Introduction

Definition and pathophysiology

Obstetric fistula is the presence of a hole between a woman’s genital tract and urinary tract (i.e., vesicovaginal fistula) or between the genital tract and the intestines (i.e., rectovaginal fistula). The vesicovaginal fistula is characterized by the leakage of the urine through the vagina, and rectovaginal fistula is characterized by the leakage of flatus and stool through the vagina. Both vesicovaginal and rectovaginal fistula are associated with a persistent offensive odor leading to the social stigma and ostracization of these affected women [1, 2]. There are three prominent causes of obstetric fistula. The cause of obstetric fistula is ischemia of the soft tissue between the vagina and the urinary tract or between the vagina and the rectum by compression of the fetal head. The second most common cause of obstetric fistula is the direct tearing of the same soft tissue during precipitous delivery or obstetric maneuvers. The last and least common cause is elective abortion [3, 4]. These causes are not mutually exclusive and may have additive effects. Each of these causes occurs as a complication of delivery or uterine evacuation usually in the absence of skilled medical staff assistance.

Incidence and prevalence

Obstetric fistula is found in all developing countries including South Africa. However, the majority of obstetric fistulae are confined to the “fistula belt” across the northern half of sub-Saharan Africa from Mauritania to Eritrea and in the developing countries of the Middle East Asia.

Several population-based estimates of obstetric fistula have been presented in the obstetrical literature. The most frequently cited estimate is the one introduced by Waaldijk in 1993 when he cited an incidence rate of 1 to 2 per 1,000 deliveries. This incidence rate suggested a worldwide incidence of 50,000 to 100,000 new cases annually; and a worldwide prevalence of 2 million cases of obstetric fistulae [5]. A recent study highlighted the lack of a scientific basis for this incidence and prevalence of fistulae [6]. These authors reported an estimated prevalence of 188 per 100,000 women aged 15 to 49 years in South Saharan Africa and emphasized the need for population-based studies.

Risk factors

Seven primary risk factors for obstetrical fistula commonly reported include the place of birth and presence of a skilled birth attendant, the duration of labor and the use of a partograph, the lack of prenatal care, early marriage and young age at delivery, older age, lack of family planning, and a number of other poorly defined additional factors[3, 4]. Obstetrical fistula is most often the result of prolonged and obstructed labor. Up to 95.5% of 259 cases of obstetrical fistulae reported in Zambia occurred following labor for more than 24 h before the completion of delivery [7]. Ninety-two percent of 201 fistula cases reported in northern Ethiopian women did not have any antenatal care [8]. Eighty-five percent of the 52 fistula patients in a Niger series delivered at home [9].

These underlying characteristics were not found in other low prevalence series [7, 10]. Only 20.0% of 52 cases of fistula reported in Saudia Arabia had a duration of labor lasting for more than 24 h [10]. In Zambia, only 2.5% of 259 patients reported no antenatal care before delivery [7]. Delivery at home was reported by only 9.6% of the 259 patients in the same report [7].

The data on risk factors for obstetrical fistula are controversial. Better knowledge of the risk factors for obstetrical fistula is needed to educate the community, healthcare providers, policy makers, and program managers to improve prevention of obstetric fistula at a regional and national level.

Objectives

The purpose of this study is to assess the current state of knowledge regarding the characteristics of obstetric fistula patients. To do so, we compile the international literature on obstetric fistula to identify the relevant information on the demographic, socioeconomic status of the patients, and circumstance of occurrence of the disease.

Methods

Data sources

We conducted a search of the literature to identify all relevant articles published during the period of 1987–2008 in the Medline (PubMed, Ovid), Cochrane Trials Register, and Cumulative Index to Nursing and Allied Health databases. We conducted a variety of searches using a combination of the following medical terms and MeSH headings: obstetric fistula, urinary fistula, vesicovaginal fistula, vesico vaginal fistula, vesico-vaginal fistula, recto-vaginal fistula, rectovaginal fistula, and recto vaginal fistula. In addition, potentially relevant publications were identified from the reference lists of identified articles and from review articles. No attempt was made to identify unpublished studies.

Study selection

Descriptive or analytic studies presenting the characteristics or the outcome of women suffering from genital fistula were initially eligible for inclusion. Data regarding the place of birth, presence of a skilled birth attendant, the duration of labor, mode of delivery, the presence of antenatal care, the age at marriage, the age at first delivery, age at causal delivery, parity at causal delivery, use of family planning, and other additional factors were reviewed. After identification of potentially relevant studies, each of these studies was reviewed in detail, and additional exclusion criteria were applied.

Studies providing complete or partial information on the sociodemographic characteristics of obstetrical fistula patients, access to health care or its consequences were included. Studies were excluded if they reported only the outcome without any presenting sociodemographic characteristics or information about access to emergency health care. Studies were excluded from this analysis if they did not include information on the central tendency or the age of the affected women, proportion of obstetrical causes of fistula, or information about the site(s) of fistulae. Articles were also excluded if they included fewer than 20 cases or if they only reported on selected cases.

Data extraction and analysis

From these articles we extracted the following variables for the review: country of the study, study design, age of the patients, place of causal birth, skilled birth attendance; the duration of labor, mode of delivery, the presence of antenatal care; age at marriage, age at causative delivery, parity at the occurrence of the fistula, and a number of little defined additional factors.

Results

We found 28 studies that presented some information about the characteristics and outcomes of fistula patients. Four studies were excluded because they reported only 1 to 20 cases [11–14]. Three studies were excluded because it was not possible to determine which fistula cases were obstetrical [15–17].Two studies were excluded because of the selective status of the included cases [18, 19]. Nineteen studies were chosen for analysis in this review. Tables 1 and 2 show the characteristics of the studies selected [4, 7–10, 20–33]. Among the 19 selected studies, 15 were from sub-Saharan Africa and 4 were from the Middle East (Table 1). Seventeen studies were retrospective case series, and two were surveys (Table 1, 2). Among the selected studies, there were two reports of only rectovaginal fistulae (RVpur); three studies reported only cases of vesicovaginal fistulae (VVpur); nine studies reported on subjects with both vesicovaginal and associated rectovaginal fistulae in the same patient (VVc), and five reports included pure vesicovaginal cases, pure rectovaginal cases, and associated cases(V/R; Table 1). Among the fistula cases, 79.4% to 100% were obstetrical while the remaining cases were from other causes (Table 2). Rectovaginal fistula represented 1% to 8% of cases; vesicovaginal fistula made up 79% to 100% of cases, and combined vesico and rectovaginal fistula represented 1% to 23% of cases (Table 2). Illiteracy among the obstetrical fistula patients ranged from 19% to 96% (Table 3).

Table 1 Classification of the selected studies. Studies selected for analysis of obstetrical fistula patients characteristics (Part 1)
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Table 2 Organ related classification of obstetrical fistula included in selected studies
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Table 3 Risk factors of obstetrical fistula and illiteracy status of the patients (Part 2)
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At the time of management, 8.9% to 86% of patients were teenagers (Table 4). Thirty-one to 66.7% of patients were primiparous at the time of the incident delivery resulting in fistula (Table 5).

Table 4 Teenage status of the patients
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Table 5 Parity of the patients
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Among the obstetric fistula patients, 57.6% to 94.8% of women tried to deliver at home and were secondarily transferred to the health facility. However, 9% to 84% of the patients delivered at home (Table 6). Many obstetrical fistula patients (40–79.4%) were less than 150 cm tall (Table 7).

Table 6 Antenatal care and place of delivery
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Table 7 Height of the patients
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The mean duration of labor among the fistula patients ranged from 2.5 to 4 days. Twenty to 95.7% of patients labored for more than 24 h. Operative delivery was performed in 11% to 60% of fistula cases (Table 8). The indexed delivery resulted in stillbirth for 78% to 96% of patients [7, 8, 22, 26, 28, 29, 32] (Table 9).

Table 8 Duration of labor and mode of delivery
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Table 9 Stillbirth status of the patients
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Discussion

We found that 8.9% to 86% of obstetrical fistula patients are teenagers at the time of management (Table 4), and 31% to 66.7% were primiparous at the moment of occurrence. (Table 5). Previous studies found a higher rate of obstetrical complications in teenagers; Unfer et al. reported a higher rate of cesarean section in teenagers compared to women in their twenties. Unfer et al. also reported a higher incidence of low birth weight infants and acute intrapartum distress in adolescent mothers [34]. The increased obstetrical risk in teenagers can partially be explained by anatomic immaturity. Teenage pregnancies account for a higher proportion of all pregnancies (7–30%) in developing countries [35, 36]. These findings suggest that efforts to reduce obstetrical fistula should target teenagers.

We found that 57.6% to 94.8% of obstetrical fistula patients tried to labor at home but were later transferred to health facilities and 9% to 84% of the patients delivered at home (Table 6).

The WHO recommends that labor should be monitored with a partograph (an instrument on which the labor events are recorded) and interpreted for decision making during labor and delivery. This is impossible if women choose to labor at home [37, 38]. When women try to labor at home unsuccessfully, they are more likely to come to the hospital at a late stage. This may be further delayed by the absence of transportation, poor roads, heavy rains, and great distances to the health facility. In many developing countries, patients have to use their own money to pay for health care, and this may further delay treatment.

The mean duration of labor in fistula patients ranged from 2.5 to 4 days. Twenty to 95.7% of these women had labored for more than 24 h, and operative delivery was performed in 11% to 60% of the indexed deliveries leading to fistula formation (Table 8). Cephalopelvic disproportion (CPD) was the most common indication for cesarean delivery in sub-Saharan Africa [39–41]. Previous studies have found CPD as the primary indication in 30%, 33%, and 34% of cesarean deliveries in Senegal, Cameroon, and Namibia, respectively.

Delay in intervention increases the time of compression of the mother’s soft pelvic organs (i.e., bladder and rectum) between the fetal presentating part (i.e., the fetal head) and the mother’s pelvic bones, leading to uterine rupture, obstetric fistula, and fetal death. These observations suggest that emergency obstetrical care should be a cornerstone of any obstetrical fistula prevention program. We found that more than 78% of fistula patients did not have a live baby. Our findings strongly emphasize on the association between obstetric fistula (OF) and stillbirth. This suggests that the OF patients will not suffer only from their physical condition but will also suffer from psychological setbacks due to the loss of the pregnancy [7, 8, 22, 26, 28, 29, 32].

Conclusion

Obstetric fistula is associated with several risk factors, and they appear to be preventable. This disease is associated with teenage status at delivery, primiparity, prolonged labor, home delivery, and short status at delivery. Knowledge of the leading risk factors for obstetrical fistula in a given population is of paramount importance and should be studied. This knowledge should be used in strengthening preventive strategies both at the health facility and at the community level.