More than half of U.S. women ages 35 and over are having less sex during menopause than before menopause, according to a new survey.

And 36 percent of survey respondents, who are in committed relationships, said their partners are "upset" with the decrease in frequency, according to the Sex & Menopause Survey, commissioned by the company, Red Hot Mamas, and sponsored by Duramed Pharmaceuticals.

Not every woman's menopause is the same, according to the poll, which was conducted by Harris Interactive. Some women experience vasomotor symptoms such as hot flashes or night sweats, while others experience vaginal atrophy (vaginal narrowing or shrinkage), which can cause vaginal dryness and painful sex.

If left untreated over time, vaginal atrophy ultimately can lead to chronic sexual dysfunction and/or physically uncomfortable sexual experiences, the survey said.

Sixty percent of those polled reported openly discussing the symptoms of menopause with their partners and 67 percent said their partners understand the impact of menopause on their lives. But just 46 percent of respondents, however, reported discussing decreased frequency in sex as a symptom of menopause with anyone, including their partners.

The women's reluctance to discuss the sexual side effects of menopause was particularly disturbing to researchers.

"Women today, specifically the boomer generation currently entering or experiencing menopause, are much more open about their needs and seek information more than previous generations, so it's surprising to me that so many women would settle for a less than satisfying sex life as a result of menopausal symptoms," said Karen Giblin, founder of the Red Hot Mamas Menopause Management Educational Programs, in a press release.

Women who experienced vaginal atrophy are more likely to also report a decrease in frequency of sex, according to the survey, which found:

— Seventy-five percent of these women reported having less sex since entering menopause and 68 percent reported experiencing pain during active sex

— Eighty-eight percent of women who experienced vaginal atrophy said their symptoms are at least somewhat problematic

— Almost half (47 percent) of these women reported that they have avoided, made an excuse or stopped having sex altogether because of physical discomfort

— Fifty-one percent of those who reported experiencing symptoms of menopause reported that they experienced vaginal dryness. Of those, 79 percent reported the symptom as having an effect on their sex lives.

"If left untreated, over time, women will experience changes such as vaginal atrophy and dryness that can make physical intimacy uncomfortable, even painful. But they do not need to give up on sex altogether," said Dr. Murray A. Freedman, a gynecologist from Augusta, Ga. "Sadly, most women are unaware that these conditions are treatable."

Effective therapies include over-the-counter lubricants and FDA-approved hormone therapy, said Freedman.