Douching associated with pregnancy risk.

Women who douche frequently--and then become pregnant--appear more likely to have a low-birth-weight baby than women who don't douche, a new study shows.

Douching is a personal hygiene practice, but its health benefits remain unproved, says study coauthor Kevin Fiscella, a physician at the University of Rochester (N.Y.) School of Medicine.

In fact, some scientists link the practice to a vaginal infection that can arise when natural protective flora are killed off in the vagina (SN: 9/5/98, p. 158). Women with such infections have a higher risk of giving birth prematurely.

Other studies have suggested links between douching and ectopic pregnancy, a dangerous condition in which the fertilized egg implants outside the uterus. Douching may also increase incidence of infertility and of pelvic inflammatory disease, an infection within a woman's reproductive tract. The new study is the first to link douching with low-weight newborns.

Fiscella and his colleagues analyzed data collected from 4,665 women across the United States who had given birth before 1988. About half of the women douched regularly. In the December 1998 OBSTETRICS & GYNECOLOGY, they report that 9.7 percent of the women who douched gave birth to low-birth-weight babies, compared with 5.8 percent of women who didn't douche regularly.

To eliminate factors that might distort the results, the researchers accounted for differences in race, marital status, household income, smoking, alcohol consumption, and other lifestyle factors. Low birth weight was considered to be 5.5 pounds (2.5 kilograms) or less.

Frequency of douching mattered. Women who douched once a week or less were not significantly more likely to have a low-birth-weight baby than those who didn't douche at all. However, the 650 women in the study who douched two or three times a week were 40 percent more likely to deliver low-birth-weight babies than women who didn't douche. The 37 women in the study who douched daily showed 2.5 times the risk of those who didn't douche.

"This is based on statistics that are not perfect but which are the best [available]," says Albert G. Thomas, an obstetric gynecologist at Mt. Sinai Hospital in New York City. As such, the research "is a springboard for further studies."

Fiscella agrees that it's premature to suggest douching causes low birth weight in babies. "I look at this as an exploratory study," he says.

Some women may be douching early in their pregnancies, especially before they know they are pregnant, Fiscella says. Studies have suggested that bacteria from douching can enter the amniotic sac and affect a pregnancy.

Thomas counsels his patients not to douche. If they must, he suggests they avoid the middle of the menstrual month, a time when foreign bacteria can ascend from the vagina to internal organs.

The number of women who douche has decreased. A survey in 1995 found that 27 percent of U.S. women age 15 to 44 douched regularly, compared with 37 percent a decade earlier. In the 1995 survey, more than half of black women and 21 percent of white women reported douching.