Associated Factors and Consequences of Uterine Fibroids in Hospitals in the Borgou Department of Benin in 2022 ()
1. Introduction
These are the most common benign gynecological tumors in women: A prevalence of 4.5% - 68.6% according to studies [1] . In France, Rongières et al. [2] reported a prevalence of 20% of patients aged 40 years or older with uterine fibroids and a preponderant incidence of 50% of women with uterine fibroids postmortem. Black American women are more likely to develop a uterine fibroid than white, Asian or Hispanic women: by menopause, 80% of black women had developed a uterine fibroid [3] . Their clinical manifestations are multiple, however the majority of them are asymptomatic [4] [5] . The discovery is often made during a consultation for the desire to have a child. The etiology of uterine fibroids remains unknown. They rarely appear before the first menstrual period and usually experience a regression after menopause. The consequences of uterine fibroids are often a threat to reproductive health. Outside of black race, certain risk factors for uterine fibroids have been described in the literature. However in Africa and in particular in Benin, few studies have looked at the epidemiology of uterine fibroids. The objective of our research was to determine the factors associated with uterine fibroids in the Borgou department of Benin in 2022.
2. Study Framework and Method
2.1. Type and Period of Study
This was an analytical, descriptive cross-sectional study with prospective data collection from August 22 to September 22, 2022.
2.2. Study Population
It consisted of women who came for gynecological consultation in the gynecology and obstetrics departments of the hospitals selected for this study, during the data collection period. The presence of uterine fibroids in a woman was confirmed by a pelvic ultrasound performed by a gynecologist or radiologist. Not included in this study were pregnant women. Our study excluded all women who did not give their free and informed consent.
The study took place in the Gynecology and Obstetrics Department 6 hospitals of the Borgou department in Benin in 2022: the Departmental University Hospital of Borgou and Alibori (DUH-B/A), the Army Training Hospital (ATH) of Parakou, the Saint Jean de Dieu Zone Hospital of Boko (SJZHB), the Saint Martin Zone Hospital of Papané (SMZHP), the Sounon Sero Zone Hospital of Nikki (SSZHN) and the Evangelical Zone Hospital of Bembèrèkè (EZHB).
2.3. Sampling
The sample size (N) was calculated according to the SCHWARTZ formula.
(1)
With: p: prevalence of fibroids worldwide (22.5%) [1] , q: 1 − p = 1 − 0.225 = 0.775, a first species risk (α) of 0.05 i.e. z α = 1.96; a desired accuracy (i) of 3%; N = (1.96)2 × 0.225 × 0.775/(0.03)2 = 744 subjects. The sampling technique is presented in three (03) steps:
· Step1: A cumulation of the expected populations of women of childbearing age (15 - 49 years) by health zone of the centers to be visited was made using the statistical numerical base of each health zone. Table 1 shows the expected population of women of childbearing age by health zone.
· Step 2: Calculation of the number of women to be surveyed per center: A weight (p) was calculated from the sample size and the cumulative found in step 1 and applied to the total number of women of childbearing age expected per health zone; this weighting allowed us to find the number of women to be surveyed per center to be surveyed. p = sample size/cumulative expected women of childbearing age = 744/557,801 = 0.00133381. This weight, multiplied by the total number of women of childbearing age expected per health zone, gives us the number of women to be surveyed per center. Table 1 shows the number of women of childbearing age to be surveyed by center.
· Step 3: In the health centers, the women to be surveyed were randomly selected until the height was reached
2.4. Data Collection
The collection technique was a structured interview with the administration of a digitized questionnaire to our respondents in the first instance and then secondarily the missing information was completed thanks to the consultation files after the interview. The data collection was done using a questionnaire that was validated, tested and digitized by the kobocollect application. A team had been set up and trained for this purpose. Also, the consultation boxes will be used for additional information.
2.5. Study Variable
The dependent variable was the presence of uterine fibroid.
The independent variables were:
· Sociodemographic variables: age, place of origin, occupation, level of education, marital status, household type, economic level
· anthropometric parameters: weight, height, body mass index (BMI)
· reasons for consultation
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Table 1. The socio-demographic characteristics of the study population.
· variables related to paraclinical examinations: pelvic ultrasound result, hemoglobin level
· Personal history: medical, gynecological, obstetric, surgical
· family history of uterine fibroids
2.6. Data Analysis
The data collected had been recorded and processed with Rstudio software. Qualitative variables were presented as percentages and quantitative variables were averaged with their standard deviations. Karl Pearson's uncorrected Chi-square (χ2) tests, Fisher’s exact tests were used to look for the statistically significant relationship. Measures of association had also been calculated. The significance level was set at a p-value of less than 0.05.
2.7. Ethical Considerations
The research protocol had been submitted to the local ethics committee of the University of Parakou for a favourable opinion. This work was carried out in accordance with the standards of professional conduct in force. The agreement of the authorities at various levels had been obtained. Patients’ verbal or written consent had been obtained.
3. Results
A total of 744 women across 6 sites were surveyed. The diagnosis of uterine fibroid was made in 10.1% of women seen in consultation with a 95% confidence interval of [8.1% - 12.4%].
3.1. Sociodemographic Characteristics of the Study Population
The mean age of women with uterine fibroids was 30.49 years ± 9.63 years with extremes of 13 and 70 years. 32.0% (24/75) of the women were housewives.
Women with uterine fibroids were married 54.7% (41/75), monogamous 50.7% (37/75), polygamous 49.3% (36/75), not in school 28.0% (21/75) and had a monthly income of less than 40000 Franc CFA (48/75). Table 2 presents the socio-demographic characteristics of the study population.
3.2. Method of Admission and Reasons for Consultation
All the women with uterine fibroids had gone to the various hospitals on their own. Desire for motherhood 50.7% (38/75), pelvic pain 46.7% (35/75) and genital hemorrhage 14.7% (11/75) were their main reasons for consultation. Genital hemorrhages were divided into menorrhagia 2.7% (2/75) and metrorrhagia 12% (9/75). Figure 1 shows the distribution of the study population by reason for consultation.
3.3. Background
Women with uterine fibroids were hypertensive (11/75) or 14.7%, diabetic (3/75) or 4.0%. 72.0% (54/75) of them had an irregular menstrual cycle, 37.3% (28/75) were on hormone treatment. They were paucigesture 32.0% (24/75) and nulliparous 37.3% (28/75). They had at least one miscarriage in 62.7% of cases. Table 3
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Table 2. Socio-demographic characteristics of the study population.
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Figure 1. Distribution of women consulting gynecology according to the reason for consultation.
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Table 3. Distribution of the study population according to their reproductive characteristics.
shows the distribution of the study population by reproductive characteristics.
One of the women with uterine fibroids had a family history of uterine fibroids, which is 1.3% of cases.
3.4. Classification of Uterine Fibroids
The mean height of the uterus in patients with fibroids was 3.69 cm with extremes of 0 and 31 cm. 56.0% (42/75) of uterine fibroids were multiple, and 44.0% (33/75) of them were single. Of the 75 women with uterine fibroids, 19 women were classified as stage 2 according to the FIGO classification of uterine fibroids, i.e. 25.3%. Fibroids were submucosal 57.3% (43/75), interstitial 48.0% (36/75), and subserosal 22.7% (17/75). Table 4 shows the distribution of uterine fibroid cases according to the FIGO classification. A proportion of 28% (21/75) of women with uterine fibroids had an associated ovarian cyst.
3.5. Complications of Uterine Fibroids
A proportion 80.0% (60/75) of women with uterine fibroids had at least one complication. In fact, we recorded 54.7% (41/75) of uterine fibroids complicated by infertility. Table 5 shows the distribution of women with uterine fibroids according to their complications.
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Table 4. Distribution of uterine fibroids according to the International Federation of Obstetrics and Gynecology (FIGO) classification.
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Table 5. Distribution of women with uterine fibroids according to their complications.
3.6. Analytique Study
Table 6 provides a comprehensive analysis of the factors associated with and consequences of uterine fibroids in hospitals within the Borgou department in Benin in 2022. Upon examining the data, several significant trends emerge,
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Table 6. Factors Associated with uterine fibroids.
highlighting associations. Concerning age, a statistically significant correlation has been established (p < 0.0001). The analysis reveals a substantial increase in the relative risk (RR) with age, indicating a rising prevalence of uterine fibroids among older women. Regarding Body Mass Index (BMI), although the trend suggests a slightly higher risk in women with BMI ≥ 30, no significant association was observed (p = 0.0785). Parity did not show a significant link to the presence of uterine fibroids (p = 0.6631), indicating that different parity levels do not exhibit marked variations in fibroid prevalence. The number of miscarriages demonstrates a significant correlation with uterine fibroids (p < 0.0001). Women who had 1 to 2 miscarriages have an increased risk, and this risk substantially rises for those who had 3 to 7 miscarriages. A significant association was evident between a history of hypertension and the presence of uterine fibroids (p < 0.0001). Women with a history of hypertension had a high risk of developing fibroids compared to those without such history. As for the history of diabetes, a significant association is also observed (p = 0.0004), indicating an increased risk of uterine fibroids among women with a history of diabetes.
3.7. Profile of Women with Uterine Fibroids
In this study, women with uterine fibroids were aged 30 to 39 years, housewives, married, paucigesture and nulliparous, with a history of spontaneous miscarriage.
4. Discussion
This was a cross-sectional study with an analytical purpose and prospective data collection. The sampling technique used allowed us to determine the number of women to be surveyed per center. Random sampling helps to limit sampling bias. There are certainly some biases in this study that are specific to studies based on declarative data and those specific to the choice of collection sites that are hospitals. Our results were based on hospital data. These results could be generalized to women seen in gynaecological consultations in northern Benin. But they could not be generalized to the population of northern Benin.
At the end of this work, our objectives had been achieved: The frequency of uterine fibroids in hospitals in northern Benin was 10.1% (75/745) among female gynecological consultants, with a 95% confidence interval of [8.1% - 12.4%]. Factors associated with uterine fibroids were: age (p < 0.0001), history of miscarriage (p < 0.0001),, history of high blood pressure (p < 0.0001), and history of diabetes (p = 0.0004). The consequences of uterine fibroids were: infertility (54.7%), pelvic pain (12.0%), menometrorrhagia (9.3%), anemia (6.7%), aseptic necrobiosis (1.3%).
The frequency of symptomatic uterine fibroids was 10.1% in hospitals in northern Benin. This frequency is similar to those reported in population-based studies by Fernandez et al. [6] in France (8.8%), Zimmermann et al. [7] in Italy (9.8%), Korea (9%), Germany (8%) and Brazil (7%). These results confirm that most uterine fibroids are asymptomatic.
In our series, the main reasons for consultation for women with uterine fibroids were: desire for motherhood (50.7%), pelvic pain (46.7%) and genital hemorrhage (14.7%). Dembele et al. [8] find in their series the same reasons for consultation but in different proportions: desire for motherhood (35%), pelvic pain (35%), genital hemorrhage (17.5%). These observed differences could be explained by the difference in the study methods used.
In this study, half of the women (50.7%) with uterine fibroids had consulted for desire for motherhood. Dembele et al. [8] in Kayes, also report a high proportion of women with uterine fibroids seen in consultation for desire for motherhood (35%). These high proportions could be explained by the culture in Africa characterized by the importance of motherhood for women. Uterine fibroids accounted for 2-3% of causes of infertility [9] [10] . Interstitial and submucosal uterine fibroids are characterized by low fertility and a higher rate of spontaneous miscarriage [5] [9] .
Menorrhagia accounted for 12.0% of the reasons for consultation among women with uterine fibroids. This frequency is similar to that reported by Tiemtoré-Kambou et al. [11] in Burkina Faso (12.1%).
In this study, we found 57.3% submucosal fibroid, 48% interstitial fibroid, 22.7% sub-serosal fibroid. These results are different depending of the study population and methodology: Balungwe et al. [12] in the Democratic Republic of Congo had found 48.6% submucosal fibroid, 0.55% interstitial fibroid, 1% subserosal fibroid. Tiemtoré-Kambou et al. [11] in Burkina Faso had found 6.4% submucosal fibroid, 48.9% interstitial fibroid, 11.8% subserosal fibroid.
Statistical age was linked to the appearance of uterine fibroids (P < 0.0001). Indeed. Compared to women aged 20 to 29, women aged 30 and over have a greater risk of having a uterine fibroid (RP = 2.1). 95% CI [1.12 - 3.92] with a higher risk between 40 and 49 years (RP = 7.54). 95% CI [3.87 - 14.70]. According to Wise et al. [13] the highest incidence of uterine fibroids is in the 40 - 44 age group. According to the study by Baird et al. [14] in the United States, 60% of women have a uterine fibroid at menopause (age 50). The appearance of uterine fibroids is similar to the period of genital activity. Their development occurs in the post-pubertal period and their growth decreases from menopause. The rate of appearance increases with age to reach acne in the perimenopausal period [2] .
History of high blood pressure was statistically associated with uterine fibroid (p < 0.0001). A similar result was reported by Boynton-Jarrett et al. [15] . According to these authors’ explanations, high blood pressure represents a “proatherogenic” state which increases the risk of developing uterine fibroids. Elevated blood pressure can cause damage to smooth muscle cells and/or release of cytokines and thus increase the risk of the appearance or growth of uterine fibroids in a process analogous to atherosclerosis [15] .
We also found that diabetes was statistically associated with uterine fibroid (p = 0.0004) but there was no association between body mass index and uterine fibroid. According to some studies, obesity and excessive weight gain had a positive association with fibroids [6] [16] .
Spontaneous miscarriages were significantly associated with the presence of uterine fibroids (p < 0.0001). The greater the number of miscarriages, the greater the risk of having a fibroid. Klatsky et al. [17] finds an association between interstitial fibroids and spontaneous miscarriages. Kellal et al. [18] found a significant association between first trimester bleeding and uterine fibroids during pregnancy. These first trimester bleedings and spontaneous miscarriages in cases of fibroid and pregnancy association could be explained by the hormonal imbalance common during fibromatous disease on the one hand, and on the other hand by the deformation of the uterine cavity due to the presence of submucosal fibroid [18] .
5. Conclusion
Uterine fibroids are common in hospitals in northern Benin. Their main circumstance of discovery was the desire for motherhood. We found certain factors that were associated with these uterine fibroids. These factors should be taken into account in management strategies for this condition.
Annexe—Questionnaire
Departmental University Hospital of Borgou and Alibori (DUH-B/A); Saint Martin Zone Hospital of Papanè (SMZHP); Evangelical Zone Hospital of Bembèrèkè (EZHB); Saint Jean de Dieu Zone Hospital of Boko (SJZHB); Sounon Sero Zone Hospital of Nikki (SSZHN); Army Training Hospital (ATH) of Parakou.