AMH is produced by small antral follicles and is the most reliable circulating marker of ovarian reserve. Following total hysterectomy, the concentration of AMH may decline by 20–30%, and even more in patients with low reserve. Atabekoğlu et al. (2012) [18] reported that total hysterectomy resulted in a larger decrease in the ovarian reserve, as measured by AMH level, at 4 months after surgery. Specifically, the AMH level decreased by 30% more than in the controls. A prospective cohort study by Trabuco et al. (2016) [19] showed that hysterectomy resulted in a significant decrease of almost 20% in the AMH level at 1 year compared with the control group. The hysterectomy group also exhibited a significantly greater fall in AMH (–40.7% vs. 20.9%, p 0.001), and a higher rate of undetectability (12.8% vs. 4.7%, p 0.02). The postoperative decrease in AMH was 0.77 times greater than in the control group (p 0.001). The low reserve group (AMH $\le$1.2 ng/mL) showed a greater decline in AMH in the hysterectomy group than controls (58.3% vs. 19.1%, p 0.003), with 24.6% having undetectable postoperative AMH. In the high reserve group (AMH $>$1.2 ng/mL), the decline in AMH was not significantly different to controls (34.4% vs. –21.2%, p = 0.06), but AMH was still lower (0.81-fold, p 0.003). In a meta-analysis of 14 studies with a total of 1457 women, Huang et al. (2023) [20] found significantly lower AMH levels in the hysterectomy group than the control group, with a weighted mean difference (WMD) of –0.56 (95% CI: –0.72 to –0.39, p 0.0001).

Serum FSH levels are significantly elevated in patients after hysterectomy. Huang et al. (2023) [20] reported significantly elevated FSH levels in the hysterectomy group compared to the control group (WMD = 2.96, 95% CI: 1.47–4.44, p 0.001). Maiti et al. (2018) [21] found that 1 year after hysterectomy, patients had significantly increased serum FSH from baseline (7.5 IU/L to 12.3 IU/L), as well as a significant (p 0.05) decrease in ovarian volume and PI, suggesting decreased blood flow with atrophy. After 1 year, 20% had FSH $>$20 IU/L, indicating perimenopausal transition, while 5% had FSH $>$40 IU/L, indicating menopausal transition. Cooper and Thorp (1999) [22] reported a strong association between hysterectomy and elevated serum FSH level ($>$20 IU/L). Patients with unilateral oophorectomy had 2.4-fold higher odds of elevated FSH ($>$20 IU/L) compared to those with bilateral ovarian preservation (OR = 2.4, 95% CI: 1.3–4.6).

Inhibin B is secreted by growing follicles and negatively regulates pituitary FSH secretion, with its decline indicating a diminished follicular pool. Studies have consistently shown that inhibin B levels are significantly reduced after hysterectomy. A meta-analysis conducted by Huang et al. (2023) [20] revealed the test group showed a decrease of 14.34 pg/mL (95% CI: –24.69 to –3.99, p 0.001) in the level of inhibin B, aligning with changes in AMH and indicating a decline in follicular reserve. Tapisiz et al. (2008) [16] also found that inhibin B was significantly lower in the hysterectomized group than in the control group (p = 0.007), reflecting diminished ovarian feedback inhibition, as demonstrated by experiments in rats. A randomized controlled trial by Halmesmäki et al. (2007) [4] involving 107 participants found that serum inhibin B levels were significantly decreased (p 0.05), with hysterectomy emerging as an independent predictor (p = 0.05) in multivariate regression analysis. Nahás et al. (2003) [23] conducted a prospective case-control study with 61 participants in the hysterectomy group and 30 in the control group. They found a significant decline in serum inhibin B levels post-TAH, with median inhibin B levels decreasing notably at 6 and 12 months (p 0.05). Some patients experienced biochemical failure, defined as FSH $>$40 mIU/mL and E2 20 pg/mL. Post-surgery, a percentage of patients exhibited FSH $>$40 mIU/mL, E2 20 pg/mL, and inhibin B 5 pg/mL at the 12-month mark.

Most studies have shown that simultaneous removal of the fallopian tubes during hysterectomy (opportunistic salpingectomy (OS) or prophylactic bilateral salpingectomy (PBS)) does not cause significant acute damage to ovarian reserve markers (e.g., AMH, FSH, LH). Behnamfar and Jabbari (2017) [31] compared combined BSO in hysterectomy with tubal preservation group, finding significantly higher FSH and LH (p 0.001), but no difference between groups (FSH: p = 0.17; LH: p = 0.16). A retrospective cohort study (n = 79) by Chen et al. (2022) [32] found that hysterectomy with OS significantly reduced the time to menopause (1.84 vs. 2.93 years, p = 0.031; p = 0.029 after adjusting for covariates). The OS group also had higher body mass index (BMI) (25.27 vs. 22.97 kg/m², p = 0.01) and sleep disturbances (41% vs. 12%, p = 0.01). Tehranian et al. (2017) [33] conducted a randomized controlled trial on the effect of simultaneous salpingo-oophorectomy during hysterectomy on ovarian reserve (n = 30). All patients showed a significant postoperative decrease in AMH (1.32 $\pm$ 0.91 to 1.05 $\pm$ 0.88 ng/mL, p 0.001), but no significant difference was found in the rate of decrease in AMH between the two groups (25% in salpingo-oophorectomy group vs. 26% in the control group, p = 0.23). A systematic review and meta-analysis of 9 studies by Gelderblom et al. (2022) [34]found that OS at the end of pregnancy did not affect ovarian reserve markers. In particular, there was no significant decrease in AMH at 3 months after salpingectomy (p = 0.21). Van Lieshout et al. (2018) [35] conducted a Cochrane systematic review and found that combined OS during hysterectomy did not significantly increase the surgical risk or impair ovarian function. A prospective cohort study (n = 60) by Naaman et al. (2017) [36] found that hysterectomy with bilateral salpingectomy or fimbriectomy did not significantly affect ovarian reserve, as evidenced by changes in AMH (+0.53 vs. –0.02 ng/mL, p = 0.25), FSH (–2.53 vs. –7.20 IU/L, p = 0.30), and Doppler ultrasound parameters (all p $>$ 0.05). A recent multicenter randomized controlled trial (n = 104) by Van Lieshout et al. (2019) [37] found that hysterectomy with opportunistic bilateral salpingectomy did not significantly impact ovarian reserve compared to standard hysterectomy. The study reported a non-significant difference in AMH levels between the two groups (change in AMH: –0.14 vs. 0.00 pmol/L, p = 0.49). A prospective observational study (n = 71) conducted by Venturella et al. (2017) [38] found that PBS in total laparoscopic hysterectomy (TLH) did not affect the long-term ovarian reserve 3 years postoperatively (OvAge vs. chronological age: 49.22 $\pm$ 2.57 vs. 49.61 $\pm$ 2.15 years, p = 0.900). The OvAge® model for AMH (0.12 $\pm$ 0.20 ng/mL), FSH (44.30 $\pm$ 219.92 mU/mL) and 3D-AFC (1.91 $\pm$ 1.28) showed equivalent slopes in the PBS and control groups (r = 1.0008, p = 0.001).

The prospective cohort study (n = 67 patients) by Yuan et al. (2015) [39] revealed that TLH caused a greater decline in serum AMH levels than LSH at 4 months post-surgery (p = 0.017).

Women with bilateral ovarian preservation show a significantly higher 5-year rate of normal ovarian function than those with unilateral preservation (89% vs. 66%). Intraoperative preservation of both ovaries is therefore recommended as a priority. For women requiring unilateral ovarian removal, postoperative monitoring of AMH should be performed every 6 months for early detection of functional decline. A prospective randomized study by Bukovsky et al. (1995) [40] found that abdominal hysterectomy with unilateral oophorectomy (USO) resulted in a higher dysfunction rate (35% vs. 10%, p = 0.02) at the 6-month follow-up assessment compared to ovarian conservation. A prospective cohort study by Farquhar et al. (2005) [13] involving 257 women in the hysterectomy group and 259 controls found the 5-year menopausal rate was significantly higher in women who retained one ovary (35.7%, 10/28) compared to those retaining both ovaries (16.9%, p 0.01). A prospective cohort study by Moorman et al. (2011) [14] involving 406 individuals in the hysterectomy group and 465 controls found that USO was associated with a higher risk (HR = 2.93) compared to women who retained bilateral ovaries (HR = 1.74).

Laparoscopic hysterectomy has been associated with substantial short-term impacts on ovarian reserve function, possibly due to the thermal effects of electrocoagulation during the procedure. In contrast, open surgical approaches or techniques that preserve the ovarian blood supply may offer superior protection of ovarian function. A prospective cohort study by Chun and Ji (2020) [41] examined the impact of hysterectomy with ovarian preservation on ovarian reserve in 86 premenopausal women aged 31–48 years. The results showed differential effects during the early postoperative period depending on the surgical approach. While the laparoscopic group experienced a greater reduction in AMH level (0.42 ng/mL) compared to the open group (0.01 ng/mL), this did not reach statistical significance (p = 0.053). Cho et al. (2017) [42] prospectively monitored the AMH level in 91 individuals and found no significant difference in the rate of decline between TLH and non-TLH groups at 6 months postoperatively (TLH 42.1% vs. non-TLH 33.3%, p = 0.545). However, the TLH group exhibited a sustained decrease in the mean AMH value (3.5 to 1.6 ng/mL), whereas the AMH level remained relatively stable in the non-TLH group (2.4 to 2.6 ng/mL). The systematic review and meta-analysis of 9 studies by Gelderblom et al. (2022) [34] found a significant decline of more than 40% in the AMH level at 2 months postoperatively in the TLH group (p = 0.042), compared to a 20% decline in the non-TLH group. This difference may be attributable to thermal damage from the electrocoagulation equipment used in laparoscopic procedures, which can adversely impact ovarian tissues or blood vessels through heat diffusion. A randomized controlled trial (n = 100) conducted by Cai et al. (2017) [43] compared traditional hysterectomy with a novel hysterectomy technique that preserves the uterine blood supply (STHMUV, uterine blood supply-preserving hysterectomy technique). Superior ovarian protection was observed with the STHMUV technique, which maintained stable postoperative estradiol (E2) levels (346.12 pg/mL to 298.34 pg/mL) over 2 years (p $>$ 0.05). In contrast, traditional hysterectomy exhibited a significant decline in E2 (343.24 pg/mL to 203.17 pg/mL, p 0.05), and significantly lower E2 levels compared to STHMUV. Furthermore, the STHMUV group showed a significantly smaller increase in FSH (17.65 U/L to 20.17 U/L) compared to the traditional hysterectomy group (16.32 U/L to 89.01 U/L, p 0.05).

Younger patients (40 years) have a higher risk of postoperative ovarian failure and a stronger association with surgery. Older patients ($\ge$40 years) also have a significantly higher risk of ovarian failure (HR = 1.79) after hysterectomy. However, their risk is lower than for the younger group, probably because their ovarian reserve is already in decline approaching the age of natural menopause, and hence the ‘extra blow’ of surgery is relatively limited. Huang et al. (2023) [20] conducted a systematic review and meta-analysis of 14 studies with 1457 premenopausal women. Their analysis revealed that women aged $>$40 years exhibited greater increases in FSH and LH levels, and more significant decreases in E2 concentrations, compared to their younger counterparts. However, the reduction in AMH did not show any significant age-related effects, whereas some studies have suggested the decline in AMH levels following hysterectomy is more pronounced in younger patients. For instance, a study by Yuan et al. (2019) [44] involving 84 participants found a stronger negative correlation between hysterectomy and AMH levels in patients aged 40 years (r = –0.48 at 6 weeks, p 0.001). Additionally, a prospective cohort study by Moorman et al. (2011) [14] involving 406 hysterectomy patients and 465 controls reported a stronger association between hysterectomy and ovarian failure in women aged 40 years (HR = 4.29, 95% CI: 0.83–22.3). While the risk of ovarian failure was also significantly elevated in the $\ge$40 years group, the magnitude was lower (HR = 1.79, 95% CI: 1.18–2.71), likely due to the wider confidence intervals resulting from a limited sample size.

Cooper and Thorp (1999) [22] reported the impact of hysterectomy on FSH levels (OR = 1.5) was less pronounced than that of smoking (OR = 2.0), but significantly greater than the natural aging process. This finding underscores the importance of incorporating the effect of hysterectomy on the FSH level into postoperative management strategies.

In the absence of clear ovarian pathology, bilateral preservation is favored (89% vs. 66% for unilateral preservation 5 years postoperatively) [13]. Patients undergoing unilateral oophorectomy should be informed of the 2–3-fold increased risk of postoperative POI (HR = 2.93) [14].

Opportunistic Salpingectomy (OS) does not cause significant acute damage to ovarian function, but may shorten the time to menopause (1.84 years in the OS group vs. 2.93 years in the preserved group) [32, 34], and should thus be considered in the context of the patient’s age and reproductive needs. When tubal resection is required, fine dissection should be used to avoid damage to the ovarian mesosalpinx vessels. AMH is monitored postoperatively until it stabilizes, usually after 3–6 months.

In benign conditions, extrafascial subtotal resection is favored over radical resection to minimize the decrease in AMH level (p = 0.001) and to maintain the ovarian blood supply provided by the uterine artery, which normally contributes 50–70% of the total supply [34].

Careful use of electrocoagulation equipment is required, with preference given to cold knife separation or low-power modes of energy instrumentation to minimize ovarian damage from heat spread [34, 43].

Surgical techniques that preserve the uterine vasculature, such as the STHMUV procedure, are recommended to maintain postoperative estrogen homeostasis. These modified approaches result in a less pronounced decrease in estradiol levels (15%) compared to conventional methods ($>$40%), which is a desirable outcome [43].