the sexual spark in a marriage?