June 19, 1996
19 Jun 1996: NIH Study: Among Women Who Want to Get Pregnant, Douching May Delay Conception
Douching may reduce a woman's chance of getting pregnant in a particular month by about 30 percent, according to a new study.
The study, published in the June issue of the American Journal of Public Health, showed that douching-practiced by many women to cleanse and deodorize the vaginal cavity -- is associated with a delay in pregnancy.
Donna Day Baird, Ph.D., epidemiologist of the National Instituteof Environmental Health, Research Triangle Park, N.C., and adjunct professor at the University of North Carolina School of Public Health, Chapel Hill, conducted the study with Clarice Weinberg, Ph.D., also of NIEHS, and colleagues at the University of Washington.NIEHS is the part of the federal National Institutes of Health that studies human health, including fertility, as it is impacted by environmental factors.
The authors studied 840 married women from Washington state who had stopped using contraception and eventually became pregnant. Those who douched, the researchers found, took longer to conceive than those who did not. The researchers looked at other personal and environmental factors such as smoking, alcohol intake and medical background but, even after adjusting for other factors that affect fertility, found that women who douched were less likely to conceive in any given month of trying.
The reduction in fertility associated with douching was stronger in young women, 18 to 24, in whom douching was associated with a 50 percent reduction in monthly fertility. The estimated reduction in month fertility was 29 percent in women who were 25 to 29,and 6 percent for women 30 to 39.
A 1988 national survey found 37 percent of women between 15 and44 douched, and 18 percent did so at least once a week. Blackswere twice as likely as whites -- 67 percent versus 32 percent-to douche and did so more often.
The researchers found that, among women who wanted to become pregnant,those who douched most frequently (more than once a week) had the lowest pregnancy rate: Twenty-seven percent were not pregnant after a year. In contrast, only 10 percent of those who never or rarely douched were still not pregnant after a year.
"In our data, we found no evidence that commercial preparations produced any greater reduction in fertility than a combination of water and vinegar prepared at home," Dr. Baird said. "Even water alone was associated with significant reduction in fertility.This suggests that the mechanical process of douching per se may have adverse effects."
Earlier research showed flushing the vagina with water and other liquids reduced the number of beneficial bacteria. Another investigation suggested that the practice might mechanically propel harmful bacteria and other organisms to the cervix, causing infection.
"Further study of vaginal douching is needed, including investigationof mechanisms by which douching might reduce fertility,"Dr. Baird wrote. "Douching is viewed by many women in the United States, especially black women, as an accepted feminine hygiene practice.
"Given the reported associations with pelvic infections,tubal pregnancies and infertility, women need to be informed that douching may have adverse effects."
Lynda F. Voight, Ph.D., and Janet R. Daling, Ph.D., of the University of Washington School of Public Health at Seattle collaborated in the research.
Environmental Health Sciences Mature - NIEHS Celebrates 30th Anniversary (http://www.niehs.nih.gov/news/newsroom/releases/1996/august19/index.cfm)
NIH-Supported Studies Show Potential Danger to Fetus from Expectant Mothers' Own Early Exposure to Lead (http://www.niehs.nih.gov/news/newsroom/releases/1996/june13/index.cfm)