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Adler et al. BMC Pregnancy and Childbirth 2013, 13:246http://www.biomedcentral.com/1471-2393/13/246

RESEARCH ARTICLE Open Access

Estimating the prevalence of obstetric fistula:a systematic review and meta-analysisA J Adler*, C Ronsmans, C Calvert and V Filippi

Abstract

Background: Obstetric fistula is a severe condition which has devastating consequences for a womans life. Theestimation of the burden of fistula at the population level has been impaired by the rarity of diagnosis and the lackof rigorous studies. This study was conducted to determine the prevalence and incidence of fistula in low andmiddle income countries.

Methods: Six databases were searched, involving two separate searches: one on fistula specifically and one onbroader maternal and reproductive morbidities. Studies including estimates of incidence and prevalence of fistula atthe population level were included. We conducted meta-analyses of prevalence of fistula among women ofreproductive age and the incidence of fistula among recently pregnant women.

Results: Nineteen studies were included in this review. The pooled prevalence in population-based studies was0.29 (95% CI 0.00, 1.07) fistula per 1000 women of reproductive age in all regions. Separated by region we found1.57 (95% CI 1.16, 2.06) in sub Saharan Africa and South Asia, 1.60 (95% CI 1.16, 2.10) per 1000 women of reproductiveage in sub Saharan Africa and 1.20 (95% CI 0.10, 3.54) per 1000 in South Asia. The pooled incidence was 0.09 (95%CI 0.01, 0.25) per 1000 recently pregnant women.

Conclusions: Our study is the most comprehensive study of the burden of fistula to date. Our findings suggest thatthe prevalence of fistula is lower than previously reported. The low burden of fistula should not detract from theirpublic health importance, however, given the preventability of the condition, and the devastating consequences offistula.

Keywords: Vesicovaginal fistula, Maternal morbidity, Systematic review

BackgroundThe World Health Organisation defines an obstetric fis-tula (referred to as fistula in the text below) as an ab-normal opening between a womans vagina and bladderand/or rectum through which her urine and/or faecescontinually leak [1]. Classifications of fistula vary, butthey generally include fistulae from obstetric causes in-cluding vesicovaginal fistula (VVF) and rectovaginal fis-tula (RVF). Fistulae have devastating consequences [2,3],particularly in low income countries where women haveless geographical and financial access to appropriate sur-gical care for repair. In high income countries they arealso devastating, but they are very rare and surgery torepair them occurs more rapidly.

* Correspondence: [email protected] School of Hygiene & Tropical Medicine, Keppel St, London, WC1E7HT, UK

2013 Adler et al.; licensee BioMed Central LCommons Attribution License (http://creativecreproduction in any medium, provided the or

In high income countries, fistulae are due to iatrogeniccauses; generally the result of radiation therapy and surgi-cal interventions [4]. In low income countries where ac-cess to intrapartum care may be restricted, fistulae areassociated with a prolonged or obstructed labour, mostcommonly occurring when a babys head becomes lodgedin the mothers pelvis cutting off blood flow to the sur-rounding tissues. Prolonged obstruction can cause the tis-sues to necrotise leading to fistula formation [2].Women with fistulae often experience horrific or diffi-

cult associated conditions which stem either from thefistulae itself or from the prolonged or obstructed labourwhich caused it [3]. The most obvious consequences areincontinence, either urinary [3], faecal or both. The con-stant leakage of urine and faeces can also lead to damageto the vulva and thighs [2]. Fistulae are linked with socialostracisation [5] and marginalisation [6]. Many case

td. This is an open access article distributed under the terms of the Creativeommons.org/licenses/by/2.0), which permits unrestricted use, distribution, andiginal work is properly cited.
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series show high rates of divorce or separation [7,8], ab-sence of sexual intercourse [6,7], loss of fertility andamenorrhea [9,10] and depression [8,11] among womenwho have a fistula.Fistulae are thought to have the highest prevalence

where maternal mortality is high, but there is great un-certainty about the actual prevalence [2]. In the 2000Global Burden of Disease, Dolea and AbouZhar esti-mated that 0.08% of all births and 2.15% of neglectedobstructed labour births resulted in fistula [12]. Theseestimates came from four studies only, all of which werein sub-Saharan Africa and two were hospital-based. In2006, the WHO estimated that more than 2 millionyoung women throughout the world live with untreatedfistula, and that between 50,000 and 100,000 newwomen are affected each year [1]. These statistics origi-nated from countries rapid needs assessments and phy-sicians reports, mostly available in the grey literature,and not from epidemiological studies using robust de-sign, and almost none include a denominator.In 2007, Stanton and colleagues wrote a paper [13] on

the challenges of quantifying fistula. They describedthree types of publications reporting on frequency, inci-dence or prevalence of fistula. The first category of pa-pers relied on secondary and tertiary citations (many ofwhich culminated in personal communications) and re-ported the number of patients treated without denomi-nators. The second type of publications relied on

Cross-sectional and cohort studies with hospital basedrecruitment

den

YesInclude

NoExclude

C

FistuClear

denominator andadequate follow

up?

YesInclude

YInc

Figure 1 Types of studies included in our analysis.

declarations made by the authors themselves, or on sur-geons estimates but the source of data was unclear.The third type of studies described methods and pro-vided appropriate denominators, but with varying de-grees of transparency. Stanton and colleagues were onlyable to find four papers in this third category [13].The aim of our review is to provide improved estimates

of the prevalence and incidence of fistula by broadeningthe search and including studies that may previously havebeen overlooked. Unlike previous reviews of fistula[12-14], we include studies that examine a broad spectrumof reproductive morbidity (including morbidity studieswhere fistula is but one of many outcomes studied) and/orwhere no cases of fistula were reported.

MethodsA two-stage systematic review was conducted in accord-ance with the STROBE guidelines (http://www.strobe-statement.org/) using free-text and subject headings inPubmed, Embase, Popline, Lilacs, WHOs Eastern Medi-terranean database, and African Index Medicus publisheduntil the end of 2012. The first stage targeted studies spe-cifically reporting on fistula in the title, abstract or subjectheadings, including search terms such as fistula, vesicova-ginal fistula, and VVF. The second stage aimed at identify-ing additional studies that examined postpartum andreproductive morbidity more broadly, whether or not fis-tula was specifically mentioned as a pathology. This search

Clearominator?

ross sectional and cohort community based studies

la studiesReproductive

morbidity studies

NoExclude

Include fistulaas morbidity?

YesNo

HavePhysician

Exam

eslude

NoExclude

Have Physician Examand include prolapse as

morbidity?

YesInclude

NoExclude
http://www.strobe-statement.org/http://www.strobe-statement.org/

Papers with informationon incidence and

prevalence 6

Found fromgeneral maternaland reproductivemorbidity studies

10

Final: 19 Studies

Found fromforward

searching andreference lists 10

Initial search 11,366

After removingduplicates 9130

Obtained for full text367

Figure 2 PRISMA diagram of studies.


included terms such as reproductive morbidity and mater-nal morbidity. A full search strategy is available upon re-quest. Only English terms were used in the search, butarticles were not excluded based on language.Reference lists were searched for additional articles.

Using Web of Science, all relevant articles were subjectedto forward citation searching to obtain further articles.As illustrated in Figure 1, the following study designs

were included: (i) cross-sectional or cohort studies of fis-tula with hospital based recruitment of pregnant or re-cently delivered women where the women were followedfor and examined at least 30 days after the end of preg-nancy and there was a clear denominator; (ii) cross sec-tional or cohort studies of prevalent or incident cases offistula in the community and (iii) cross sectional or co-hort studies of prevalent or incident cases of reproduct-ive morbidity in the community. Studies were onlyincluded if women were examined for the presence offistula in hospital and/or if a well trained provider per-formed a physical examination of the genital area. Mor-bidity studies not reporting or mentioning fistulae butincluding a robust design, a thorough physical exam ofthe genital area that reported cases of uterine prolapsewere assumed to have zero cases of fistula, as it was as-sumed that if fistula had been found it would have beenreported. Studies relying on womens self-reports wereexcluded because self-reports of reproductive morbidityhave been shown to be unreliable [13,15,16]. We ex-cluded studies that were conducted before 1990 or pub-lished before 1991. We included studies irrespective ofsample size but studies without a denominator were ex-cluded. If more than one paper provided results of thesame study population, data were first extracted fromthe article with the greatest amount of information,and supplementary data extracted from the other pa-pers if required.Data were extracted by a single author (AJA) using a

proforma and included information on region, study dates,study population, duration of fistula, type of fistula, riskfactors, associated complications and denominators,how fistula were ascertained, sampling technique, num-ber of women and number of deliveries. There are nogood tools for looking at study quality in cross-sectional studies, so study quality was assessed using amodified Ottawa-Newcastle score (http://www.ohri.ca/programs/clinical_epidemiology/oxford.asp).The studies reported on two types of populations of

women: women of reproductive age and women with a re-cent pregnancy. In studies targeting women of reproductiveage we calculated the prevalence of fistula per 1000 womenof reproductive age. In studies where women were followedafter end of pregnancy, we calculated the incidence of fis-tula per 1000 recently pregnant women (assuming thatwomen were unlikely to have had fistula before getting

pregnant). In all cases 95% confidence intervals were calcu-lated using the binomial exact method.Meta-analyses were conducted using the metaprop

command from the R 2.15.3 package meta using arandom-effects model [17]. Meta-analyses were conductedsummarising the prevalence of fistula among women ofreproductive age and the incidence of fistula in recentlypregnant women. All studies were stratified by continentand by recruitment in hospital or in the community.

ResultsThe initial search of studies focussing on fistula found9130 references after de-duplication, 367 of which wereretained after title and abstract screening. From the 367articles, six were found to have information on eitherprevalence or incidence of fistula [18-23]. A further 13
http://www.ohri.ca/programs/clinical_epidemiology/oxford.asphttp://www.ohri.ca/programs/clinical_epidemiology/oxford.asp

Table 1 Characteristics of studies reporting fistula prevalence included in the review

Author Study area Study design Assessment of fistula Number of fistula Number ofwomen/pregnancies

Prevalence(per 1000 WRA)

Community based studies

Muleta et al., 2008 [18] Seven rural administrativeregions in Ethiopia

Cross-sectional survey ofobstetric fistula

Women reporting leakage ofurine, faeces or both examinedin the health facilities

44 (untreated) 19,153 1.62 (1.53, 2.64)

Walraven et al., 2001 [24] Random sample of 20 ruralvillages in Farafenni, TheGambia

Census of all women aged 15-54for reproductive morbidity

External, vaginal speculum andbimanual pelvic examination byfemale gynaecologist

1 1,038 0.95 (0.02, 5.26)

Kulkarni, 2007 [35] Six PHC areas (urban andrural) in Maharashtra, India

Cross sectional survey ofnon-pregnant, ever married womenwith proven fertilityfor reproductive morbidity

Clinical examination butunspecified what or by whom

1 1,167 0.86 (0.02, 4.8)

Bhatia et al., 1997 [19] Villages (25% urban, 75% rural)with at least 500 people inKarnataka, India

Cross sectional study of all eligiblewomen under 35 with a childunder 5 for reproductive morbidity

External, vaginal speculum andbimanual pelvic examination byfemale gynaecologist

1 385 2.6 (0.07, 14.39)

Younis et al., 1993 [29] Two rural villages in Giza,Egypt

Cross sectional study ofreproductive morbidity inever-married, non pregnantwomen.

Speculum and bimanualexamination by femalephysicians [1]

0 509 0.0 (0.0 , 7.90)

Deeb et al., 2003 [27] Nabi Sheet, Lebanon Cross sectional study ofreproductive morbidity in evermarried, non-pregnant women

Thorough inspection of externalgenitalia, with speculumconducted by femalephysicians [1]

0 506 0.0 (0.0, 7.3)

Al-Riyami et al., 2007 [28] Oman, Mixed National Health Survey 2000 aimingto identify reproductive morbidity.Multi-stage stratified probability-sampling design of 1,968 householdswith ever married, non-pregnant women

Pelvic examination by a trainedphysician [1]

0 1,662 0.0 (0.0, 2.2)

Al-Qutob, 2001 [26] Ain Al-Basha, Jordan.Semi-urban

Random sample of Jordanianwomen

Comprehensive physical andpelvic examination conductedby trained female physician, anurse/midwife and a laboratorytechnician [1]

0 379 0.0 (0.0, 9.7)

Bulut et al., 1995 [25] City of Istanbul, Turkey Systematic sample of non-pregnant,ever married parous women whohad ever used contraception

Physical examination by femalephysician [1]

0 696 0.0 (0.0, 5.3)

Tehrani et al., 2011 [34] Four provinces of Iran Multi-stage stratified probability-sampling design of non-pregnantnon menopausal women 18-45

Comprehensive gynaecologicalexamination of all marriedwomen including a speculumexamination [1]

0 1117 0.0 (0.0. 3.3)

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Table 1 Characteristics of studies reporting fistula prevalence included in the review (Continued)

Studies with hospital based recruitment

Ijaiya and Aboyeji, 2004 [23] Ilorin, Nigeria, urban Hospital review of women with fistula repair Repair 34 32,188 1.1 (0.7, 1.5)

Kalilani-Phiri et al., 2010 [21] Nine districts (urban andrural) in Malawi

Hospital record reviews from gynaecological,prenatal, obstetric wards and operatingtheatres as well as fistula repair services.Only women originating from ninedistricts included

Repair 111 425,865 0.26 (0.2, 0.3)

Mabeya, 2004 [36] West Pokot, Kenya. Rural Hospital record review supplemented bysurgeons notes. Cases of fistulaepresenting to the two rural hospitals thatare the main hospitals in the district

Repair 66 150,000 0.44 (0.34, 0.55)

[1] These studies were reproductive morbidity studies which did not state in the methods that they were investigating fistula, nor did they report any cases of fistula; however the type of examination used to identifyother reproductive morbidities was assessed to have been sufficient that should there have been any cases of fistula they would have been identified.

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Table 2 Characteristics of studies reporting fistula incidence included in the review

Author Study area Study design Assessment of fistula Number offistula

Number of women/pregnancies

Incidence (per 1000pregnant women)

Community based studies

Vangeenderhuysen et al.,2001 [22]

Eight centres (urban andrural) in six countries inWest Africa

Prospective cohort study of allpregnant women found by adoor to door census of householdsfollowed up from antepartum totwo months postpartum.

Women reporting gynaecologicalproblems. Fistula assessed at lastcontact 60 days after delivery

2 19,694 0.10 (0.01, 0.3)

Ferdous et al., 2012 [33] Matlab, Bangladesh. Rural Prospective cohort of all womenwith obstetric complications, aperinatal death or caesareansection, and random sample ofwomen with uncomplicated births.

Physical examination at healthcentre from six to nine weekspostpartum

0 1,162 0 (0, 3.17)

Fronczak et al., 2005 [20] Urban slums in Dhaka,Bangladesh

Prospective community-based studyof women completing at least sevenmonths of pregnancy. Women excludedif birth identified more than 21 dayspostpartum. Sample selected usingmulti-stage probability.

Physical exam conducted byfemale physicians conductedone-month postpartum

0 557 0 (0.0. 6.6)

Studies with hospital based recruitment

Filippi et al., 2007 [30] Seven public urban and ruralhospitals in Burkina Faso

All women with severe obstetriccomplications delivering in hospitalsand two controls per case. Interviewsconducted at 3, 6, and 12 monthsafter pregnancy.

Medical examinations 1 1,014 0.99 (0.03, 5.48)

Filippi et al., 2010 [31] Cotonou, Porto Novo andneighbouring communitiesin south Benin

Prospective cohort study of womenwith severe obstetric complicationsand a sample of women withuncomplicated childbirth.

Medical examination withobstetricians

1 709 1.41 (0.04, 7.83)

Prual et al., 1998 [32] Niamey city, Niger. Urban All deliveries in six maternity wards,and all complications referred to thetwo referral maternity wards occurringfrom 28th week antenatal to 42nd daypostpartum.

Medical examinations 2 4,081 0.49 (0.06, 1.77)

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Figure 3 Prevalence of fistula per 1000 women of reproductive age.


studies [24-34] were found from searching general ma-ternal and reproductive morbidity studies (includingthree from reference lists and forward citation searching[34-36]) (Figure 2).Of the 19 studies, 13 were community-based; seven of

which reported on fistula [18-20,22,24,33,35] and sixdid not mention fistula anywhere in the paper. Tencommunity-based studies reported the prevalence of fis-tula among women of reproductive age (Table 1) andthree reported the incidence among recently pregnantwomen (Table 2). Six studies recruited women in hos-pital and followed them for 30 days or more after theend of pregnancy (Table 2). Three studies [21,23,36], re-port the prevalence of fistula among women after havingfistula repairs. These studies were included because itwas possible to understand the population that thesewomen came from, and have a denominator (Table 1).The other three studies reported the incidence of fistulaamong women after giving birth or miscarrying in hos-pital. These studies recruited women with obstetriccomplications as well as a sample of women withoutcomplications [30-32].

Figure 4 Prevalence of fistula per 1000 women of reproductive age s

Three community-based studies were from sub-SaharanAfrica [18,22,24], four were from South Asia [19,20,33,35],two were from North Africa [28,29], three from the Mid-dle East [26,27,34], and one from Turkey [25]. All sixstudies using hospital-based recruitment were from sub-Saharan Africa [21,23,30-32,36].The prevalence of fistula in community-based studies

ranged from 0 to 1.62 per 1000 women of reproductiveage with a median of 0 per 1000 (Figure 3). The pooledprevalence of fistula in community-based studies was0.29 (10 studies including 34,505 participants 95%CI 0.00, 1.07) per 1000 women of reproductive age(Figure 3). The pooled estimate for sub-Saharan Africaand South Asia was 1.13 (4 studies with 29,680 partici-pants 95% CI 0.72, 1.61) per 1000 women of reproduct-ive age (Figure 4). By continent Sub-Saharan Africa hadan overall prevalence of 1.60 (two studies including28,128 participants 95% CI 1.16, 2.10) per 1000 womenof reproductive age and South Asia had a prevalence of1.20 (two studies with 1552 participants 95% CI 0.10,3.63) per 1000 women of reproductive age (Figure 4).Because all studies from the Middle-East and North

tratified by region.

Figure 5 Prevalence of fistula per 1000 women of reproductive age in studies with hospital-based recruitment.


Africa had zero events, it is impossible for the meta-analysis to provide a meaningful estimate due to the man-ner with which zero prevalence studies are dealt with(http://cran.r-project.org/web/packages/meta/meta.pdf).The prevalence of fistula in studies with hospital-based

recruitment ranged from 0.26 to 1.06 per 1000 womenof reproductive age, with a median of 0.44 per 1000women of reproductive age. The pooled estimate of theprevalence of fistula in hospital was 0.51 (three studieswith 608,053 participants 95% CI 0.25, 0.87) per 1000women of reproductive age (Figure 5).The pooled incidence of fistula in community-based

studies was 0.09 (three studies with 21,413 participants0.01, 0.25) per 1000 recently pregnant women (Figure 6)and in hospital-based studies 0.66 (three studies includ-ing 5804 participants 0.16, 1.48) per 1000 recently preg-nant women (Figure 7).The I [2] values varied substantially by stratum, ranging

from 0% in community-based (Figure 6) and hospital-based (Figure 7) incidence studies to 94.8% in prevalencestudies with hospital based recruitment (Figure 5). Studyquality in the modified Ottawa-Newcastle score table isshown in Table 3. All studies had a cross-sectional or co-hort design.Only two studies reported information on duration of

fistula: one found a median of eight years [18], and the

Figure 6 Incidence of fistula per 1000 pregnancies in community-bas

other a median of three years [21]. No community basedstudies reported on the mode of delivery of the women,or on the cause of fistula.

DiscussionOur comprehensive systematic review found that fewerthan 1 per 1000 women of reproductive age in low andmiddle income countries suffer from fistula; this figurerises to 1.57 per 1000 when only data from sub-SaharanAfrica and South Asia is used. The number of new casesof fistula ranged from 0.09 per 1000 recently pregnantwomen in community-based studies to 0.66 per 1000pregnancies in hospital-based studies.The WHO has suggested that over two million women,

mostly from sub-Saharan African and Asian countries,have fistula [1,37]. Given an estimated population of 645million women of reproductive age in sub-Saharan Africaand South Asia in 2010 (http://esa.un.org/wpp/unpp/p2k0data.asp), this would suggest that 3 per 1000 womenof reproductive age have a fistula, which is considerablyhigher than our estimate for low and middle incomecountries. There were too few studies in our review to ar-rive at robust estimates of the prevalence of fistula by con-tinent, but even the highest estimates for sub-SaharanAfrica (1.62 per 1000 women of reproductive age inEthiopia) or South Asia (2.6 per 1000 in India) fall well

ed studies, stratified by region.
http://cran.r-project.org/web/packages/meta/meta.pdfhttp://esa.un.org/wpp/unpp/p2k0data.asphttp://esa.un.org/wpp/unpp/p2k0data.asp

Figure 7 Incidence of fistula per 1000 pregnant women in studies with hospital-based recruitment.


short of the WHO estimates. One study [22] estimated anincidence of 1.239 per 1000 deliveries in rural regions andused this to approximate 33,451 new fistula a year in SubSaharan Africa. This was based on 2 fistulae found in therural region in the MOMA study. Elsewhere they referto these regions as small towns [38]. They then used thesample of 2 fistulae per 1543 live births to estimate theoverall incidence for sub-Saharan Africa. This approach islikely to have over-estimated the number of fistulaepatients. First because a substantial proportion of Africanwomen now live in cities where the risk of fistulae islikely to be lower than in smaller towns or rural areas;second because the denominator does not include theurban women in larger cities for whom there were nofistulae occurrence.Overall, we estimate that just over one million women

may have a fistula in sub-Saharan Africa and South Asia,and that there are over 6000 new cases per year in thesetwo world regions. Given the devastating consequencesof fistula for women and their families, this represents avery substantial burden.It is possible that community based studies represent

an underestimate of the prevalence of fistula, as fistulaeare generally more commonly found in regions wherethere is no access to obstetric care, and may be difficultto reach. These women may have been missed in thestudies included here, and the estimates provided heremay represent a lower bound estimate of prevalence.However both the studies in Ethiopia [18] and theGambia [24] were conducted in rural areas, and bothstudies showed very low estimates of prevalence (1.62and 0.96 respectively).Our search identified 13 additional studies that would

not have been found had the search been restricted to fis-tula only. This was particularly relevant for community-based prevalence studies, where the specific fistula searchonly identified four studies, compared to nine when thesearch was expanded to maternal and reproductive mor-bidity studies. Inclusion of studies that did not mentionfistula could bias the results downwards since it is notcertain that women were examined for fistula. However,

our strategy of including only studies for which a thoroughgynaecological examination was conducted should haveensured that fistula would have been diagnosed and re-ported if present. Additionally, we only included studieswhich elicited uterine prolapse, since this implied athorough examination. Because fistula is a rare condi-tion, it is important to take account of studies that didnot find any fistulae, in the same way that studies withnegative findings are crucial in systematic reviews oftreatment effectiveness [39].We were unable to draw solid conclusions about re-

gional variations in the prevalence or incidence of fistula.We only found three community based studies fromsub-Saharan Africa and four community-based studiesfrom South Asia (all from India or Bangladesh). Manystudies were from very select communities and it isuncertain whether these findings are generalisable toAfrica and Asia as a whole. The heterogeneity in preva-lence or incidence of fistula in community-based stud-ies was very low however, suggesting that the prevalenceand incidence of fistula was uniformly low across allstudy sites.It is difficult to estimate the duration of fistula from

the reviewed studies because only two papers providedan estimate. However, given that one of these fromMalawi had a median duration of three years [21], andthe other from Ethiopia [18] had a median duration ofeight years, it seems that women can live with this con-dition for a very long time, in some contexts. Otherstudies have shown that women live with these condi-tions for years before presenting for fistula repair,sometimes as long as over 20 years [10]. Additionallythere was a lack of information on the mode of deliveryand cause of the fistula in the community based stud-ies, meaning that it is possible that some women suf-fered a fistula from causes other than prolonged orobstructed labour.The low prevalence and incidence of fistula among

women recruited in hospital is somewhat unexpected,since women seeking care from hospitals tend to be self-selecting because they are ill. The low incidence among

Table 3 Sources of risk of bias in included studies

Selection Comparability Outcome

Study: What is the casedefinition? (Conditionof interest)

Representativeness ofthe study population

Selection of non cases Comparabilityof cases andnon-cases

Assessmentof outcome

W study long enoughto nsure cases wouldbe ound

Differential follow up?

Muleta et al., 2008[18]

Obstetric fistula treatedand untreated

Population basedsample of sevenadministrativeregions of ruralEthiopia

Only women reportingleaking examined, thereforeit is possible that somewomen may have beencounted as non cases

All from samepopulation

Sufficient physicalexam

As ample was womenof productive age,so e women will haveon just given birthan it is possible theym have not yetde eloped fistula

Do not state

Walraven et al.,2001 [24]

Obstetric morbiditiesincluding fistula

Population basedrural region

All women invited for aphysical examination



As ample was womenof productive age,so e women will haveon just given birth andit possible they mayha not yet developedfis la

28% of sample did nothave examination

Kulkarni, 2007 [35] Obstetric morbiditiesincluding fistula

Population based Included all womenexamined



W en with children atle t six monthsex ined so assumptionis at it would be sixm ths postpartum

25% of sample womendid not have examination

Bhatia et al., 1997[19]

Gynecological morbidityincluding fistula




W en had exam afteron year so long enoughfo istula to develop

5% lost to follow up,6% not examined

Younis et al., 1993[29]

Gynaecological andrelated morbidities, butdo not state that theylooked for fistula


No cases Sufficient physicalexam

W en who were everm ried and notpr nant, so it ispo ible they may haveno yet developed fistula

Do not state

Deeb et al., 2003 [27] Gynaecological andrelated morbidities, butdo not state that theylooked for fistula



W en who were everm ried and not pregnant,so is possible they mayha not yet developedfis la

9% did not haveexamination

Al-Riyami et al., 2007[28]

Gynaecological andrelated morbidities, butdo not state that theylooked for fistula

Population basedfrom nationalsurvey

Included all womenexamined


As ample was women ofre oductive age, it ispo ible they may haveno yet developed fistula

Do not state

Al-Qutob, 2001 [26] Gynaecological andrelated morbidities, butdo not state that theylooked for fistula



W en who were everm ried and not pregnant,so is possible they mayha not yetde eloped fistula

10.7% did not haveexamination

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sremlydayv

sremlyisvetu

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Table 3 Sources of risk of bias in included studies (Continued)

Bulut et al., 1995 [25] Gynaecological andrelated morbidities,but do not statethat they lookedfor fistula

Population based, butin Istanbul which maynot be representativeof Turkey as a whole.Additionally onlyincluded women whohad ever usedcontraception



Unclear how long womenwere followed up forafter pregnancy


Tehrani et al., 2011[34]

Gynaecological andrelated morbidities,but do not statethat they looked forfistula



All women from 18-45who were not pregnant,so it is possible some maynot have had time forfistula to form

119 dropped out

Ijaiya and Aboyeji,2004 [23]

Obstetric fistula Hospital record reviewof fistula repairs withdetails about referencepopulation

Case series of repairs No non cases Physical examand treatment

All women already hadfistula. Possible thatwomen missed whodid not present fortreatment

N/A

Kalilani-Phiri et al.,2010 [21]

Obstetric fistula Hospital record reviewwith details ofpopulation it camefrom, howeverresearchers eliminatedall cases not originatingin the region.


All women already hadfistula. Possible thatwomen missed who didnot present for treatment

N/A

Mabeya, 2004 [36] Obstetric fistula Hospital record reviewof fistula repairs withdetails about referencepopulation


All women already hadfistula. Possible thatwomen missed who didnot present for treatment

N/A

Vangeenderhuysenet al., 2001 [22]





Followed up to 60 daysafter birth

5.7% loss to follow up

Ferdous et al., 2012[33]

All short and long termpostpartum morbiditiesincluding fistula

Women with morbiditiesand random sample ofall women




Examined 6-9 weekspostpartum

4.1% lost to follow upand 6.1% did not haveexamination

Fronczak et al., 2005[20]


Population based All women examined,but women who mayhave had fistula followedup longer



Women feared to havefistula followed up onemonth postpartum


Filippi et al., 2007[30]

Severe obstetriccomplicationsincluding fistula

Women withcomplications over-represented but alsohad follow up of womenwith uncomplicated birth

All women examined All from samepopulation


Women had follow upat six months

11% only had eitherinterview or physicalexam at six months

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Table 3 Sources of risk of bias in included studies (Continued)

Filippi et al., 2010[31]

Severe obstetriccomplicationsincluding fistula

Women withcomplications over-represented but alsohad follow up of womenwith uncomplicated birth



Women had follow upat six months

32% of women did nothave follow up at sixmonths

Prual et al., 1998 [32] Severe obstetriccomplicationsincluding fistula

Women with complicationsover-represented but alsohad follow up of womenwith uncomplicated birth



Unclear how long womenwere followed up for afterpregnancy so it is possiblethey may have not yetdeveloped fistula

Do not state

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women followed in the community after admission tohospital with near-miss obstetric morbidity (0.9 per 1000and 1.4 per 1000) [30,31] is particularly surprising, sincethis sample would have included a substantial number ofwomen with a prolonged and complicated labour. Forexample in Benin 27.1% of women had near-miss due todystocia, which would have included women with bothobstructed and prolonged labour [31]. Because thesewomen were recruited in hospital, a timely caesareansection may have prevented the fistula from developing.Reduced fertility is common in women with fistula (dueto loss of vagina, amenorrhoea, not engaging in inter-course, and inability to have a live baby) [2,7,9], and itis unlikely that women in the included incidence stud-ies would have had a fistula before getting pregnant.Attention should be drawn to the fact that the meta-analysis included one study from Ethiopia that had76.4% (Figure 3) or 91.3% of the weight in community-based studies (Figure 4), possibly inflating the pooledprevalence estimate.The low frequency of fistulae in any community make

survey enquiries that specifically target the countingof fistula cases prohibitively expensive given the largesample sizes required. Still, all community based studiesof reproductive health should explicitly ascertain and re-port the clinical presence or absence of fistula, evenwhen the sample size is small. .In many countries in sub-Saharan Africa there is an

emphasis on building specialised fistula hospitals dedi-cated to the treatment of women suffering from fistula.Given the rarity of the condition and the high level ofskills and training required for fistulae surgery, the resultsof this review suggest that the majority of the resourceswill always be better placed on prevention rather thancure. Strengthening maternal health services, creatingconditions for better transportation and communicationnetworks and training of local providers into the manage-ment of emergency complications, including with caesar-ean sections, would have the additional effect of providingcare for other causes of maternal and perinatal mortalityand morbidity.The relative rarity of fistula should not detract from

their public health importance. The estimated 6000 newcases of fistula per year in sub-Saharan Africa and SouthAsia are a painful testament to the continued failure ofhealth systems to manage labour complications effect-ively. Caesarean sections remain inaccessible to a largenumber of women in sub-Saharan Africa [40]. Delays inaccessing caesarean sections, faulty techniques and lackof caesarean sections all contribute to the burden of fis-tula. The fact that fistula have virtually disappeared in highincome countries suggest that they are entirely prevent-able. Given the seriousness of the condition, and the dev-astating consequences of fistula for women and their

families, efforts should also be made to find these womenand treat them.

ConclusionsOur study is the most comprehensive study of the bur-den of fistula to date, including study sources not gener-ally used. Our findings suggest that the prevalence andincidence of fistula is relatively low. The low burden offistula should not detract from their public health im-portance, however, given the preventability of the condi-tion, and the devastating consequences of fistula. Futurestudies of fistula should include a description of thestudy population with defined denominators.

Competing interestsThe authors declare that they have no competing interests.

Authors contributionsAJA conducted search, extracted data, did analysis and wrote first draft ofpaper CR advised on methodology and commented on drafts CCcommented on drafts and helped in writing of paper VF helped designstudy and commented on paper. All authors read and approved the finalmanuscript.

AcknowledgementsThe authors would like to thank Doris Chou, Lale Say, and Herbert Petersonfor their comments.

FundingThis research was funded through a grant made to the Child HealthEpidemiology Reference Group (CHERG) by the Bill and Melinda GatesFoundation.

Received: 13 June 2013 Accepted: 9 December 2013Published: 30 December 2013

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doi:10.1186/1471-2393-13-246Cite this article as: Adler et al.: Estimating the prevalence of obstetricfistula: a systematic review and meta-analysis. BMC Pregnancy andChildbirth 2013 13:246.

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http://www.who.int/healthinfo/statistics/bod_obstructedlabour.pdhttp://www.who.int/healthinfo/statistics/bod_obstructedlabour.pdhttp://www.icmrnicin/annual/2007-08/nirrh/chapter5pdfhttp://wwwgfmerch/Medical_education_En/PGC_RH_2004/Obstetric_fistula_Kenyahtmhttp://wwwgfmerch/Medical_education_En/PGC_RH_2004/Obstetric_fistula_Kenyahtmhttp://www.cochrane-handbook.orgAbstractBackgroundMethodsResultsConclusionsBackgroundMethodsResultsDiscussionConclusionsCompeting interestsAuthors contributionsFundingReferences
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