Vol.:(0123456789) Obesity Surgery (2025) 35:3149–3156 https://doi.org/10.1007/s11695-025-08012-2 RESEARCH The Influence of Bariatric Surgery on Reproductive Hormones and Ovarian Morphology and Clinical Findings in Women: A Prospective Study Yagmur Soykan1 · Hüseyin Bayhan1 · Serkan Akogul2 · Abdulkadir Bedirli1 Received: 17 February 2025 / Revised: 14 May 2025 / Accepted: 16 June 2025 / Published online: 24 June 2025 © The Author(s) 2025 Abstract Background Obesity in women of reproductive age often causes hormonal imbalances and fertility issues. Bariatric surgery effectively promotes weight loss and metabolic improvement, but its impact on reproductive hormones warrants further investigation. This study examines bariatric surgery’s effects on hormonal and clinical changes in women preoperatively and at 3 and 6 months postoperatively. Methods This prospective study included 67 women undergoing bariatric surgery. Anthropometric measurements, hormo- nal profiles, ovarian morphology(via ultrasonography), and the presence of hirsutism and dysmenorrhoea were evaluated preoperatively and at 3- and 6-month follow-ups. Results Bariatric surgery resulted in significant weight loss and hormonal changes. Body weight (p < 0.001) and BMI (p < 0.001) decreased substantially, with the most rapid reduction occurring in the first 3 months, followed by a slower decline. Androstenedione levels decreased significantly (p < 0.001). Total testosterone levels showed a significant reduction at 6 months (p < 0.001), while SHBG (p < 0.001; p = 0.014), DHEA-S, and AMH (p < 0.001; p < 0.001; p = 0.014) levels increased. No significant changes were observed in FSH and LH levels (p > 0.05). The severity of dysmenorrhea decreased significantly at 6 months (p < 0.001). Additionally, the prevalence of hirsutism (p < 0.001) and polycystic ovary (PCO) mor- phology (p < 0.001) decreased significantly at 6 months. Conclusions Bariatric surgery significantly decreases testosterone and androstenedione, while increasing AMH, DHEA-S, and SHBG. Improvements in PCO morphology, dysmenorrhea, and hirsutism highlight the effects of bariatric surgery on hormonal balance and reproductive health. Keywords Bariatric surgery · Ovarian hormones · Adrenal androgens · Hirsutism · Dysmenorrhea · Polycystic ovary Introduction Obesity is a growing global health concern, with its increas- ing prevalence linked to hormonal imbalances, metabolic disorders, and adverse effects on reproductive function [1]. In women of reproductive age, obesity significantly disrupts hormonal balance, particularly in the ovarian and adrenal glands. Ovarian hormones—such as estrogen, progesterone, and testosterone—are essential for reproductive health and overall well-being. Additionally, adrenal hormones—includ- ing cortisol, dehydroepiandrosterone sulfate (DHEA-S), and androgens—play key roles in metabolism, stress response, and sex hormone production [2]. By disturbing the balance of these hormones, obesity markedly increases the risk of complications such as polycystic ovary syndrome (PCOS), * Yagmur Soykan dr.soykan@hotmail.com Hüseyin Bayhan drhuseyinbayhan@gmail.com Serkan Akogul sakogul@pau.edu.tr Abdulkadir Bedirli bedirlia@gazi.edu.tr 1 Gazi University, Ankara, Turkey 2 Pamukkale University, Denizli, Turkey http://crossmark.crossref.org/dialog/?doi=10.1007/s11695-025-08012-2&domain=pdf 3150 Obesity Surgery (2025) 35:3149–3156 infertility, pregnancy-related issues, and cardiovascular dis- eases in women of reproductive age. Bariatric surgery is one of the most effective treatments for morbid obesity and is considered an advanced therapeu- tic option. Various bariatric surgery techniques—including gastric bypass, sleeve gastrectomy, and adjustable gastric banding—promote weight loss through different mecha- nisms, leading to significant metabolic improvements. These surgical procedures facilitate weight loss and improve obe- sity-related comorbidities, such as type 2 diabetes (T2D), through complex mechanisms beyond simple caloric restric- tion and malabsorption. These include favorable alterations in gut hormone secretion (e.g., increased GLP-1 and PYY), changes in bile acid profiles, modulation of the gut microbi- ome, and potentially increased energy expenditure [3]. These physiological changes contribute to enhanced insulin sen- sitivity and glucose homeostasis, and may exert beneficial effects on reproductive health. Indeed, the positive impact of bariatric surgery on reducing infertility and improving pregnancy outcomes in obese women has been previously demonstrated through systematic reviews and meta-analyses [4, 5]. These studies highlight that weight loss following bar- iatric surgery contributes to the improvement of ovulatory dysfunction and irregular menstruation, thereby increasing spontaneous conception rates and reducing miscarriage rates [4, 5]. Similarly, Babarinsa et al. have reported that bariatric surgery has positive effects on fertility and sexuality[6]. Postoperative weight loss has been associated with nota- ble hormonal changes. In particular, improvements in PCOS symptoms—such as reduced insulin resistance, lower andro- gen levels, regulated ovulation, and alleviated menstrual irregularities—have been observed. Furthermore, bariatric surgery has been linked to improved pregnancy outcomes [7]. However, the hormonal effects of bariatric surgery are complex, and ongoing research aims to further elucidate these mechanisms. Key areas requiring clarification include long-term hormonal changes following bariatric surgery and variations in outcomes based on individual patient characteristics. This study aims to comprehensively evaluate the effects of bariatric surgery on clinical, biochemical, and radiologi- cal outcomes in women of reproductive age. Specifically, it will analyze weight loss, ovarian and adrenal hormone levels, ovarian morphology, and clinical findings following bariatric surgery. Materials and Methods The study included female patients aged 18 to 49 years with a body mass index (BMI) of 35 and higher who were sched- uled to robotic bariatric surgery by the General Surgery Clinic. Participants were selected from those referred to the Gynaecology and Obstetrics Clinic for gynecological com- plaints during the preoperative evaluation process. Demo- graphic data, medical history, and gynecological history were recorded for all patients meeting the inclusion criteria. Patients using hormonal contraceptives (due to their influ- ence of sex steroid hormone levels) and those with a history of ovarian surgery (due to its impact on Anti-Müllerian Hor- mone [AMH] levels) were excluded from the study. Blood samples were collected at three time points: preoperatively, and at 3 and 6 months postoperatively, for hormonal analy- sis. The levels of Follicle-Stimulating Hormone (FSH), Luteinizing Hormone (LH), Sex Hormone-Binding Globulin (SHBG), total testosterone, androstenedione, DHEA-S, and AMH were measured. The severity of hirsutism was assessed using the Ferri- man-Gallwey score, while the severity of dysmenorrhea was evaluated based on the patient’s self-reported pain score as determined by a numeric rating scale (NRS)[8]. Polycystic ovary (PCO) was diagnosed via ultrasound. It is character- ized by the presence of hyperechoic central stroma, periph- eral follicle distribution (string of pearls sign), and multiple follicles of uniform size (diameter: 2–9 mm). All patients were closely monitored throughout the study period. Blood samples were collected preoperatively and at 3 and 6 months postoperatively for hormonal assessments, and gynecological examinations were conducted at each time point. Participants whose blood samples could not be obtained at the scheduled time points or whose hormone levels could not be evaluated were excluded from the study. Statistical Analysis Statistical analyses were performed using IBM SPSS Sta- tistics 29 software. Categorical variables were presented as with frequency and percentage (%), while numerical varia- bles were reported as mean ± standard deviation and median (min–max) values. Kolmogorov–Smirnov normality test was used to assess the distribution characteristics of continuous variables. Nonparametric analysis methods were applied for data that did not follow a normal distribution. To analyze changes in dependent numerical variables over time, the non-parametric Friedman test was employed for repeated measures analysis. If a significant difference was detected post hoc Wilcoxon tests and Bonferroni correction were conducted to determine which time points differed. For binary categorical dependent variables measured over time, Cochran’s Q test was used to assess differences. If sig- nificant results were obtained, the post hoc McNemar test and Bonferroni correction were applied. A p-value of < 0.05 was considered statistically significant in all analyses. 3151Obesity Surgery (2025) 35:3149–3156 Results A total of 67 female patients participated in this study. Vari- ables were measured preoperatively and at 3 and 6 months postoperatively in women with a BMI of 35 or higher The distribution of these variables is summarized in Table 1. According to Table  1, 76.7% of patients underwent robotic Roux-en-Y gastric bypass surgery, while 23.9% underwent robotic sleeve gastrectomy. Comorbidities were present in 32.8% of participants, with the most common being diabetes (10.4%), hypothyroidism (9.0%), asthma (6.0%), and hypertension (1.5%). The remaining 67.2% had no comorbidities. Regarding educational background, 43.3% of patients were high school graduates, 35.8% held a uni- versity degree, 13.4% had completed primary school, and 7.5% had completed secondary school. The mean age of participants was 32.72 ± 8.5 years, with an average height of 1.63 ± 0.06 m and a mean weight of 112.34 ± 19.32 kg. In this study, preoperative, 3rd-month, and 6th-month measurements of weight, BMI, FSH, LH, total testosterone, AMH, DHEA-S, SHBG, and androstenedione and dysmen- orrhea were evaluated using the Kolmogorov–Smirnov test, which indicated that these variables were not normally dis- tributed (p < 0.05). Accordingly, the nonparametric Fried- man test was used to analyze the changes over time. For variables showing significant differences in the Friedman test, post hoc Wilcoxon tests with Bonferroni corrections were applied to determine differences between time points. The results of these analyses are presented in Table 2. Significant reductions in both weight and BMI were observed following surgery (p < 0.001), with the most rapid decline occurring between the preoperative period and 3 months post-surgery. This was followed by a slower yet still significant decrease from 3 to 6 months. These changes were statistically significant at all time points compared to baseline, as well as between the three- and six-month measurements. A statistically significant difference in androstenedione levels was observed among the preoperative, 3-month, and 6-month measurements (p < 0.001). Compared to preop- erative levels, mean androstenedione levels decreased sig- nificantly at 3 and 6 months. The reductions between the preoperative period and postoperative time points were sta- tistically significant, as was the decrease between the 3rd and 6th months. A statistically significant difference in total testosterone levels was observed among the preoperative, 3-month, and 6-month measurements (p < 0.001). While no significant dif- ference was found between the preoperative and 3-month levels, total testosterone levels significantly decreased by the 6th month compared to both the preoperative period and the 3rd month. A statistically significant increase in SHBG levels was observed between the preoperative period and the 3rd and 6th months (p < 0.001; p = 0.014). While no significant dif- ference was found between the preoperative and 3rd-month levels, SHBG levels at the 6th month were significantly higher than those in both the preoperative period and the 3rd month. A statistically significant difference in  DHEA- S and AMH levels was observed between the preoperative period and the 3rd and 6th months (p < 0.001; p < 0.001; p = 0.014). Mean DHEA-S and AMH levels increased between the 3rd and 6th months compared to preoperative levels. While no statistically significant difference was found between the preoperative period and the 3rd month, levels at the 6th month were significantly higher than both the preop- erative and 3rd-month values. No statistically significant differences were observed in FSH and LH levels among the preoperative, 3rd-month, and 6th-month measurements (p > 0.05). Mean FSH and LH levels at 3 and 6 months post-bariatric surgery remained similar to preoperative values. In the analysis of dysmenorrhea severity, statistically significant differences were found between preoperative, Table 1 Distribution of findings regarding the study Variable n % Type of surgery Robotic sleeve gastrectomy 16 23.9 Robotic Roux-en-Y gastric bypass 51 76.7 Disease None 45 67.2 Present 22 32.8 Type of disease None 45 67.2 Diabetes mellitus (DM) 7 10.4 Hypothyroidism 6  9  Asthma 4  6 Hypertension (HT) 1 1.5 HT + DM 3 4.5 HT + DM + hypothyroidism 1 1.5 Education status Primary school 9 13.4 Secondary school 5 7.5 High school 29 43.3  University 24 35.8 Parameter  Mean ± SS  Median [min– max] Age (year) 32.72 ± 8.49 31 [18–49] Heights (meters) 1.63 ± 0.06 1.63 [1.50–1.78] Weights (kg) 112.34 ± 19.32 109 [80–165]  3152 Obesity Surgery (2025) 35:3149–3156 three-month, and six-month data (p < 0.001). Compared to preoperative levels, there was a significant decrease in mean dysmenorrhea severity at 3 and 6 months. The dif- ferences between the preoperative period and the 3rd and 6th months were statistically significant, indicating that dysmenorrhea severity decreased notably between the 3rd and 6th months. In this study,  preoperative, 3-month, and 6-month data were compared to assess the effects of bariatric sur- gery on hirsutism (absent/present) and polycystic ovary (PCO) appearance. Cochran’s Q test was used for statistical analysis, and in cases of significant results, post hoc McNe- mar test with Bonferroni correction was applied. The find- ings from these analyses are presented in Table 3. A statistically significant difference was observed in the prevalence of hirsutism between preoperative data and the measurements taken at 3 months and 6 months (p < 0.001). Post hoc analyses indicated that the differences between the preoperative period and the 6-month data, as well as between the 3-month and 6-month data, were significant (p < 0.05); however, no significant difference was found between the preoperative period and the 3-month data (p > 0.05). Overall, Table 2 Friedman test results of repeated measures of variables Bold values indicate statistically significant results (p <0.05) Follow-up Mean ± SS Median [min–max] Friedman test Post hoc Bonferroni Weight (kg) Preop 3rd month 6th month 112.34 ± 19.32 87.12 ± 13.70 71.66 ± 11.40 109 [80–165] 83 [68–126] 68 [54–98] χ2 = 134 p < 0.001 Preop > 3rd month Preop > 6th month 3rd month > 6th month BMI (kg/m2) Preop 3rd month 6th month 42.25 ± 7.74 32.78 ± 5.60 26.97 ± 4.67 41 [30.6–71.1] 31.5 [23.4–55.6] 26.3 [19.4–43.6] χ2 = 134 p < 0.001 Preop > 3rd month Preop > 6th month 3rd month > 6th month Androstenedione Preop 3rd month 6th month 2.41 ± 1.29 2.26 ± 1.23 2.06 ± 0.97 2.22 [0.30–7.25] 2 [0.26–6.60] 1.87 [0.43–5.70] χ2 = 31.731 p < 0.001 Preop > 3rd month Preop > 6th month 3rd month > 6th month Total testosterone Preop 3rd month 6th month 0.58 ± 0.30 0.53 ± 0.30 0.45 ± 0.26 0.54 [0.10–1.29] 0.46 [0.10–1.54] 0.38 [0.10–1.16] χ2 = 45.608 p < 0.001 Preop = 3rd month Preop > 6th month 3rd month > 6th month SHBG Preop 3rd month 6th month 35.54 ± 31.47 38.04 ± 32.33 46.32 ± 33.80 26.5 [9.3–186] 32 [8.2–198] 43 [8.60–189] χ2 = 56.448 p < 0.001 Preop = 3rd month Preop < 6th month 3rd month < 6th month DHEA-S Preop 3rd month 6th month 229.72 ± 133.45 237.46 ± 123.90 249.43 ± 124.07 206 [14–511] 230 [22–467] 244 [44–486] χ2 = 25.642 p < 0.001 Preop = 3rd month Preop < 6th month 3rd month < 6th month AMH Preop 3rd month 6th month 3.63 ± 3.91 3.82 ± 4.11 4.03 ± 4.27 2.89 [0.1–21.5] 2.84 [0.1–22] 3.00 [0.1–22.5] χ2 = 8.475 p = 0.014 Preop = 3rd month Preop < 6th month 3rd month = 6th month FSH Preop 3rd month 6th month 8.64 ± 4.16 8.59 ± 4.28 8.40 ± 4.40 7.8 [1.71–22.32] 8 [2–21.8] 7.86 [1.98–24] χ2 = 2.239 p = 0.326 - LH Preop 3rd month 6th month 7.57 ± 4.07 7.70 ± 4.22 7.77 ± 5.03 6.82 [0.71–20.82] 7 [1.6–22] 6.7 [1.24–27.49] χ2 = 2.179 p = 0.336 - Dysmenorrhoea Preop 3rd month 6th month 3.64 ± 3.03 2.67 ± 2.57 1.66 ± 2 4 [0–10] 2 [0–10] 1 [0–8] χ2 = 76 p < 0.001 Preop > 3rd month Preop > 6th month 3rd month > 6th month Table 3 Cochran’s Q test results of variables Bold values indicate statistically significant results (p <0.05) Follow-up Negative N (%) Positive N (%) Cochran’s Q test Post hoc Bonferroni Hirsutism Preop 3rd month 6th month 51 (%77) 51 (%77) 58 (%87) 16 (%23) 16 (%23) 9 (%13) Q = 14 p < 0.001 Preop = 3rd month Preop ≠ 6th month 3rd month ≠ 6th month PCO morphology Preop 3rd month 6th month 38 (%57) 43 (%65) 49 (%74) 29 (%43) 24 (%35) 18 (%26) Q = 16.55 p < 0.001 Preop = 3rd month Preop ≠ 6th month 3rd month = 6th month 3153Obesity Surgery (2025) 35:3149–3156 the change in hirsutism following bariatric surgery did not show significant improvement until the 3-month mark, but a noteworthy decrease was observed by the 6-month point. These findings suggest that the effect of bariatric surgery on hirsutism increases over time, providing a statistically significant reduction, particularly at 6 months. A statistically significant difference was found in the fre- quency of PCO appearance between the preoperative period, as well as the 3-month and 6-month data (p < 0.001). Post hoc analyses indicated a significant difference between the preoperative period and the 6th month (p < 0.05); however, no significant difference was noted between the preopera- tive period and the 3rd month or between the 3rd month and the 6th month (p > 0.05). Overall, a decrease in the appear- ance of PCO was noted in the first 3 months after bariatric surgery, but no significant change was observed, while a significant decrease occurred by the 6th month compared to the preoperative period. Discussion As research on hormonal changes following bariatric sur- gery continues to expand, our study makes a unique con- tribution to the literature by incorporating ultrasonographic evaluation of ovarian morphology and examining gyneco- logical clinical findings, alongside a comprehensive hor- monal analysis. Excess body fat in obese patients can disrupt the hypo- thalamic-pituitary–gonadal (HPG) axis through both cen- tral and peripheral mechanisms [9]. Dysregulation of this axis can lead to  anovulation, infertility, and menstrual irregularities [7]. Weight loss is believed to have beneficial effects by regulating the menstrual cycle, enhancing ovula- tory function, and improving fertility in obese women [4]. As a result, bariatric surgery is recommended for patients with a body mass index (BMI) ≥ 40 kg/m2 or a BMI of 35–39.9 kg/m2 with comorbidities, particularly when con- ventional interventions such as diet, exercise, and pharma- cological treatments have been unsuccessful [10]. Although the literature presents varying findings on the effects of bariatric surgery on the hormonal axis, our study revealed no significant changes in FSH and LH levels. Spe- cifically, FSH and LH levels remained stable between pre- operative measurements and those taken at 3 and 6 months postoperatively. Previous studies have reported inconsist- ent results  regarding FSH and LH levels after bariatric surgery. In a study by Santaro et al., obese women were found to have irregular and prolonged menstrual cycles, along with decreased urinary levels of luteinizing hor- mone (LH), follicle-stimulating hormone (FSH), estrogen metabolites, and progesterone  [11]. Conversely, Emami et al. reported that after bariatric surgery, LH, FSH, and SHBG levelssignificantly increased, while estradiol (E2) lev- els decreased in women [12]. Similarly, in a study by Paul et al., estradiol, progesterone, LH, and FSH levels remained unchanged compared to preoperative values [13]. How- ever, Anbara et al.found that FSH and LH levels increased at 3 and 6 months postoperatively, while estrogen and pro- gesterone levels remained unchanged at 3 months after surgery [14]. These inconsistencies may be due to the fact that FSH and LH are less affected by weight loss follow- ing bariatric surgery. Increased adipose tissue in obesity enhances aromatase enzyme activity, leading to higher estro- gen production. It is suggested that the variability in estra- diol levels across studies may stem from individual patient differences. Sex Hormone Binding Globulin (SHBG) is a circulat- ing protein that transports sex hormones in the blood, pri- marily testosterone and estradiol, the two most critical sex hormones. However, SHBG can also bind to other steroid hormones, such as dihydrotestosterone (DHT) and andros- tenedione, albeit with lower affinity. Excess weight, particu- larly visceral fat (fat surrounding the abdominal organs), is a major contributor to insulin resistance. Following bariatric surgery, weight loss leads to a decrease in insulin resistance. Consequently, SHBG (sex hormone-binding globulin) levels increase, binding more testosterone and thereby reducing the amount of free, biologically active testosterone. Bari- atric surgery has been shown to decrease androstenedione and total testosterone levels in women [12]. In our study, we observed a statistically significant increase in SHBG levels at 6 months postoperatively, following weight loss. Consistent with previous findings, our study observed a sig- nificant reduction in total testosterone and androstenedione levels as weight loss progressed. These results further sup- port the role of bariatric surgery in lowering androgen lev- els. Similarly, in a study involving 100 women after gastric bypass, a significant drop in testosterone levels was observed alongside a notable increase in SHBG [13]. Additionally, in the study by Lv et al., bariatric surgery led to decreased lev- els of total testosterone, DHEA, and estradiol, while SHBG levels increased, a change that was associated with a reduc- tion in the incidence of abnormal menstruation [15]. The observed increase in SHBG and decrease in androgen lev- els following bariatric surgery underlines the importance of understanding the hormonal effects of this procedure and emphasizes the need for additional replacement therapy tai- lored to individual needs. Our study evaluated  ovarian morphology via ultra- sonography during the preoperative period and at 3 and 6 months postoperatively. During the preoperative assess- ment, 43% of the women exhibited ultrasonographic signs of PCO. While no significant change in ovarian morphol- ogy was observed at 3 months postoperatively, the propor- tion of women with PCO appearance decreased to 27% at 3154 Obesity Surgery (2025) 35:3149–3156 the 6th-month follow-up. The absence of a statistically significant change at 3 months suggests that the effects of hormonal changes and weight loss on ovarian morphol- ogy may take longer to manifest, indicating no substan- tial structural improvement in the short-term. Similarly, a study by Singh et al. reported PCO in 77% of women (14 out of 18) before bariatric surgery, with complete recov- ery observed in 55% of these women during the one-year postoperative follow-up [16]. Various studies have dem- onstrated that bariatric surgery reduces ovarian volume in women with PCOS. In a study conducted on obese and infertile women with PCOS, bariatric surgery was shown to restore physiological balance by significantly reducing ovarian volume, a finding supported by ultrasonographic evaluations [17]. A gradual reduction in ovarian morphol- ogy and volume was observed, with the mean ovarian vol- ume decreasing from 14.7 ± 1.79 ml to 9.78 ± 1.19 ml at 6 months postoperatively, and further to 8.15 ± 0.99 ml 1  year later, ref lecting a  significant and ongoing decrease (p < 0.001) [17]. Supporting these findings, Singh et al. found ultrasonographic signs of PCO in 77% (14/18) of women before bariatric surgery, with complete resolu- tion in 55% (4/7) of these women at the one-year follow- up.However, in a study by  Christ and Falcone, which evaluated 44 women with PCOS and 65 controls, ovarian volume did not show a significant decrease after surgery in either group [15]. This suggests that the effects of bariatric surgery on PCOS may vary depending on patient popula- tion and study methodology. Research suggests that bari- atric surgery  may lead to  reduced insulin resistance, improved hirsutism scores, and enhanced menstruation and ovulation in women with PCOS [18]. In addition to these beneficial effects, alterations in reproductive hormones, particularly anti-Müllerian hormone (AMH), are also of great importance. In our study, no statistically significant difference was observed between preoperative AMH lev- els and those measured 3 months after bariatric surgery, regardless of PCO appearance on ultrasound. However, at 6 months post-surgery, AMH levels showed a significant increase compared to both the preoperative period and 3rd month postoperative levels. A similar study by Pilone et al. analyzed AMH values in 53 patients before sleeve gastrectomy and at 3 and 6 months postoperatively, find- ing no significant change between baseline and  three- month values, but a notable rise in AMH levels 6 months after the operation [19]. In contrast, a study by  Lv et al. reported a decrease in AMH levelsfollowing bariat- ric surgery [15]. Additionally, Merhi et al. examined AMH levels in 16 women before and after bariatric surgery, not- ing a significant reduction in patients under 35 years of age, while no decrease was observed in women older than 35 years [20]. The disparity in findings across these stud- ies may be attributed to factors such as age, the presence of PCOS, and individual physiological responses to surgery. Therefore, while AMH levels provide valuable insights into ovarian reserve and function, they should not be interpreted in isolation. The reduction of insulin resistance due to bariatric sur- gery may influence the adrenal gland’s effect on steroid hormone production. In the study by Sarwer et al., DHEA- S levels significantly decreased by the end of the second year after bariatric surgery, but no significant difference was noted at the end of the first year or between the first and sec- ond years [21]. In our study, when comparing DHEA-S with the preoperative value, we observed a significant increase in the 3rd and 6th postoperative months. This difference indi- cates that the response of DHEA-S levels to bariatric surgery may evolve over time, with potential increases in the short- term followed by decreases in the long-term. In the study by Ernst et al., a decline in DHEA-S hormone levels was noted in women who experienced significant weight losses following bariatric surgery [22]. Conversely, Ram et al. reported no change in DHEA-S plasma levels despite weight loss after laparoscopic adjustable gastric banding (LAGB) surgery [23]. The increase in DHEA-S seen in our study underscores the complexity of bariatric surgery’s effects on the hormonal system. This scenario highlights the need for long-term follow-up studies to gain a deeper understanding of hormonal changes after bariatric surgery over time. Vari- ations in patient populations across studies (e.g., age, ethnic- ity, baseline DHEA-S levels, prevalence of PCOS, etc.) may contribute to differences in hormonal responses. Bhandari et al. found that bariatric surgery was highly effective in eliminating hirsutism in obese women with PCOS [21]. In the majority of patients (74.6%), hirsutism was completely resolved within 6 months, with significant improvements observed over the following years (follow-up period: five years) [24]. Similarly, Singh et al. investigated the effects of bariatric surgery on clinical, biochemical, and hormonal parameters in women with PCOS and reported complete resolution of hirsutism in 44% of patients (5 out of 11), with the mean hirsutism score decreasing from 11 to 9 after 1 year [16]. In our study, the 6th postoperative month observed a 43% reduction in hirsutism. Extending the follow-up period and quantifying the degree of improvement in hirsutism could further enhance the comprehensiveness of our study and provide a more robust comparison. Obesity is also associated with higher rates of dys- menorrhea, premenstrual disorders, and heavy menstrual bleeding. In a study by Pilone et al., AMH levels were found to increase following laparoscopic sleeve gastrec- tomy in obese women, and this increase was accompanied by improvements in the menstrual cycle and a reduction in dysmenorrhea [19]. Similarly, our study observed a statis- tically significant decrease in dysmenorrhea at 6 months. Obesity may contribute to chronic inflammation, which 3155Obesity Surgery (2025) 35:3149–3156 can elevate the production of molecules such as prosta- glandins that play a role in dysmenorrhea. Weight loss may help lower prostaglandin levels by reducing inflammation, potentially leading to decreased menstrual pain. This prospective observational study demonstrated that bariatric surgery leads to significant reductions in weight and body mass index in obese women, along with concur- rent decreases in androgen levels (androstenedione and total testosterone) and increases in SHBG, DHEA-S, and AMH levels. Additionally, while this study did not directly assess fertility outcomes such as conception rates or time to pregnancy, the observed improvements in key reproduc- tive parameters—specifically the reduction in hyperandro- genism (evidenced by decreased testosterone and andros- tenedione, normalization of ovarian morphology (reduced PCO appearance)—are strongly indicative of an enhanced endocrine environment conducive to improved ovulatory function and, consequently, fertility potential. Indeed, the restoration of regular ovulatory cycles and improved hormonal balance following bariatric surgery-induced weight loss are well-documented mechanisms leading to increased rates of spontaneous conception and reduced infertility in women with obesity, particularly those with PCOS [4, 5, 25]. The increase in AMH observed in our study at 6 months, alongside these other positive changes, may also reflect an improvement in the follicular environ- ment, although its direct implication for fertility outcomes requires further nuanced investigation [26]. A limitation of this study is the lack of free testosterone measurements. While we observed significant changes in total testoster- one and SHBG, the calculation of free testosterone, which requires serum albumin levels (not systematically col- lected for this purpose in our study), would have provided a more direct measure of bioavailable androgen. Future research should aim to include this parameter for a more comprehensive assessment of androgen status. A further limitation is the reliance on BMI as the pri- mary measure of obesity and weight loss, without detailed body composition analysis (e.g., fat mass, visceral adipos- ity). While BMI is a standard clinical tool, direct measures of fat mass and its distribution could offer more precise insights into the relationship between adipose tissue reduc- tion and the observed hormonal and ovarian changes, par- ticularly given the strong link between central adiposity and hyperandrogenism [27]. These findings highlight that bariatric surgery not only facilitates weight loss but also contributes to hormonal, clinical, and radiological alterations. In conclusion, bar- iatric surgery is an effective treatment option that may positively influence reproductive health by enhancing hor- monal balance in obese women. However, further compre- hensive studies are needed to evaluate its long-term effects and implications across different patient populations. Author Contribution Conception and design:Y.S., H.B., A.B. Acquisition of data:Y.S., H.B., A.B. Analysis and Interpretation of data:Y.S.,S.A., A.B., Drafting of the manuscript: Y.S., H.B.,S.A., A.B. Critical revision of the manuscript for important intellectual content: Y.S., A.B. Statistical analysis: S.A. Administrative technical or material support: A.B Supervision: A.B. Funding Open access funding provided by the Scientific and Techno- logical Research Council of Türkiye (TÜBİTAK). Data Availability No datasets were generated or analysed during the current study. Declarations Ethics Approval This prospective cohort study received approval from the Gazi University Hospital Ethics Committee (decision date: Septem- ber 21, 2020; decision number: 626). Informed consent was obtained from all patients participating in the study. Conflict of interests The authors declare that they have no competing interests. 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