NEW YORK?- Women undergoing treatment for infertility may be less satisfied with their sex lives and have a greater risk of sexual dysfunction than women with normal fertility, a small study suggests.

Researchers found that among 119 women seen at their infertility clinic, 40 percent scored low enough on a standard questionnaire of sexual function to put them at "high risk" of sexual dysfunction. That compared with 25 percent of 99 fertile women who were used as a control group.

Specifically, the infertility patients reported more problems with desire and arousal; they did not differ from fertile women in physical symptoms like vaginal dryness or pain during sex. Nor did they report more difficulty reaching orgasm, according to findings published in the journal Fertility and Sterility.

The study cannot point to the reasons for the findings, according to the researchers, led by Dr. Leah S. Millheiser of Stanford University Medical Center in California.

Past studies, they note, have found both infertility and its treatment can negatively affect women's and men's emotional well-being or create marital tension. In addition, couples trying to conceive may eventually feel the pressures of "sex-on-demand," which can drain their satisfaction with their sex lives, the researchers say.

In this study, women with fertility problems had a lower average score when it came to rating their sex-life satisfaction. And 34 percent said they'd had a decline in satisfaction since their infertility diagnosis.

The findings are based on 119 women who had been referred to the Stanford infertility clinic and 99 sexually active women in the same age range who were recruited from the university gynecology clinic. Both groups were similar in terms of average weight, education levels and racial and ethnic makeup.

All of the women completed a standard questionnaire on female sexual function; scores lower than 26.5 are considered to denote a high risk of sexual dysfunction. The average score in the infertility group was 27.1, compared with 28.7 among fertile women.

Forty percent of women with fertility problems scored low enough to be considered high-risk, versus one-quarter of fertile women. Infertile women also tended to have intercourse less often -- an average of seven times per month, compared with just over nine times per month for fertile women.

"With this study," Millheiser and her colleagues write, "we hope to highlight infertility as a potential risk factor for sexual dysfunction."

They add that further studies that measure additional factors like depression, marital problems and male partners' sexual function are needed.