Menstruation is a normal physiological process that reflects the functional integrity of the female reproductive system and serves as an important indicator of women's health. The menstrual cycle is regulated through a complex interaction  between  the   hypothalamus,   pituit gland, ovaries and endometrium, collectively known as the hypothalamic–pituitary–ovarian axis. Normal menstrual function depends on the coordinated secretion of gonadotropins and ovarian hormones, resulting in cyclical endometrial changes and periodic menstrual bleeding [1-2]. According to the International Federation of Gynecology and Obstetrics (FIGO), a normal menstrual cycle is characterized by a cycle length of 24–38 days, menstrual bleeding lasting no more than eight days and relatively consistent cycle regularity [3]. Disturbances in menstrual frequency, duration, regularity, or volume are collectively categorized as menstrual disorders or abnormal uterine bleeding (AUB). These disorders represent one of the most common gynecological complaints among women of reproductive age and can significantly affect quality of life, productivity, psychological well-being and reproductive health [4-5]. Tubal ligation is one of the most widely used methods of permanent contraception worldwide. The procedure involves occlusion, ligation, cauterization, or removal of the fallopian tubes to prevent fertilization and subsequent pregnancy. Because of its high efficacy, safety profile and permanence, tubal ligation remains an important component of family planning programs in both developed and developing countries [6-7]. Although the procedure primarily targets the fallopian tubes and does not directly affect ovarian endocrine function, concerns have been raised regarding possible alterations in menstrual patterns following sterilization [8]. The concept of Post-Tubal Ligation Syndrome (PTLS) was introduced to describe a group of symptoms reportedly occurring after tubal sterilization, including heavy menstrual bleeding, menstrual irregularities, dysmenorrhea, pelvic pain and premenstrual symptoms [9]. Several investigators have suggested that disruption of the mesosalpinx during sterilization may affect ovarian blood supply and consequently influence ovarian hormone production, potentially contributing to menstrual disturbances [10]. However, other studies have failed to demonstrate significant differences in menstrual characteristics between women who underwent tubal ligation and those who did not, leading to ongoing controversy regarding the existence and pathophysiology of PTLS [11]. The Collaborative Review of Sterilization (CREST), one of the largest multicenter studies examining long-term outcomes after tubal sterilization, found limited evidence supporting a causal association between tubal ligation and subsequent menstrual abnormalities [12]. Nevertheless, conflicting findings continue to be reported in different populations, possibly due to variations in study design, patient selection, sterilization techniques, duration of follow-up and confounding factors such as age, parity, pre-existing gynecological disorders and discontinuation of hormonal contraceptive methods [8,11]. Given the continuing debate and the limited local data available, further investigation is required to clarify the relationship between tubal ligation and menstrual disorders. Understanding whether sterilized women experience different menstrual patterns compared with non-sterilized women is important for patient counseling, informed decision-making and postoperative follow-up. Therefore, the present study was conducted to compare menstrual patterns and associated clinical findings between post-tubal ligated women and non-tubal ligated women.

Patients and Methods

This case–control study was conducted at the Department of Obstetrics and Gynecology, Al-Imamein Al-Kadhimain Medical City, Baghdad, Iraq, between December 1, 2024 and October 31, 2025. A total of 200 women aged 30–45 years were enrolled and allocated into two groups: 100 women with a history of bilateral tubal ligation (BTL) (case group) and 100 women without a history of tubal ligation (control group). Participants were recruited from gynecology outpatient clinics and were evaluated for the presence of abnormal uterine bleeding (AUB) according to the International Federation of Gynecology and Obstetrics (FIGO) criteria.

Inclusion and Exclusion Criteria

Women aged 30–45 years with regular menstrual cycles before enrollment were eligible for inclusion. In the case group, participants had documented bilateral tubal ligation performed at least one year before recruitment. Women in the control group had no history of tubal sterilization or tubal surgery.

 Women were excluded if they had known coagulation disorders, were receiving anticoagulant therapy, had uterine malignancy, previous pelvic surgery other than BTL, recurrent pregnancy loss (≥3 abortions), uncontrolled diabetes mellitus, chronic renal or liver disease, thyroid disorders, pregnancy, lactation, current hormonal contraceptive use, or unilateral tubal ligation.

Data Collection and Clinical Assessment

Data were collected using a structured questionnaire that included demographic characteristics, obstetric and reproductive history, menstrual cycle characteristics, history of abnormal uterine bleeding, previous surgical procedures, contraceptive use and relevant medical conditions.

 All participants underwent comprehensive clinical evaluation, including general physical examination, abdominal examination and gynecological examination. Speculum examination was performed to assess the cervix and vagina for lesions, discharge, inflammation, or bleeding. Bimanual examination was conducted to evaluate uterine size, mobility, contour, adnexal masses and pelvic tenderness.

Laboratory Investigations

Laboratory investigations included complete blood count, hemoglobin concentration, platelet count, random blood sugar, liver function tests, coagulation profile (bleeding time, clotting time, prothrombin time, activated partial thromboplastin time and international normalized ratio), urinalysis and high vaginal swab when genital tract infection was suspected.

Ultrasonographic Assessment

All participants underwent pelvic ultrasonography using either transabdominal or transvaginal approaches according to clinical indications. Whenever possible, ultrasound examinations were performed during the early proliferative phase of the menstrual cycle (days 3–6) to standardize endometrial thickness measurements. Ultrasonographic evaluation included assessment of uterine morphology, endometrial thickness, uterine fibroids, adenomyosis, endometrial polyps, ovarian morphology and adnexal abnormalities. Findings were correlated with clinical manifestations and histopathological results when available.

Ethical Considerations

The study protocol was approved by the Scientific Council of Obstetrics and Gynecology, Iraqi Board for Medical Specializations. Written informed consent was obtained from all participants before enrollment. Participant confidentiality was maintained throughout the study and all procedures were conducted in accordance with the ethical principles of the Declaration of Helsinki.

Statistical Analysis

Data were analyzed using the Statistical Package for Social Sciences (SPSS) version 26. Continuous variables were expressed as mean±standard deviation (SD), while categorical variables were presented as frequencies and percentages. Comparisons between groups were performed using the independent-samples t-test for continuous variables and the Chi-square test or Fisher’s exact test for categorical variables. A p-value of <0.05 was considered statistically significant.

The age distribution was similar across all subgroups, with no statistically significant difference in mean age between post-BTL and non-BTL women, regardless of AUB status. Most participants—both with and without AUB—belonged to the 30–40-year age group, indicating comparability between the two populations. Key finding:  Age was not a confounding factor in the relationship between tubal ligation and AUB. (p = 0.312) Table 1.

Table 1:  Association of age between post-tubal ligated and non-tubal ligated groups among cases and controls

Parity distribution did not differ significantly between women with tubal ligation and the non-tubal ligation control group. High parity (≥4) was commonly observed across all groups, including women with AUB. No statistically significant association was found between parity and AUB in either group (p = 0.861). Figure 1

Figure 1: Association of Menstrual Disorders Between Post-Tubal Ligated and Non-Tubal Ligated Women with AUB

Various menstrual abnormalities including polymenorrhea, oligomenorrhea, menorrhagia and intermenstrual bleeding were compared between post-BTL and non-BTL women. There was no statistically significant difference in the distribution or type of menstrual disorders between the two groups. Key finding:  Tubal ligation was not associated with any specific pattern of menstrual abnormality. (p = 0.842) Table 2-3.

Table 2:  Association of Parity Between Groups

Table 3:   Association of Menstrual Disorders Between Groups

Mean endometrial thickness was compared across subgroups. There were no significant differences between post-BTL and non-BTL women, whether or not they had AUB.

Key finding: Endometrial thickness was not influenced by tubal ligation. (p = 0.901) Table 4and Figure 2.

Table 4: Endometrial Thickness

Figure 2: Association of Endometrial Thickness Between Post-Tubal Ligated and Non-Tubal Ligated Women with AUB

Endometrial biopsy was performed for all women with AUB.   Histopathological     patterns    including    proliferative,secretory, hyperplastic and atrophic endometrium were compared between groups. No statistically significant difference was observed between post-BTL and non-BTL women.

Key finding: Histopathological patterns of the endometrium did not differ between sterilized and non-sterilized women. Table 5 and Figure 3.

Table 5: Histopathological Findings

Figure 3: Histopathological Changes in Endometrium Among Women with AUB

 There was no significant association between the duration since BTL and the likelihood of developing AUB: < 5 years → 23.33% with AUB.  5–10 years → 40% with AUB 10 years → 36.67% with AUB. (p = 0.733). Key finding: The time since tubal ligation does not influence the probability of developing AUB Table 6 and Figure 4.

Table 6: Duration Since Tubal Ligation and Development of AUB

Figure 4: Association of Duration Since Tubal Ligation with Development of AUB

Table 7 and Figure 5 present the distribution of post-tubal ligated women according to the timing of their tubal ligation procedure and the presence or absence of abnormal uterine bleeding (AUB). Among women who developed AUB, interval tubal ligation was the most common type (43.33%), followed by postpartum (36.67%) and post-MTP ligation (20%). A similar pattern was observed among women without AUB, with interval ligation accounting for 45%, postpartum 30% and post-MTP 25%. (P:  0.634).

Table 7: Distribution of Post-Tubal Ligated Women According to Timing of Tubal Ligation and AUB

* Post-MTP: Post–Medical Termination of Pregnancy

Figure 5: Distribution of Post-Tubal Ligated Women According To Timing of Tubal Ligation and AUB

Moderate dysmenorrhea was the most frequently reported category in both groups, affecting 36.67% of post-BTL women and 35% of non-BTL women. Mild symptoms were reported equally in both groups (30%), while severe dysmenorrhea occurred slightly more often among post-BTL women (16.67% vs. 12.50%). Conversely, the absence of dysmenorrhea was somewhat more common in the non-BTL group (22.50% vs. 16.67%), p-value of 0.520. Table 8 and Figure 6.

Table 8: Association of Dysmenorrhea Severity between Post-BTL and Non-BTL Women with AUB

Figure 6: Association of Dysmenorrhea Severity between Post-BTL and Non-BTL Women with AUB

Table 9 compare the pattern of menstrual cycle regularity between women with previous tubal ligation (Post-BTL) and those without (Non-BTL). Regular menstrual cycles were reported by a slightly higher proportion of women in the non-ligated group (63%) compared to 54% in the post-BTL group, while irregular cycles were more   common   among   post-BTL

women (46% vs. 37%). Despite these numerical differences, the overall association was not statistically significant (p = 0.184).

Table 9:  Comparison of Menstrual Cycle Regularity Between Study Groups

Table 10 examine the association between intermenstrual bleeding and tubal ligation status. Intermenstrual bleeding was reported in 22% of women with prior tubal ligation compared to 16% of women without tubal ligation, while the majority of participants in both groups did not experience this symptom (78% vs. 84%). Although the proportion was slightly higher among post-BTL women, the difference was not statistically significant (p = 0.284).

Table 10:  Association of Intermenstrual Bleeding with Tubal Ligation Status

In the post-BTL group, the mean LH level was 9.8±3.2 mIU/mL in women with AUB compared with 8.7±2.8 mIU/mL in those without AUB. Similarly, in the non-BTL group, LH levels were 9.6±3.0 mIU/mL among women with AUB compared with 8.5±2.9 mIU/mL among those without AUB. Overall, LH levels were significantly higher in women presenting with AUB (p = 0.012).  In contrast, no statistically significant difference was observed in FSH levels between the groups. In the post-BTL group, the mean FSH level was 6.4±1.9 mIU/mL in women with AUB and 6.0±1.6 mIU/mL in those without AUB, while in the non-BTL group the mean values were 6.3±1.8 mIU/mL and 6.2±1.7 mIU/mL, respectively. Notably, AMH levels were lower among women with AUB compared with women without AUB in both groups. In the post-BTL group, AMH levels were 2.0±1.0 ng/mL in women with AUB compared with 2.6±1.2 ng/mL in those without AUB. Likewise, in the non-BTL group, the mean AMH level was 2.2±1.1 ng/mL in women with AUB compared with 2.9±1.3 ng/mL among women without AUB. Overall, this difference was statistically significant (p = 0.001). These findings are summarized in Table 11-12.

Table 11: Comparison of LH, FSH and AMH Levels According to AUB Status

Table 12: Comparison of Endometrial Abnormalities on Ultrasound Among Subgroups

Ultrasonography revealed structural abnormalities such as fibroids, polyps, adenomyosis, or ovarian cysts. While ultrasound-detected abnormalities were significantly associated with AUB, they were not associated with BTL status. Key finding: Ultrasonographic abn1rmalities correlated with AUB but not with prior tubal ligation. (p significant for AUB association; p = NS for BTL association).

In the current study, age distribution was comparable across post-BTL and non-BTL groups, both among women with AUB and those without. The majority of participants clustered within the 30–40-year age range, corresponding to the late reproductive and early perimenopausal years—a period during which menstrual irregularities become increasingly prevalent due to physiological hormonal fluctuations. These findings are consistent with studies conducted in India, Iran and Pakistan, which similarly reported that menstrual complaints following tubal ligation tend to occur during the late reproductive years rather than as a direct consequence of the procedure itself. Verma et al. reported no significant causal relationship between tubal ligation and menstrual disorders after adjustment for age and baseline characteristics [12]. Similarly, Sadatmahalleh et al. found that changes in menstrual patterns were more strongly associated with advancing age and pre-existing menstrual characteristics than with sterilization itself [13]. Mangla and Singla also demonstrated that menstrual abnormalities were not significantly more common among women who underwent tubectomy than among non-ligated controls [14]. Abbas et al. further emphasized the multifactorial nature of post-ligation menstrual complaints [15]. Parity distribution did not differ significantly between women with and without tubal ligation. High parity was frequently observed in both groups and no statistically significant association was found between parity and AUB. Similar observations have been reported by Desai et al. and Chhabra and Mishra, who concluded that parity alone does not increase the risk of menstrual disorders after sterilization [16-17]. Comparable findings were also reported by Shaikh and Naqvi et al. [18-19]. Qualitative analysis of menstrual abnormalities, including polymenorrhea, oligomenorrhea, menorrhagia and intermenstrual bleeding, revealed no statistically significant differences between post-BTL and non-BTL women. Polymenorrhea and menorrhagia were the most frequently reported patterns in both groups. These findings support the concept that menstrual disturbances are primarily related to endocrine and structural factors rather than tubal occlusion itself. Similar conclusions were reported by Verma et al., Abbas et al. Desai et al. and Chhabra and Mishra [12,15-17]. Large epidemiological studies by Harlow et al. and Wilcox et al. also demonstrated that tubal sterilization does not independently increase the risk of menorrhagia or dysmenorrhea after controlling for confounding factors [20-21]. Although Yasmeen et al. and Naqvi et al. reported higher frequencies of menstrual complaints among sterilized women, these findings may reflect discontinuation of hormonal contraception, selection bias, or unrecognized gynecological disease rather than a direct effect of tubal ligation [22,19]. Ultrasonographic evaluation revealed that adenomyosis, uterine fibroids, endometrial polyps and ovarian cysts were significantly associated with AUB, whereas no relationship was observed between these abnormalities and tubal ligation status. These findings are in agreement with the FIGO PALM–COEIN classification system, which identifies structural uterine pathology as a major cause of abnormal uterine bleeding [23-24]. Similar observations have been reported in recent imaging-based studies evaluating women with AUB [25-26]. Mean endometrial thickness did not differ significantly between post-BTL and non-BTL women with AUB. Histopathological examination similarly revealed comparable distributions of proliferative, secretory, hyperplastic, inflammatory and mixed endometrial patterns. These findings are consistent with those reported by Desai et al. and Chhabra and Mishra, who found no significant histopathological changes attributable to tubal sterilization [16-17]. Heremans et al. highlighted the importance of standardized ultrasound timing when evaluating endometrial thickness [27], while Rathi and Wagh demonstrated that structural abnormalities identified by ultrasonography are independent of sterilization status [28]. The present study found no significant association between duration since tubal ligation and the occurrence of AUB. Women sterilized less than five years previously demonstrated menstrual patterns comparable to those sterilized for more than ten years. These findings agree with Langton et al., who found no significant reduction in ovarian reserve markers after tubal ligation [29]. Similar conclusions were reported in contemporary studies assessing ovarian function following sterilization [30]. The concept of post-tubal ligation syndrome remains controversial. The current findings do not support the existence of a distinct syndrome characterized by menstrual abnormalities following sterilization. Instead, the observed menstrual disturbances appear to be attributable to common gynecological conditions, endocrine dysfunction, aging and structural uterine abnormalities rather than the sterilization procedure itself. This conclusion is consistent with the majority of contemporary evidence evaluating menstrual outcomes after tubal ligation [12-17,20-21]. The results of this study reinforce the safety of bilateral tubal ligation as a permanent contraceptive method. Women presenting with menstrual abnormalities after sterilization should undergo comprehensive evaluation for endocrine disorders and structural uterine pathology rather than having symptoms attributed directly to tubal ligation. Appropriate counseling before and after sterilization may help reduce misconceptions regarding the so-called post-tubal ligation syndrome.

The findings of the present case–control study indicate that bilateral tubal ligation (BTL) is not associated with an increased risk of abnormal uterine bleeding (AUB) or menstrual disorders. Women with previous tubal ligation demonstrated menstrual patterns comparable to those observed among non-ligated women, suggesting that the sterilization procedure itself does not adversely affect menstrual function. No significant differences were identified between women with and without BTL regarding age distribution, parity, endometrial thickness, or endometrial histopathological findings. Likewise, the frequency and pattern of menstrual abnormalities, including menorrhagia, polymenorrhea, oligomenorrhea and intermenstrual bleeding, were similar between the two groups. Ultrasonographic evaluation revealed that structural gynecological abnormalities such as uterine fibroids, adenomyosis, endometrial polyps and ovarian lesions were significantly associated with abnormal uterine bleeding regardless of tubal ligation status. These findings emphasize that structural uterine and ovarian pathology rather than sterilization itself represents the major contributor to menstrual disturbances. Hormonal assessment demonstrated significantly higher luteinizing hormone (LH) levels and significantly lower anti-Müllerian hormone (AMH) levels among women with AUB, suggesting a possible role of altered ovarian endocrine function in the pathogenesis of abnormal uterine bleeding. However, these hormonal changes were not specifically related to previous tubal ligation. Furthermore, the duration elapsed since tubal ligation showed no significant relationship with menstrual abnormalities or AUB. Collectively, the findings of this study do not support the existence of a clinically significant post-tubal ligation syndrome and reinforce the safety of bilateral tubal ligation as an effective method of permanent contraception.

Recommendations

Based on the findings of the current study, women presenting with abnormal uterine bleeding after tubal ligation should undergo a comprehensive clinical evaluation rather than having their symptoms attributed directly to the sterilization procedure. Careful assessment should include detailed history taking, physical examination, hormonal evaluation and imaging studies to identify potential underlying causes of bleeding abnormalities. Pelvic ultrasonography should be routinely considered in women with AUB because structural abnormalities such as fibroids, adenomyosis, endometrial polyps and ovarian cysts were found to be significantly associated with abnormal bleeding patterns. In addition, endometrial sampling should be performed in women aged 40 years or older, those with persistent or unexplained AUB and women with risk factors for endometrial pathology. Healthcare providers should offer comprehensive counseling to women considering bilateral tubal ligation, emphasizing its effectiveness and safety as a permanent contraceptive method and explaining that current evidence does not support a causal relationship between tubal ligation and long-term menstrual disturbances. Appropriate counseling may help reduce misconceptions and alleviate unnecessary concerns regarding post-tubal ligation syndrome. Future research should include larger multicenter prospective studies with longer follow-up periods to further evaluate menstrual outcomes after sterilization. Additional studies incorporating detailed hormonal profiling, ovarian reserve markers and quality-of-life assessments are recommended to better understand the complex factors influencing menstrual health in women undergoing tubal ligation.

Limitations of the Study

Several limitations should be considered when interpreting the findings of this study. First, the study was conducted at a single tertiary healthcare center, which may limit the generalizability of the results to other populations and healthcare settings. Second, the case–control design allows assessment of associations but does not establish a definitive causal relationship between tubal ligation and menstrual outcomes. Another limitation is the reliance on participant recall for certain aspects of menstrual and reproductive history, which may introduce recall bias. In addition, detailed pre-sterilization menstrual data were not available for all participants, limiting direct comparison of menstrual characteristics before and after tubal ligation. Although the sample size was adequate for the primary objectives of the study, it may have been insufficient to detect subtle differences in less common menstrual abnormalities. Furthermore, psychological factors, quality-of-life measures and patient perceptions regarding menstrual changes were not assessed and may have influenced symptom reporting. Finally, longitudinal hormonal measurements before and after tubal ligation were unavailable, preventing direct evaluation of endocrine changes over time following the procedure.

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