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Vaginal Douching and Reduced

Donna Day Baird, PhD, Clanice R. Weinberg, PhD, Lynda F. Voigt, PhD, andJanet R. Daling, PhD Introduction tubal infertility found an association be- tween douching and infertility among Vaginal douching has been practiced both those with and those without prior throughout recorded history.' A wide diagnosis of pelvic inflammatory disease variety of douching preparations have but no increase in risk with increased been used: garlic and wine (noted in the frequency of douching. Fertility impair- Egyptian Papyrus of 1500 B.C. as a ment is a difficult medical problem to treatment for menstrual disorders2), di- study with standard epidemiologic meth- lute Lysol (advertised in the early 20th ods because only a self-selected minority century in the United States for regular of women with fertility problems seek feminine hygiene and for contraception'), treatment.26 To avoid the problems inher- and water and vinegar (commonly used ent in studying infertility patients, we today35). Historically, the medical commu- compared the fertility of douchers and nity recommended douching for treat- nondouchers by collecting information on ment of specific gynecologic conditions6,7 the number of months parous women but was divided about the efficacy and required to become pregnant. This method safety of regular douching as a hygiene of studying fertility in women who are practice among healthy women.819 able to conceive27 has been used previ- Vaginal douching remains a common ously to investigate effects of such factors practice among women in the United as oral contraceptive use,28 cigarette smok- States. In a national survey conducted in ing,29'30 and occupational exposures.31'32 1988, 37% of women between the ages of The method will tend to underestimate an 15 and 44 years reported douching; 18% adverse effect of douching on fertility douched at least once a week.'0 Black because sterile women are excluded by women were about twice as likely to design. as White women (67% vs 32%), and those who did tended to douche more frequently. Methods Douching may not be benign. It has We compared the monthly probabil- been linked to increased risk of chlamydia ity of conception for douchers and non- infection,""2 pelvic inflammatory dis- douchers in married, parous women. The ease,4'0">I7 and ectopic pregnancy5"120 (but see Phillips et al.2'). Independent Donna Day Baird and Clarice R. Weinberg are associations were demonstrated even in with the Division of Intramural Research, studies that controlled for the reason for National Institute of Environmental Health douching and for sociobehavioral corre- Sciences, Research Triangle Park, NC. Lynda lates including sexual behavior.5"5 Re- F. Voigt and Janet R. Daling are with the and Department of Epidemiology, School of Public ports linking douching to vaginal Health and Community Medicine, University cervical cancer raise further concerns of Washington, Seattle. about the safety of the practice.22-24 Requests for reprints should be sent to A relationship between douching Donna Day Baird, PhD, Epidemiology Branch, and reduced a common sequela MD A3-05, National Institute of Environmen- fertility, tal Health Sciences, PO Box 12233, Research ofboth clinical and silent pelvic inflamma- Triangle Park, NC 27709. tory disease, has been addressed in only This paper was accepted November 1, one report.25 This case-control study of 1995.

June 1996, Vol. 86, No. 6 Douching and Fertliy women studied were controls from a Cumulative Percent Pregnant population-based case-control study of infertility conducted in King County, Cumulative Percent Pregnant Washington.33 Married mothers were se- by Frequency of Douching lected from birth certificate files matched to cases on race, age (within 5 years), census tract, and gravidity at the time of 100 the attempt. Of the women selected, 1026 (74%) were interviewed. 90- Women who were under the age of 18 years (n = 9), who had diabetes (n = 9), or who were on medication for seizures 80- (n = 6) were excluded. No meaningful time to pregnancy could be derived for 133 additional women, most of whom E~ 70 reported that they conceived while using contraception. Because the detailed ques- tions from which we derived our douching 60- categories were not included in the first a) few interviews, another 29 women were 0.- excluded. The final sample for analysis consisted of 840 women. Data on time to pregnancy, douch- o 40- ing, and other factors potentially related a) to reduced fertility were obtained retro- 0. spectively in a structured interview con- 30 -0-never douche (517) ducted in each respondent's home. Time to pregnancy was ascertained by collect- 20-&- .2/year(145) ing data on the number of months of 20- unprotected intercourse required to con- > 2/year, < 1/week (155) ceive. Women who reported having planned their indexpregnancywere asked, 10 - - > 1 /week (23) "How long (in months) were you trying to become pregnant?" Women with "un- planned" were asked when 1 01 1112 they stopped using before 1 2 3 4 5 67 8 9 the index pregnancy. Douching data were derived from questions about douching Number of Months without frequency at 1, 2, 3, 4, and 5 years prior to Contraception conception of the index pregnancy. At interview, respondents reported one of four douching frequencies for each of the FIGURE 1-Unadjusted cumulative percentage pregnant each month for women five time periods: (1) never douched, (2) In four groups determined by their frequency of douching. douched no more than twice a year, (3) douched more than twice a year but no more than once a week, or (4) douched more than once a week. The five numbers sure to ; history of pelvic soda, cocoa, and alcohol intake; and prior representing douching frequencies for the inflammatory disease, including postdeliv- recreational drug use, including mari- 5 years prior to conception were averaged ery infection; endometriosis; ovarian cysts; juana, cocaine, LSD, speed, and "other"). and rounded to the nearest whole num- sexually transmitted diseases; and body These life-style variables also were col- ber, and the corresponding category was mass index), reproductive factors (any lected from each woman for her spouse. assigned as the douching variable used in prior use of oral contraceptives, use of Most variables were measured as of the the analyses presented here. A second oral contraceptives as last method of beginning of eachwoman's noncontracept- variable based on the four-level douching contraception, any prior use of an intra- ing time period, but the following were frequency for the year closest to the time uterine device, pregnancy history, age at measured as of the time just before when each woman began attempting first , number of sexual conception: family income, education, pregnancy showed similar associations partners, frequency of sexual intercourse, body mass, usual length, (data not shown). and breast-feeding a child born before the regularity of menstrual cycle length, fre- Other factors potentially related to index pregnancy and continuing to do so quency of sexual intercourse, number of fertility included the following: demo- during at least part of the time to prior sexual partners, number of ciga- graphic factors (age, race, marital status, pregnancy), and life-style factors (smok- rettes smoked per day, and monthly education, and family income), self- ing status and number of cigarettes coffee, tea, soda, cocoa, and alcohol reported medical factors (prenatal expo- smoked per day; monthly coffee, tea, intake.

June 1996, Vol. 86, No. 6 American Journal of Public Health 845 Baird et al.

ratios, calculated from the multivariate TABLE 1-Prepregnancy Characteristics of 840 Women, by Their Practice of model, provide a measure ofthe degree to Vaginal Douching during the 5 Years before the Index Pregnancy which a factor is independently associated with fecundability (analogous to risk ra- Douchers Nondouchers tios in studies of chronic diseases). For (n = 178), No. (%) (n = 662), No. (%) P example, the fecundability ratio associ- ated with douching would be 0.5 if Demographic factors douchers were half as likely as nondouch- Age,y NS ers to become pregnant in each noncontra- <20 5 (3) 15 (2) cepting month. Female factors were mod- 20-24 50 (28) 169 (26) eled first. None of the several male factors 25-29 93 (52) 328 (50) 30-34 24 (13) 137 (21) that were subsequently modeled changed 35+ 6 (3) 13 (2) the relationship between douching and Race (non-White) 16 (9) 39 (6) NS fecundability, so they were dropped in Family income, $ NS further analyses. Heterogeneity of effect < 15 000 21 (12) 116 (18) 15 000-30 000 97 (55) 325 (49) was tested by including cross-product > 30 000 59 (33) 217 (33) terms in the multivariate model. Education, y <.01 <12 6 (3) 10 (2) 12 48 (27) 135 (20) Resuls 13-15 70 (39) 226 (34) .16 54 (30) 291 (44) Times to pregnancy ranged from 1 Marital status (unmarried) 6 (3) 25 (4) NS month to more than 10 years; 13% of the women required more than a year to Medical factors conceive. Douching was reported by 38% Prenatal diethylstilbestrol exposure 2 (1) 15 (2) NS ofthe women. Seventeen percent douched Prescribed medications 5 (3) 21 (3) NS very rarely (no more than twice a year). History of pelvic inflammatory disease 8 (4) 28 (4) NS History of endometriosis 3 (2) 20 (3) NS The cumulative pregnancy rate varied by History of 9 (5) 52 (8) NS frequency ofdouching (Figure 1). Women History of sexually transmitted diseases 36 (20) 111 (17) NS who douched most frequently (more than Body mass index, kg/M2 NS once a week) had the lowest cumulative < 20.0 (thin) 69 (39) 224 (34) were still not 20.0-26.9 (average) 97 (54) 395 (60) pregnancy rate: 27% preg- . 27.0 (obese) 12 (7) 44 (7) nant after a year. Women who douched more than twice a year but no more than Reproductive factors once a week had only slightly higher Recent use of oral contraceptives 70 (40) 232 (35) NS cumulative pregnancy rates: 24% were Prior use of intrauterine device 42 (24) 126 (19) NS still not pregnant after a year. In contrast, Prior use of 14 (8) 38 (6) NS cumulative pregnancy rates were high for Menstrual cycle length, d NS <26 11 (6) 39 (6) women who never or rarely douched: only 26-31 89 (50) 371 (56) about 10% were still not pregnant after a >31 77 (44) 250 (38) year. Prior pregnancies NS Because of the similar cumulative None 85 (48) 345 (52) rates of women who never >1 93 (52) 317 (48) pregnancy Prior induced abortiona 20 (22) 66 (21) NS douched and women who rarely douched, Prior spontaneous abortiona 28 (30) 81 (26) NS these two groups were combined in Breast-feeding during time to pregnancy 5 (3) 22 (3) NS further analyses. They are referred to as Frequency of sexual intercourse, times/mo NS nondouchers. When the two remaining <8 52 (30) 187 (28) 8-17 95 (54) 390 (59) groups were combined as douchers, their >17 29 (16) 80 (12) unadjusted monthly probability of preg- Age at first sexual intercourse (< 18 yr) 55 (31) 146 (22) <.05 nancy (fecundability) was about 70% of No. lifetime sexual partners NS that for nondouchers (fecundability ra- 513 (78) 1-4 131 (74) tio = 0.68, 95% confidence interval 5-9 35 (20) 89 (13) 10-15 6 (3) 36 (5) [CI] = 0.58, 0.80). Douchers were similar >15 6 (3) 22 (3) to nondouchers on most demographic, (Continued) medical, reproductive, and life-style fac- tors (Table 1). However, douchers did have less education and an earlier age at first intercourse than nondouchers. They To quantify the relationship between descriptive statistics and multivariate mod- also drank more coffee and were more douching and reduced fertility, we esti- eling. A discrete-time analog of the Cox likely to smoke cigarettes. Cigarette smok- mated the fecundability ratio, the ratio of proportional hazards model34 was applied ing was the only one of these characteris- the monthly probability of pregnancy for to the time to pregnancy data by means of tics that was also related to reduced douchers in comparison with that for macros developed by Wacholder35 for the fecundability. After adjustment for smok- nondouchers.m Data analysis included GLIM program.36 Adjusted fecundability ing and seven other factors found to be

6 846 American Journal of Public Health June 1996, Vol. 86, No. Douching and Fertlity related to fecundability (frequency of intercourse, age, menstrual cycle length, TABLE 1-Continued breast-feeding, oral contraceptive use as last method of birth control, history of Douchers Nondouchers ovarian cysts, and history of LSD use), (n = 178), No. (%) (n = 662), No. (%) P douchers still had about 70% of the fecundability ofnondouchers (fecundabil- Ufe-style factors ity ratio = 0.69, 95% CI = 0.58, 0.80). <.05 The association between douching Never 99 (56) 405 (61) and reduced fecundability varied signifi- Past 20 (11) 102 (15) (23) cantly with age of the woman (P < .05). Current 59 (33) 155 Coffee intake, cups/d <.05 As shown in Table 2, the adverse effect of 0 60 (34) 255 (39) douching was greatest in young women <1.0 28 (16) 89 (13) (fecundability ratio = 0.50 for women 18 1.0-2.9 38 (21) 185 (28) to 24 years of age). Little reduction in > 3.0 52 (29) 110 (16) Alcohol intake, drinks/d NS fecundability was seen for women 30 years 0 53 (30) 249 (38) of age and olderwho douched (fecundabil- <1.0 76 (43) 279 (42) ity ratio = 0.94). 1.0-2.9 42 (24) 120 (18) Douching was associated with re- 2 3.0 7 (4) 13 (2) duced fecundability regardless of the Recreational drug use 98 (55) 323 (49) NS UseofLSD 20(11) 71 (11) NS reasons given for douching or the re- ported methods of douching (Figure 2). Note. Because of missing data, sums do not always equal totals. After covariates had been controlled, the aAmong gravid women. fecundability ratios were similar for women who douched for reasons of cleanliness or habit and for women who TABLE 2-Reduced Fecundablilty of Douchers as Measured by the Adjusted douched because of infection or odor TABLE 2-Reduced Fecundability of Douchers as Measured by the Adjusted (possibly indicative ofbacterial vaginosis). Fecundability Ratio, by Age Group Nor was the reduction in fecundability to women who douched "imme- confined Age Group, y No. Douchers Fecundability Ratioa 95% Confidence Interval diately" after sexual intercourse. Women were asked what douching preparation 18-24 52 0.50 0.35, 0.70 they usually used. Water only, water and 25-29 90 0.71 0.57, 0.90 vinegar, and commercial showed 30-39 27 0.94 0.68,1.31 similar reductions in fecundability. Use of a douche and use of a disposable aAdjusted for frequency of sexual intercourse, use of oral contraceptives as last method of birth bag control, history of ovarian cyst, menstrual cycle length, breast-feeding during time of trying to douche container were both associated conceive, cigarette smoking, and history of LSD use. with reduced fecundability, but the asso- ciation was somewhat stronger for women using the disposable douche container. These patterns were not substantially married, parous women. This relationship ity because women who use douching for altered (data not shown) after the age- would be expected if douching were done contraception may be relatively subfertile related differences in effect had been to alleviate vaginal symptoms of genital (an ineffective method of contraception controlled. infections (the infections being the real appears to work for them, so they con- To investigate a dose response, we cause of infertility). However, this poten- tinue to use it) or because douching compared the fecundability of very fre- tial bias may not explain our results. First, immediately after intercourse might possi- quent douchers (more than once per national survey data on why women bly acutely reduce sperm transport. The week; n = 23) with that of less frequent douche indicate that most douchers start women in our sample were not asked douchers (more than twice per year but douching when they are young and do so specifically whether they douched for no more than once per week; n = 146) for nonmedical reasons.3'37 Second, women contraception, but they were asked stratified by age. A dose response emerged in our study were asked their reasons for whether they douched after intercourse. for women under 25 years of age (fecund- douching. Excluding from analysis the The majority did not, and douching was ability ratio = 0.16, n = 6, for very fre- 17% of our sample who reported ever related to reduced fertility regardless of quent douchers; fecundability ratio = 0.58, douching because of infection or odor (a the timing (Figure 2), indicating that n = 46, for less frequent douchers). No symptom ofundiagnosed bacterial vagino- factors other than these contraception- dose dependency was apparent for older sis) did not change our results. Finally, related issues account for the observed women. douchers in our study were not more association. likely than nondouchers to report a The issue of uncontrolled confound- Discussion histoxy of genital infections (17% and ing has been raised regarding reported 20%, respectively). associations between douching and pelvic We observed a significant association Although douching is not an effective infection and tubal pregnancy. It is also a between vaginal douching and reduced method of contraception, it might be concern in this study. Although everyone fertility (P < .001) in a sample of 840 associated with somewhat reduced fertil- in our sample was married and parous,

June 1996, Vol. 86, No. 6 American Journal of Public Health 847 Baird et al.

pregnancy history month by month start- ing with age at first sexual intercourse, Fecundability Ratio some reporting errors in the time to 03 0.5 0.7 1.0 2.0 3.0 pregnancy data are inevitable. Therefore, I I I we conducted a confirmatory analysis with a dichotomous measure less susceptible to Reason for Douching misclassification. Women were catego- rized as infertile if they required more infection/odor (29) than a year to conceive, the standard clinical definition of infertility. The odds cleanliness/habit (140) ratio (OR) for infertility associated with douching was estimated by means of logistic regression to control for the same Timing of Douching covariates used in the fecundability analy- sis. A strong association again emerged, -4 before sex (10) with douchers being nearly three times more likely than nondouchers to experi- after sex (56) ence clinical infertility (OR = 2.9, 95% CI = 1.9, 4.6). Misclassification of douching fre- neither (103) quency is also unlikely to account for the observed association. Women were asked Preparations to report their frequency of douching at five points in time: 1, 2, 3, 4, and 5 years water (30) before conception. When analyzed sepa- rately, douching at each of the five time points was associated with significant water & vinegar (59) reduction in fertility. Moreover, when these data were used to derive a variable commercial (72) that best reflected each woman's douch- ing status at the time she started trying to Device conceive, this measure of douching was also significantly related to reduced fertil- ity. This indicates that subfertile women douche bag (120) began douching before they were aware of a fertility problem, not in response to it. disposable (45) If douching does reduce fertility, the mechanism for such an effect is unclear. i I I I I I I I I I Absorption of chemicals in douching 03 0.5 0.7 1.0 2.0 3.0 preparations is a concern,38 but few data are available. One study found that Note. The numbers in parentheses represent the number of douchers in each group. The frequent use of medicated con- comparison group in all cases was nondouchers (women who douched no more than twice a taining povidone-iodine can result in year; n = 649). As an example, the women who douched because of infection or odor had 61% of the fecundability of nondouchers; likewise, women who douched for cleanliness or out of habit iodine overload,39 and a case of disturbed had similarly reduced fecundability in comparison with nondouchers. thyroid function has been reported in a breast-fed infant due to maternal use of povidone-iodine-containing douches.40 In FIGURE 2-Adjusted fecundability ratios (with 95% confidence Intervals) for our data, we found no evidence that women with different douching habits. groups of commercial preparations produced any greater reduction in fertility than a combi- nation of water and vinegar prepared at the douchers in our study tended to be evaluation was made of the participants home. Even water alone was associated less well educated than nondouchers, just or their spouses, so we were unable to with significant reduction in fertility. This as seen in national samples. However, control for poor semen characteristics or suggests that the mechanical process of when we controlled for this potential documented medical problems in the douching per se may have adverse effects. confounder in analysis, it did not change women. Cramer et al. suggested that douch- the observed association between douch- Information bias from retrospec- ing may increase the risk of endometriosis ing and reduced fertility. Also, controlling tively collected time to pregnancy data is by increasing retrograde .41 for any of the other many variables another concern. The women in this study Few women in our sample had been collected in the extensive personal inter- were interviewed 1 to 16 years after they diagnosed with endometriosis, and douch- view did not change the association. began trying to conceive (median of 4 ers were not more likely to report being However, all variables were self-reported, years). Even though the interviewers diagnosed with the condition than non- including the medical data. No clinical recorded each woman's contraceptive and douchers (2% of douchers vs 3% of

848 American Journal of Public Health June 1996, Vol. 86, No. 6 Douching and Fertility nondouchers). However, undiagnosed en- ectopy and more frequent changes in after reading an earlier version of the manu- dometriosis could be a mediating factor. sexual partners). script. Alternatively, simply the introduction of If the adverse effect of douching is fluid into the uterine cavity might initiate mediated by infections with sexually trans- References uterine or tubal changes that interfere mitted organisms, we would expect douch- 1. Finch BE, Green H. Contraception through with implantation. ing to show little association with reduced theAges. Springfield, Ill: Charles C Thomas fertility in women with little or no expo- Publisher; 1963. Other data indicate that infectious 2. Whitson GE, Ellis FA. Vaginal douches. agents might mediate an association be- sure to sexually transmitted organisms. SDJMedPharmacol. 1948;1:217-226. tween douching and reduced fertility, We cannot test this hypothesis with data 3. Stock RJ, Stock ME, Hutto JM. Vaginal including several epidemiologic studies from our study. Data on numbers of sex douching: current concepts and practices. partners were collected in categories such Obstet Gynecol. 1973;42:141-146. that have linked douching to increased 4. Forrest KA, Washington AE, Daling JR, risk of pelvic inflammatory disease.4'10'1S'7 that monogamous women could not be Sweet RL. Vaginal douching as a possible Pelvic inflammatory disease generally identified, and biological samples to evalu- risk factor for pelvic inflammatory disease. arises from the spread of lower tract ate antibody titers were not collected. JNatlMedAssoc. 1989;81:159-165. Schwartz SM, et al. infections,42 and douching may enhance Only 3% of our sample reported chla- 5. Daling JR, Weiss NS, mydia or infections, and con- Vaginal douching and the risk of tubal the spread by mechanically propelling pregnancy. Epidemiology. 1991;2:40-48. pathogens to the or changing the trolling for this had little effect on the 6. West C. Lectures on the Diseases of Women. vaginal environment.43 Consistent with relationship. Ability to identify monoga- Philadelphia, Pa: Blanchard & Lea; 1858. mous women (whose partners were also 7. Webster JC. A Text-Book of Diseases of the latter, douching has been found to Women. Philadelphia, Pa: WB Saunders affect numbers of vaginal flora"4 and, monogamous) and information on infec- antibody titers will be Co; 1907. specifically, to reduce vaginal lactobacilli, tion history from 8. Fothergill WE. The bad habit of vaginal the bacteria that defend against genital useful in future studies. douching. BMJ. 1918;1:445-446. were pre- vaginal production of The women in this study 9. Barnes J. Uses and abuses of pathogens by their normal White White, 2% Black, douching. Practitioner. 1960;184:668-670. infertility is a dominantly (93% hydrogen peroxide.45 Tubal 2% Asian, and 3% other), and they were 10. Aral SO, Mosher WD, Cates W Jr. Vaginal inflamma- douching among reproductive age women documented sequela of pelvic better educated (40% had college educa- tory disease (poor gamete transport re- in the United States: 1988. Am J Public tions) than the US population as a whole. Health. 1992;82:210-214. sults from scarring of fallopian tube Consistent with these differences, only 11. Stergachis A, Scholes D, Heidrich FE, et epithelium).4" It also has been suggested 21% of our sample douched regularly, as al. Selective screening for Chlamydia tracho- that pelvic inflammatory disease might compared with 37% of the US population matis infection in a primary care popula- reduce fertility by interfering with implan- tion of women. Am J Epidemiol. 1993;138: (or 32% of the US White population).'0 143-153. tation through some immune response to Among those who douched, frequency of 12. Scholes D, Stergachis A, Heidrich FE, et current or past uterine infection.47 douching was also lower (13% douched al. Vaginal douching and risk of C. tracho- Rates of self-reported, physician- more than once a week, in comparison matis infection. Am J Epidemiol. 1995;141: diagnosed pelvic inflammatory disease S24. Abstract. with 29% of douchers in the US popula- 13. Neumann HH, DeCherney A. Douching were very low for both douchers and tion). Our sample was also selected on and pelvic inflammatory disease. N Engl J nondouchers in this study (4% of both being able to conceive; irreversible infertil- Med. 1976;295:789. groups). Controlling for pelvic inflamma- ity problems, such as bilateral tubal 14. McGregor JA, Spencer NE, French JI, et tory disease did not substantially change al. Psychosexual and behavioral risk factors occlusion, were not represented. Thus, if for acute salpingitis. In: Proceedings of the the observed association between douch- douching does have adverse effects, these Sixth International Meeting of the Interna- ing and reduced fertility, suggesting that effects will be magnified in a more tional Society for STD Research; July this variable was not a mediator in our representative group ofwomen. 31-August 2, 1985; Brighton, England. sample. However, subclinical pelvic infec- of douching is 15. Wolner-Hanssen P, Eschenbach DA, Further study vaginal Paavonen J, et al. Association between tion probably is more common than needed, including investigation of mecha- vaginal douching and acute pelvic inflam- diagnosed disease,d and we have no data nisms by which douching might reduce matory disease. JAMA. 1990;263:1936- to examine its effect on the observed fertility. Douching is viewed by many 1941. association. women in the United States, especially 16. Aral SO, Mosher WD, Cates W Jr. Self-reported pelvic inflammatory disease The increased risk associated with Black women, as an accepted feminine in the United States, 1988.JAAL4. 1991;266: douching in young women relative to hygiene practice. Given the reported 2570-2573. older women in our study may be an associations with pelvic infections, tubal 17. Scholes D, Daling JR, Stergachis A, et al. artifact of our methodology of using birth pregnancies, and infertility, women need Vaginal douching as a risk factor for acute have pelvic inflammatory disease. Obstet Gyne- certificates as the sampling unit. Women to be informed that douching may col. 1993;81:601-606. who attempt pregnancy at an older age adverse effects. O 18. Chow W-H, Daling JR, Weiss NS, Moore are less likely than younger women to DE, Soderstrom R. Vaginal douching as a conceive and give birth, and this selective potential risk factor for tubal ectopic Am J Obstet 1985;153: exclusion might make it more difficult to Acknowledgments pregnancy. Gynecol. Data collection was supported by a contract (1 727-729. see a relationship between douching and NO1 HD 02821) with the National Institute of 19. Chow JM, Yonekura ML, Richwald GA, reduced fertility among the older partici- Child Health and Human Development. Greenland S, Sweet RL, Schachter J. The pants in our study. Alternatively, the We wish to thank Mike Day, John Hogan, association between Chlamydia trachoma- tis and a matched-pair, higher risk in the young could reflect their Robert McConnaughey, and N. Beth Ragan : for data processing. Willard Cates, Jr., Beth case-control study. JAAfA. 1990;263:3164 possibly increased susceptibility to sexu- Gladen, Claude Hughes, Charles Livengood, 3167. ally transmitted diseases (e.g, younger Polly Marchbanks, Andrew Rowland, and 20. Kendrick JS, Atrash HK, Strauss LT, women have higher rates of cervical Allen Wilcox provided helpful suggestions Gargiullo PM. Vaginal douching and risk

June 1996, Vol. 86, No. 6 American Journal of Public Health 849 Baird et al.

of ectopic pregnancy among black women. associated with delayed conception. JAMA. FederalRegister. October 13,1983;48:46693- Am JEpidemiol. 1995;141:S25. Abstract. 1985;253:2979-2983. 46729. 21. Phillips RS, Tuomala RE, Feldblum PJ, et 30. Howe G, Westhoff C, Vessey M, Yeates D. 39. Mahillon I, Peers W, Bourdoux P, Ermans al. The effect of cigarette smoking, Chia- Effects of age, cigarette smoking, and other AM, Delange F. Effect ofvaginal douching mydia trachomatis infection, and vaginal factors on fertility: findings in a large with povidone-iodine during early preg- douching on ectopic pregnancy. Obstet prospective study. BMJ. 1985;290:1697- nancy on the iodine supply to mother and Gynecol. 1992;79:85-90. 1700. fetus. Biol Neonate. 1989;56:210-217. 22. Peters RK, Thomas D, Hagan DG, Mack 31. Rachootin P, Olsen J. The risk of infertility 40. Rakover Y, Adar H. Thyroid function TM, Henderson BE. Risk factors for and delayed conception associated with disturbances in an infant following mater- invasive cervical cancer among Latinas and exposures in the Danish workplace. J nal topical use of polydine. Harefuah. non-Latinas in Los Angeles County. JNCI. Occup Med. 1983;25:394-402. 1989;116:527-529. 1986;77:1063-1077. 32. Rowland AS, Baird D, Weinberg CR, 41. Cramer DW, Wilson E, Stillman RJ, et al. 23. Gardner JW, Schuman KL, Slattery ML, Shore DL, Shy CM, Wilcox AJ. Reduced The relation of endometriosis to menstrual Sanborn JS, Abbott TM, Overall JC. Is fertility among women employed as dental characteristics, smoking and exercise. vaginal douching related to cervical carci- assistants exposed to high levels of nitrous JAM4. 1986;255:1904-1908. noma? Am J Epidemiol. 1991;133:368-375. oxide. NEnglJMed. 1992;327:993-997. 42. Westrom L. Pelvic inflammatory disease: 24. Brinton LA, Nasca PC, Mallin K, et al. 33. Daling JR, Weiss NS, Metch BJ, et al. bacteriology and sequelae. Contraception. Case-control study of in situ and invasive Primary tubal infertility in relation to the 1987;36:111-128. carcinoma of the vagina. Gynecol Oncol. use of an intrauterine device. NEnglJMed. 43. Rosenberg MJ, Phillips RS. Does douching 1990;38:49-54. 1985;312:937-941. promote ascending infection? J Reprod 25. Mueller Med. 1992;37:930-938. BA, Luz-Jimenezx M, Daling JR, 34. Weinberg CR, Wilcox AJ, Baird DD. 44. Onderdonk AB, Delaney ML, Hinkson et al. Risk factors for tubal infertility: Reduced fecundability in women with influence of PL, DuBois AM. Quantitative and qualita- history of prior pelvic inflam- prenatal exposure to cigarette smoking. tive effects of douche preparations on matory disease. Sex Transm Dis. 1992;19: AmJ EpidemioL 1989;129:1072-1078. vaginal microflora. Obstet Gynecol. 1992;80: 28-34. 35. Wacholder S. Binomial regression in GLIM: 333-338. 26. Hirsch MB, Mosher WD. Characteristics estimating risk ratios and risk differences. 45. Hillier SL. The vagina as an ecosystem. In: of infertile women in the United States and Am JEpidemiol. 1986;123:174-184. Proceedings of the Ninth International their use of infertility services. Feriil Stenil. 36. Payne CD, ed. The GLIM System Release Meeting of the International Society for 1987;47:618-625. 3.77 Manual. Oxford, England: Numerical STD Research; October 6-9, 1991; Banff, 27. Baird DD, Wilcox AJ, Weinberg CR. Use Algorithms Group; 1986. Alberta, Canada. of time to pregnancy to study environmen- 37. Chacko MR, McGill L, Johnson TC, Smith 46. Moore DE, Cates W Jr. Sexually transmit- tal exposures. Am J Epidemiol. 1986;124: PB, Nenney SW. Vaginal douching in ted diseases and infertility. In: Holmes KK, 470-480. teenagers attending a Mardh P-A, Sparling PF, et al., eds. 28. Linn S, Schoenbaum SC, Monson RR, clinic. JAdolesc Health Care. 1989;10:217- Sexually Transmitted Diseases. 2nd ed. New Rosner B, Ryan KJ. Delay in conception 219. York, NY: McGraw-Hill International for former 'pill' users.JAMA. 1982;247:629- 38. Vaginal drug products for over-the-counter Book Co; 1990:763-769. 632. human use; establishment of a monograph; 47. Morell V. Attacking the causes of "silent" 29. Baird DD, Wilcox AJ. Cigarette smoking advance notice of proposed rulemaking. infertility. Science. 1995;269:775-777. News.

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