Douching Raises Infection Risk, but Only for Women Without Bacterial Vaginosis
Women with symptoms of pelvic inflammatory disease (PID) who have douched recently are nearly twice as likely as those who have not practiced douching to have an upper genital tract disease, according to findings from a large, multisite clinical study.1 Douching is more common among women with bacterial vaginosis than among those without this condition, which has been suspected of facilitating the link between douching and upper genital tract inflammation (endometritis) or infection (chlamydia or gonorrhea). However, the association between douching and upper genital tract disease is statistically significant only among women who do not have bacterial vaginosis.
The study included women aged 14-37 attending 13 clinical sites (emergency departments, clinics and sexually transmitted disease units) in the eastern, southern and central United States in 1996-1999. Women were eligible to participate if they had signs of PID (discomfort for 30 days or more, organ tenderness during a pelvic examination, an excess number of white blood cells in vaginal secretions or cervical discharge). In addition to being screened for endometritis, upper genital tract infection and bacterial vaginosis, participants completed an interview that covered their background characteristics, douching habits and other factors related to the risk of upper genital tract disease. A total of 654 women were included in the analyses.
Women with endometritis or upper genital tract infection (roughly half of the cohort) were significantly more likely than those with neither type of disease to be younger than 20 (30% vs. 20%) and black (79% vs. 63%), and to smoke (49% vs. 40%) or use cocaine (5% vs. 2%). They were less likely than others to have any postsecondary education (18% vs. 30%) and to report a history of PID (26% vs. 35%).
Roughly two-fifths of participants had douched in the month before they enrolled in the study. In initial analyses, women who had douched more than once a month were significantly more likely than those who had not douched at all to have upper genital tract disease (odds ratio, 1.6). Women who had douched within the previous six days also had increased odds of disease, when compared with those who had not douched (1.8). The reason that women douched, the product used and the frequency of douching among women who had douched recently were not associated with the risk of endometritis or upper genital tract infection.
When the researchers used logistic regression to adjust for background and other risk factors (including a history of PID, having a new partner, smoking and using cocaine), women who had douched within the past six days retained an elevated risk of upper genital tract disease (odds ratio, 1.7). The odds were also raised for those who had douched more than once in the previous month (1.5), but the increase was only marginally significant. Because nationally representative survey data indicate that black women are more likely than white women to douche, the researchers performed separate analyses to measure the association between douching and upper genital tract inflammation or infection for black women only. Resulting odds ratios were similar to those for the overall cohort, but they did not achieve statistical significance.
Some 345 women had bacterial vaginosis, and 51% of them douched, a significantly higher proportion than found among women without this condition (28-36%). Contrary to the investigators' expectations, douching was not significantly associated with upper genital tract disease among those with bacterial vaginosis. However, among the remainder of the cohort, women who had douched within the past month and those who had douched within the past six days were twice as likely as those who had not douched to have an inflammation or infection (odds ratios, 1.8 and 2.3, respectively). Similarly, while douching was not associated with the risk of upper genital tract disease in women with gonorrhea or chlamydia, women with neither of these conditions had an increased risk if they had douched at all in the previous month (1.5), if they had douched more than once (2.4) and if they had douched recently (2.1).
Speculating as to why douching raises the risk of upper genital tract infection only in women without preexisting disease, the researchers suggest that "inciting upward bacterial movement" may initiate inflammation or infection but not exacerbate conditions that developed independent of douching. They conclude that their findings "add to the growing literature suggesting that douching might relate to PID."--D. Hollander
1. Ness RB et al., Douching and endometritis: results from the PID Evaluation and Clinical Health (PEACH) Study, Sexually Transmitted Diseases, 2001, 28(4):240-245.