A high body mass index (BMI), indicating overweight or obesity, may not play a significant role in women’s sexual activity, researchers report.

“Obese and overweight women are just as sexually active as normal-weight women and need to be counseled similarly about their risks of unintended pregnancy and infection,” Dr. Bliss E. Kaneshiro told Reuters Health.

Kaneshiro, of the University of Hawaii in Honolulu, and colleagues base these findings on surveys from 6,690 women, 15 to 44 years old, who participated in the 2002 National Survey of Family Growth.

The group is representative of the women living in the U.S. at the time. Just over half were 30 to 45 years old and about 16 percent were 15 to 19 years of age, the researchers report in the journal Obstetrics and Gynecology.

Overall, 54 percent of the women were of normal weight (BMI of less than 25). Another 25 percent were overweight (BMI between 25 and 30), and 21 percent were considered obese (body mass index than 30). Body mass index - the ratio of weight to height - is often used to classify subjects as under- or overweight.

Women in different weight groups were similar in age, cohabitation status, race, ethnicity, education, and total household income. A higher proportion of normal-weight women reported never having borne a child and a higher proportion of overweight and obese women reported having three or more children.

The investigators found no significant differences among the weight groups in sexual orientation, frequency of sexual intercourse, the number of current partners, age at first intercourse, the number of lifetime male partners, or the number of male partners in the previous year.

However, Kaneshiro’s group unexpectedly found that obese and overweight women, compared with normal-weight women, were more likely to report a history of intercourse with a male, even though they did not report an early initiation of intercourse.

The investigators suggest continuing research into the association between BMI and women’s sexual behavior as this association can affect the risk of unintended pregnancy and sexually transmitted diseases.

SOURCE: Obstetrics and Gynecology, September 2008.