Prevalence and Correlates of Pelvic Endometriosis in an Urban Center of Cameroon: A Cross-Sectional Study

Background: Endometriosis is a common gynecological condition worldwide but remains poorly documented in sub-Saharan Africa, largely due to limited access to diagnostic laparoscopy. Understanding its prevalence and associated factors is essential for imp roving clinical recognition and management. Ob- jective: To determine the surgical prevalence and factors associated with pel- vic endometriosis among women undergoing gynecological laparoscopy in Douala, Cameroon. Methods: We conducted a retrospective cross -sectional study over a 10 -year period (January 2014 -December 2022) in three tertiary hospitals in Douala. Medical records of women who underwent gynecological laparoscopy for indications such as infertility, chronic pelvic pain, adnexal masses, or suspected ectopic pregnancy were reviewed. Pelvic endometrio sis was primarily diagnosed by direct laparoscopic visualization of characteristic lesions by experienced surgeons. Biopsy with histological confirmation was performed when lesions were atypical or when diagnostic uncertainty existed. Data were analyzed using SPSS version 24.0. Bivariate and multivariate logistic regression analyses were performed to identify factors associated with pelvic endometriosis. Adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were calculated, and statistical significan ce was set at p < 0.05. Results: How to cite this paper: Nana, T.N., Tongna, A.E.N., Tchounzou, R., Nkwele, F.M., Neng, H., Njamen, C.J.N., Mbi, F.K., Ndzometia, C., Eyong, I.M., Wambo, A.G.S., Ngalame, A., Nguefack, C.T., Ekane, G.H., Egbe, T.O., Essome, H. and Mboudou, E. (2026) Prevalence and Corre- lates of Pelvic Endometriosis in an Urban Center of Cameroon: A Cross-Sectional Study. Open Journal of Obstetrics and Gy- necology, 16, 687-699. https://doi.org/10.4236/ojog.2026.165067 Received: March 5, 2026 Accepted: May 6, 2026 Published: May 9, 2026 Copyright © 2026 by author(s) and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access T. N. Nana et al. DOI: 10.4236/ojog.2026.165067 688 Open Journal of Obstetrics and Gynecology A total of 440 women were included. The surgical prevalence of laparoscopi- cally diagnosed pelvic endometriosis was 22.5%. Histological confirmation was obtained in 81 of the 88 biopsied cases (92.0%). In multivariate analysis, age at menarche ≤ 11 years (A OR = 5.14; 95% CI: 2.49 - 10.64; p < 0.001) and menstrual cycle length ≤ 27 days (AOR = 5.20; 95% CI: 2.91 - 9.30; p < 0.001) were independently associated with increased odds of endometriosis. Con- versely, a history of pelvic surgery (AOR = 0.30; 95% CI: 0.14 - 0.61; p < 0.001), primigravidity (AOR = 0.49; 95% CI: 0.25 - 0.98; p = 0.045), and paucigravidity (AOR = 0.34; 95% CI: 0.16 - 0.70; p = 0.003) were inversely associated with endometriosis. Conclusion: Nearly one-quarter of women undergoing gyne- cological laparoscopy in three tertiary hospitals in Douala had pelvic endome- triosis. Early menarche and short menstrual cycles were strongly associated with the condition, while prior pelvic surgery and low grav idity showed in- verse associations. These findings highlight the impo rtance of improving ac- cess to laparoscopic diagnostic services to enhance the detection and manage- ment of endometriosis in similar resource-limited settings.

Pelvic Endometriosis, Prevalence, Associated Factors, Laparoscopy, Cameroon, Sub-Saharan Africa 1. Introduction Endometriosis is a chronic gynecological condition characterized by the presence of endometrial glands and/or stroma outside the uterine cavity, commonly involv- ing the ovaries, fallopian tubes, and pelvic peritoneum, with possible extra-pelvic manifestations [1]-[3]. Its clinical presentation is heterogeneous, ranging from se- vere symptoms to asymptomatic disease, which often leads to delayed diagnosis. Globally, endometriosis affects approximately 10% of women of reproductive age, representing nearly 190 million individuals worldwide and constituting a ma- jor public health concern [4]. The true burden of disease is likely underestimated due to nonspecific symptoms, such as chronic pelvic pain and infertility, and lim- ited access to diagnostic laparoscopy in many settings [5]-[7]. In sub-Saharan Africa, reported prevalence rates are relatively low, largely re- flecting underdiagnosis and restricted availability of minimally invasive surgical techniques [8]. However, hospital-based studies in Cameroon have documented prevalence rates between 13.5% and 22.5% among women undergoing surgery for infertility or chronic pelvic pain, suggesting a substantial but under recognized disease burden [9] [10]. Several reproductive, menstrual, and surgical factors have been associated with endometriosis, although reported risk profiles vary across studies due to differ- ences in populations, diagnostic methods, and study designs [11]-[13]. In resource- limited settings, identifying context-specific associated factors is essential to im- prove clinical suspicion and guide appropriate referral for surgical diagnosis. T. N. Nana et al. DOI: 10.4236/ojog.2026.165067 689 Open Journal of Obstetrics and Gynecology In Cameroon, data on endometriosis remain scarce, and limited access to lapa- roscopy contributes to delayed diagnosis, with significant consequences for fertil- ity, quality of life, and psychological well-being [14]. As the surgical prevalence and associated factors of endometriosis in urban Cameroonian settings remain insuf- ficiently characterized, this study aimed to determine the prevalence and identify factors associated with pelvic endometriosis among women undergoing laparo- scopic surgery in three hospitals in Douala, Cameroon. 2. Materials and Methods 2.1. Study Design and Period We conducted a hospital-based cross-sectional analytical study with retrospective data collection. Medical records covering a 10-year period from January 1, 2014 to December 31, 2022 were reviewed. Data collection and analysis were conducted over a five-month period from January to June 2025. 2.2. Study Setting The study was conducted in the gynecology departments of three specialized healthcare facilities in Douala, Cameroon:  Douala General Hospital (HGD)  Douala Gyneco-Obstetrics and Pediatrics Hospital (DGOPH)  Clinique de l’Aéroport (CA) The first two institutions are tertiary-level teaching and referral hospitals providing advanced gynecological care and specialist training. Clinique de l’Aéro- port is a private healthcare facility specialized in minimally invasive gynecological surgery and assisted reproductive techniques. All three centers are equipped with video-laparoscopy systems enabling direct visualization of pelvic structures. Laparoscopic procedures were performed by ex- perienced gynecologic surgeons with 8 - 35 years of surgical experience. 2.3. Study Population and Eligibility Criteria A non-probabilistic exhaustive sampling method was used. We included all medical records of women who underwent diagnostic and/or operative gynecological laparoscopy during the study period for indications in- cluding infertility, chronic pelvic pain, adnexal masses, or suspected ectopic preg- nancy. A diagnosis of pelvic endometriosis was retained when one of the following cri- teria was met: 1) Laparoscopic diagnosis: Direct visualization of typical endometriotic lesions such as powder-burn lesions, ovarian endometriomas, or deep infiltrating nodules by experienced surgeons. 2) Histological confirmation: Identification of endometrial glands and/or stroma on histopathological examination of biopsy specimens obtained during laparoscopy. T. N. Nana et al. DOI: 10.4236/ojog.2026.165067 690 Open Journal of Obstetrics and Gynecology Diagnosis was primarily based on laparoscopic visualization. Biopsy with his- tological examination was performed when lesions appeared atypical or when di- agnostic uncertainty existed. Medical records with incomplete data (defined as missing more than 20% of required study variables) were excluded from the analysis. 2.4. Data Collection and Study Variables Following administrative authorization and ethical approval, surgical registers were reviewed to identify eligible cases. Complete medical files were subsequently retrieved from hospital archives. Data were collected using a standardized data ex- traction form developed in accordance with the study objectives and relevant lit- erature. The form was pretested on a subset of medical records not included in the final analysis and refined accordingly. Data extraction was carried out by trained physicians under the supervision of the principal investigator. To ensure data qual- ity and consistency, a random sample of records was cross-checked, and any dis- crepancies were resolved through consensus. Sociodemographic characteristics: Age, marital status, education level, and oc- cupation. Gynaecological and reproductive variables: Age at menarche, menstrual cycle length and regularity, gravidity, parity, and family history of endometriosis. Medical and surgical history: History of diabetes mellitus, hypertension, prior abdominal or pelvic surgery. Lifestyle factors: Alcohol consumption and tobacco use. All laparoscopic procedures were performed by senior surgeons with docu- mented expertise in minimally invasive gynaecological surgery. 2.5. Sampling Method and Sample Size An exhaustive sampling approach was adopted, including all eligible cases that met the inclusion criteria during the study period. As a result, no a priori sample size calculation was performed. The final sample size corresponded to the total number of complete medical records available and eligible across the three study sites. 2.6. Data Management and Statistical Analysis Data were entered and analyzed using SPSS version 24.0. Categorical variables were summarized as frequencies and percentages. Bivariate analysis was performed to evaluate associations between pelvic endo- metriosis and independent variables using crude odds ratios (ORs) with their 95% confidence intervals (CIs). Variables with p < 0.20 in bivariate analysis were included in a multivariate lo- gistic regression model to identify independent factors associated with endome- triosis while controlling for potential confounders. Adjusted odds ratios (AORs) with 95% confidence intervals were reported. Sta- tistical significance was set at p < 0.05. T. N. Nana et al. DOI: 10.4236/ojog.2026.165067 691 Open Journal of Obstetrics and Gynecology Family history of endometriosis was not included in the multivariate model due to complete separation, as no cases were observed among the control group, pre- venting reliable estimation of adjusted odds ratios. 2.7. Ethical Considerations The study was conducted in accordance with the ethical principles of biomedical research involving human subjects. Ethical approval was obtained from the Insti- tutional Ethics and Research Committee (2025/083/UDM/PR/CEAQ ). Given the retrospective nature of the study, informed consent was waived. Patient confiden- tiality was strictly maintained by anonymizing all extracted data and restricting access to study files to the researchers. 3. Results 3.1. Study Population and Surgical Prevalence of Pelvic Endometriosis During the study period, 506 women underwent gynecological laparoscopy in the three participating centres. Of these, 440 patients (87.0%) met the inclusion crite- ria and were included in the analysis. Pelvic endometriosis was identified in 99 women, yielding a surgical prevalence of 22.5% among women undergoing laparoscopy. Diagnosis was based on direct laparoscopic visualization of typical endometri- otic lesions (Figures 1 -3). Biopsies for histological confirmation were performed in 88 cases (20.0%), with histopathology confirming endometriosis in 81 cases, corresponding to a confirmation rate of 92.0%. Figure 1. Bilateral endometrioma. Figure 2. Laceration of the pelvic parietal peritoneum. Clear, reddish, and brownish endo- metriotic vesicles. T. N. Nana et al. DOI: 10.4236/ojog.2026.165067 692 Open Journal of Obstetrics and Gynecology Figure 3. Brownish hemoperitoneum; clear endometriotic vesicles. On a hypervascularized parietal peritoneum. 3.2. Bivariate Analysis of Socio-Demographic Factors In bivariate analysis, occupation in the private sector was significantly associated with pelvic endometriosis. Women working in the private sector had more than twice the odds of endometriosis compared with those in the informal sector (OR = 2.47; 95% CI: 1.20 - 5.09; p = 0.014). Age, marital status, and level of education were not significantly associated with pelvic endometriosis in bivariate analysis (Table 1 ). Table 1 . Socio-demographic factors associated with pelvic endometriosis (Bivariate analy- sis). Variables Endometriosis Present (N = 99) n (%) Endometriosis Absent (N = 341) n (%) Odds Ratio (OR) (95% CI) p-Value Age (years) 15 - 24 9 (9.1) 28 (8.2) 4.18 (0.48 - 36.53) 0.196 25 - 34 59 (59.6) 170 (49.9) 4.51 (0.58 - 35.24) 0.151 35 - 44 30 (30.3) 130 (38.1) 3.00 (0.38 - 23.83) 0.299 45 - 54 1 (1.0) 13 (3.8) 1 (reference) Marital status Single 33 (33.3) 146 (42.8) 1 (reference) Married 63 (63.6) 190 (55.7) 1.47 (0.91 - 2.35) 0.112 Widow/divorced 3 (3.0) 5 (1.5) 2.65 (0.60 - 11.67) 0.196 Occupation Private 22 (22.2) 43 (12.6) 2.47 (1.20 - 5.09) 0.014 Public 36 (36.4) 134 (39.3) 1.30 (0.69 - 2.43) 0.415 Informal 18 (18.2) 87 (25.5) 1 (reference) None 23 (23.2) 77 (22.6) 1.44 (0.72 - 2.87) 0.296 T. N. Nana et al. DOI: 10.4236/ojog.2026.165067 693 Open Journal of Obstetrics and Gynecology Continued Level of education Primary 3 (3.0) 19 (5.6) 1 (reference) Secondary 26 (26.3) 129 (37.8) 1.28 (0.35 - 4.63) 0.710 Higher 70 (70.7) 193 (56.6) 2.30 (0.66 - 8.00) 0.191 Notes: 1) The reference group for Age is 45 - 54 years, 2) The reference group for Marital status is Single, 3) The reference group for Occupation is Informal, 4) The reference group for Level of education is Primary , 5) Significant result at p < 0.05: Occupation (Private) is associated with a higher odds of endometriosis (OR = 2.47, p = 0.014). 3.3. Bivariate Analysis of Clinical and Reproductive Factors Several clinical and reproductive variables were significantly associated with pel- vic endometriosis (Table 2 ). Table 2 . Clinical factors associated with pelvic endometriosis (Bivariate analysis). Variables Endometriosis Present (N = 99) n (%) Endometriosis Absent (N = 341) OR (95% CI) p-Value Age at menarche (years) ≤11 22 (22.2) 19 (5.6) 4.84 (2.50 - 9.39) 11 77 (77.8) 322 (94.4) 1 (reference) Cycle length (days) ≤27 48 (48.5) 51 (15.0) 5.35 (3.27 - 8.77) 27 51 (51.5) 290 (85.0) 1 (reference) Gravidity Nulligravid 49 (49.5) 102 (30.1) 1 (reference) Primigravid 19 (19.2) 88 (26.0) 0.45 (0.25 - 0.82) 0.009 Paucigravid 18 (18.2) 106 (31.3) 0.35 (0.19 - 0.65) <0.001 Multigravid 12 (12.1) 31 (9.1) 0.81 (0.38 - 1.70) 0.57 Grand multigravid 1 (1.0) 12 (3.5) 0.17 (0.02 - 1.37) 0.097 Parity Nulliparous 72 (72.7) 207 (60.7) 1 (reference) Primiparous 18 (18.2) 82 (24.0) 0.63 (0.35 - 1.12) 0.117 Pauciparous 9 (9.1) 42 (12.3) 0.62 (0.29 - 1.33) 0.216 Multiparous 0 (0.0) 10 (2.9) NA 0.965 T. N. Nana et al. DOI: 10.4236/ojog.2026.165067 694 Open Journal of Obstetrics and Gynecology Continued Familial endometriosis 12 (12.1) 0 (0.0) NA <0.001 Late menopause 5 (5.1) 0 (0.0) NA 0.976 Neoplasia 2 (2.0) 1 (0.3) 7.00 (0.63 - 77.97) 0.128 Lupus 1 (1.0) 0 (0.0) NA 0.225 Hypertension 1 (1.0) 10 (2.9) 2.96 (0.37 - 23.42) 0.469 Diabetes 0 (0.0) 2 (0.6) NA 1.000 Pelvic surgery 13 (13.1) 121 (35.5) 0.27 (0.15 - 0.51) <0.001 Abdominal surgery 2 (2.0) 26 (7.6) 0.25 (0.06 - 1.07) 0.058 Alcohol consumption 35 (35.4) 121 (35.5) 0.99 (0.62 - 1.59) 0.981 Tobacco smoking 3 (3.0) 6 (1.8) 1.75 (0.43 - 7.11) 0.432 Notes: 1) OR: Odds ratio; CI: Confidence interval , 2) Reference category indicated where applicable, 3) NA: Not applicable (cell count = 0, OR not estimable) , 4) Percentages are calculated per column, 5) Statistical significance set at p < 0.05. An age at menarche ≤ 11 years was associated with a nearly fivefold increased risk of endometriosis (OR = 4.84; 95% CI: 2.50 - 9.39; p < 0.001). Similarly, a men- strual cycle length ≤ 27 days significantly increased the odds of endometriosis (OR = 5.35; 95% CI: 3.27 - 8.77; p < 0.001). Conversely, primigravidity (OR = 0.45; 95% CI: 0.25 - 0.82; p = 0.009), pauci- gravidity (OR = 0.35; 95% CI: 0.19 - 0.65; p < 0.001), and a history of pelvic surgery (OR = 0.27; 95% CI: 0.15 - 0.51; p < 0.001) were associated with reduced odds of pelvic endometriosis. A family history of endometriosis was significantly associated with the condi- tion (p < 0.001). Other medical comorbidities and lifestyle factors, including hy- pertension, diabetes, alcohol consumption, and tobacco use, showed no signifi- cant association. 3.4. Multivariate Analysis of Factors Associated with Pelvic Endometriosis After adjustment for potential confounders in multivariate logistic regression analysis (Table 3 ), five variables remained independently associated with pelvic endometriosis. An age at menarche ≤ 11 years (aOR = 5.14; 95% CI: 2.49 - 10.64; p < 0.001) and a menstrual cycle length ≤ 27 days (aOR = 5.20; 95% CI: 2.91 - 9.30; p < 0.001) were independently associated with increased odds of pelvic endometriosis. T. N. Nana et al. DOI: 10.4236/ojog.2026.165067 695 Open Journal of Obstetrics and Gynecology Table 3 . Factors associated with endometriosis (Multivariate analysis). Variables Adjusted Odds Ratio (aOR) (95% Confidence Interval) p-Value Age at menarche (years) ≤11 5.14 (2.49 - 10.64) <0.001 Duration of cycle (days) ≤27 5.20 (2.91 - 9.30) <0.001 Gravidity Primigravid 0.49 (0.25 - 0.98) 0.045 Paucigravid 0.34 (0.16 - 0.70) 0.003 Pelvic surgery 0.30 (0.14 - 0.61) In contrast, a history of pelvic surgery (aOR = 0.30; 95% CI: 0.14 - 0.61; p < 0.001), primigravidity (aOR = 0.49; 95% CI: 0.25 - 0.98; p = 0.045), and paucigra- vidity (aOR = 0.34; 95% CI: 0.16 - 0.70; p = 0.003) were independently associated with reduced odds of endometriosis 4. Discussion 4.1. Summary of Findings This study found a surgical prevalence of pelvic endometriosis of 22.5% among women undergoing gynecological laparoscopy in three hospitals in Douala be- tween 2014 and 2022. This prevalence is consistent with the findings of Nana N. et al., who also reported a prevalence of 22.5% among women undergoing lapa- roscopy for chronic pelvic pain in Cameroon [10] . However, it is higher than the 3.12% prevalence reported by Bilkissou et al. [15]. These differences may reflect variations in study design and patient selection. While Bilkissou et al. included clinically diagnosed cases, the present study focused exclusively on women under- going laparoscopy, which likely increased the detection of endometriotic lesions. Histological confirmation was not performed systematically in our study. Nev- ertheless, among cases where biopsy was performed, histopathology confirmed endometriosis in 92% of cases. This high concordance between laparoscopic and histological findings may reflect the expertise of the surgeons performing the pro- cedures. McKee et al. reported that visual diagnosis during laparoscopy has high sensitivity but moderate specificity when compared with histological confirma- tion [16]. In contrast, Buchweitz et al. highlighted the variability in laparoscopic diagnosis and emphasized the importance of histological confirmation when fea- sible [17]. 4.2. Interpretation of Associated Factors Early menarche (≤11 years) and short menstrual cycle length (≤27 days) were strongly associated with pelvic endometriosis. Women with early menarche had T. N. Nana et al. DOI: 10.4236/ojog.2026.165067 696 Open Journal of Obstetrics and Gynecology approximately fivefold higher odds of endometriosis (AOR = 5.14; 95% CI: 2.49 - 10.64; p < 0.001), while those with shorter menstrual cycles had a similarly in- creased risk (AOR = 5.20; 95% CI: 2.91 - 9.30; p < 0.001). These findings are con- sistent with those reported by Burghaus et al., who identified early menarche and shorter menstrual cycles as important risk factors for the development of endo- metriosis [18]. From a pathophysiological perspective, early menarche increases lifetime exposure to estrogen, while shorter cycles increase the frequency of men- struation and the likelihood of retrograde menstruation, a central mechanism proposed in Sampson’s theory of endometriosis pathogenesis [19]. A history of pelvic surgery was inversely associated with endometriosis in the present study (AOR = 0.30; 95% CI: 0.14 - 0.61; p < 0.001). This finding contrasts with the results of Ashrafi et al., who reported pelvic surgery as a potential risk factor for endometriosis [20]. The observed inverse association should be inter- preted cautiously, as it may reflect reverse causation or selection bias rather than a true protective effect. Women with prior pelvic surgery may have undergone procedures for conditions unrelated to endometriosis, or surgical history may in- fluence referral patterns for laparoscopy. Similarly, primigravidity and paucigravidity were inversely associated with en- dometriosis. This observation aligns with findings from Ashrafi et al. , who re- ported a negative association between the number of pregnancies and endometri- osis [20]. Pregnancy reduces the number of menstrual cycles and is associated with prolonged exposure to progesterone, which exerts antiproliferative effects on endometrial tissue [21]. However, the relationship between pregnancy and endo- metriosis remains complex. A meta-analysis by Leeners et al. did not confirm a consistent protective effect of pregnancy, suggesting that residual confounding and reverse causation may influence these associations [22]. A family history of endometriosis was strongly associated with the disease in bivariate analysis (p < 0.001). However, this variable was not retained in the mul- tivariate model due to complete separation, as no cases were reported among the control group. This prevented reliable estimation of adjusted odds ratios. Previous studies have demonstrated that genetic susceptibility plays an important role in the development of endometriosis, with familial aggregation suggesting involve- ment of hormonal, inflammatory, and immune regulatory pathways [23] [24]. The association observed between private-sector employment and endometri- osis in bivariate analysis may reflect socioeconomic differences in access to healthcare. In many resource-limited settings, laparoscopic procedures may be more accessible to women with higher socioeconomic status, potentially leading to underdiagnosis among women in the informal sector. 4.3. Strengths and Limitations This study has several strengths. It included a relatively large sample size and in- volved three specialized healthcare facilities performing laparoscopic surgery, which enhances the reliability of the findings. In addition, all procedures were T. N. Nana et al. DOI: 10.4236/ojog.2026.165067 697 Open Journal of Obstetrics and Gynecology performed by experienced surgeons trained in minimally invasive gynecological surgery. However, some limitations should be acknowledged. The retrospective design may have introduced information bias due to incomplete documentation in med- ical records. Histological confirmation was not performed systematically in all cases, which may introduce some diagnostic misclassification. Furthermore, the study population consisted exclusively of women undergoing laparoscopy for spe- cific gynecological indications, which may limit the generalizability of the findings to the broader population. 5. Conclusion Pelvic endometriosis was identified in 22.5% of women undergoing gynecological laparoscopy in three tertiary hospitals in Douala, Cameroon. Early menarche (≤11 years) and shorter menstrual cycle length (≤27 days) were strongly associated with increased odds of endometriosis, while prior pelvic surgery and lower gravidity showed inverse associations. These findings provide insight into the surgical prev- alence and correlates of endometriosis among women undergoing laparoscopic evaluation in this urban Cameroonian setting. Improving access to laparoscopic diagnostic services and increasing clinical awareness may facilitate earlier detec- tion and management of endometriosis in similar resource-limited settings. Authors’ Contributions RT, TNN, AENT and FGMN conceptualized and designed the study. AEN, CNN, FKM, and CYN were responsible for participant recruitment at the study sites. AGS, ANN and HTN also contributed to participant recruitment and provided feedback on the manuscript. The manuscript was written by TNN, RT, CTN, and ETO. GHE, and CTN, ETO critically revised and reviewed the manuscript for im- portant intellectual content. All authors read and approved the final version of the manuscript. Conflicts of Interest Authors declare no conflicts of interest.

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