Polycystic ovary syndrome and excessive body weight impact independently and synergically on fertility treatment outcomes.

The data analysis yielded significant differences in hormone profiles (Table  1 , Table S1 ) and IVF outcomes (Table  2 , Table S2 ) across the different groups of women undergoing IVF. Women classified as having overweight or obesity demonstrated a significantly higher BMI compared to their normal-weight counterparts ( p  < 0.0001). However, no significant differences were found between the normal-weight groups (with or without PCOS) or between the overweight/obesity groups. Specifically, the BMI difference between the overweight/obesity control group (28.35 ± 3.05 kg/m²), classified as overweight, and the PCOS overweight/obesity subgroup (31.67 ± 5.03 kg/m²), classified as obesity, was not statistically significant ( p  = 0.8589). None of the participants were under obesity management drugs or metformin at the time of study enrollment. Comparative analysis revealed that both overweight/obesity and PCOS groups had distinctive hormone profiles compared to controls, highlighting condition specific and body weight related biomarkers. Women in the PCOS groups exhibited significantly higher baseline LH levels compared to both control groups. Specifically, the normal-weight PCOS group had markedly elevated LH levels relative to normal-weight controls (11.72 ± 5.99 mIU/mL vs. 5.72 ± 1.57 mIU/mL, p  < 0.0001) and overweight/obesity controls (5.25 ± 2.06 mIU/mL, p <  0.0001). However, no significant differences in LH levels were observed between the PCOS groups. Baseline FSH levels were significantly lower in both PCOS groups compared to normal-weight controls, while no significant difference was found between the PCOS groups. Consequently, both PCOS groups exhibited significantly higher LH: FSH ratios compared to controls. AMH levels were also significantly higher in both PCOS groups, but no significant differences were detected between the PCOS groups. Baseline E 2 levels were lower in overweight/obesity controls when compared to normal-weight controls (38.00 ± 13.44 pg/mL vs. 63.06 ± 27.23 pg/mL, p  < 0.01). Similarly, E 2 levels were lower in the overweight/obesity PCOS group when compared to normal-weight PCOS group. A profile that was reversed on the trigger day with both PCOS groups depicting significantly higher E 2 levels compared to the groups without PCOS. In contrast, progesterone levels on the trigger day, were found to be significantly higher in the normal-weight PCOS group when compared both to the normal-weight and overweight/obesity control groups (1401 ± 927 ng/mL vs. normal-weight control: 770 ± 541 ng/mL, p  < 0.01; vs. overweight/obesity control: 780 ± 554 ng/mL, p  < 0.05). On the day of oocyte retrieval, total testosterone plasma levels were significantly higher in the overweight/obesity PCOS group compared to all other study groups, including the normal-weight PCOS and both control groups (overweight/obesity PCOS: 2.24 ± 1.51 ng/mL vs. normal-weight control: 1.10 ± 0.31 ng/mL, p  < 0.0001; vs. overweight/obesity control: 1.24 ± 0.47 ng/mL, p  < 0.05; vs. normal-weight PCOS: 1.25 ± 0.43 ng/mL, p  < 0.01). A similar profile was observed for ∆4-androstenedione, with significantly higher levels in the overweight/obesity PCOS group compared to both control groups (5.54 ± 3.68 ng/mL vs. normal-weight control: 3.05 ± 1.04 ng/mL, p  < 0.001; vs. overweight/obesity control: 2.96 ± 0.99 ng/mL, p  < 0.01). On the day of oocyte retrieval, distinctive FF hormone signatures were also identified that differentiate the groups. Namely, total testosterone levels were significantly higher in the overweight/obesity PCOS group as compared to the normal-weight control group (15.56 ± 14.27 ng/mL vs. 5.80 ± 3.23 ng/mL, p  < 0.001); as well as, ∆4-androstenedione levels, which were significantly higher in the overweight/obesity PCOS group compared to the normal-weight control group (31.04 ± 50.01 ng/mL vs. 6.03 ± 2.67 ng/mL, p  < 0.01). Noticeably, FF SHBG levels were significantly lower in both overweight/obesity groups when compared to the normal-weight PCOS group (overweight/obesity control: 139.70 ± 81.87 nmol/L vs. normal-weight PCOS: 199.30 ± 94.60 nmol/L, p  < 0.05; overweight/obesity PCOS: 138.50 ± 80.00 nmol/L vs. normal-weight PCOS: 199.30 ± 94.60 nmol/L, p  < 0.05). FF progesterone levels were significantly lower in both PCOS groups as compared to controls, suggesting impaired follicular function. Normal-weight women with PCOS exhibited significantly lower FF progesterone levels compared to normal-weight controls (11819 ± 5277 ng/mL vs. 18878 ± 8169 ng/mL, p  < 0.01). This difference was even more pronounced in the overweight/obesity PCOS group, as FF progesterone levels were even lower than observed in both control groups (8.868 ± 3.709 ng/mL vs. normal-weight control: 18.878 ± 8.169 ng/mL, p  < 0.0001; vs. overweight/obesity control: 16.871 ± 8.132 ng/mL, p  < 0.0001). No significant differences in FF E 2 levels were observed between the groups. Despite fasting glucose levels did not differ significantly between the study groups, insulin levels and HOMA-IR were significantly higher in overweight/obesity controls and overweight/obesity PCOS groups, suggesting altered insulin secretion and increased insulin resistance. Insulin levels were higher in the overweight/obesity control group (11.02 ± 7.82 µIU/mL) compared to the normal-weight control group (6.04 ± 2.65 µIU/mL, p  < 0.05) and the normal-weight PCOS group (5.64 ± 3.87 µIU/mL, p  < 0.01). Similarly, the overweight/obesity PCOS group also had higher insulin levels (12.97 ± 5.85 µIU/mL) than the normal-weight control group ( p  < 0.001) and the normal-weight PCOS group ( p  < 0.0001). Insulin resistance, as assessed by the HOMA-IR, was greater in the overweight/obesity control group compared to the normal-weight control group, although it only differed significantly from the normal-weight PCOS group (2.60 ± 1.91 vs. 1.26 ± 1.08, p  < 0.05). In contrast, the overweight/obesity PCOS group showed significantly higher HOMA-IR values compared to both normal-weight groups (3.00 ± 1.37 vs. normal-weight control: 1.29 ± 0.62, p  < 0.001; vs. normal-weight PCOS: 1.26 ± 1.08, p  < 0.001), indicating a more substantial alteration in this group. Table 1 Hormone profiles of women with normal-weight or overweight/obesity with and without concomitant PCOS Control Normal-weight ( n  = 33) Control Overweight/ obesity ( n  = 28) PCOS Normal-weight ( n  = 31) PCOS Overweight/ obesity ( n  = 37) p -value Age (years) 34.03 ± 4.30 33.43 ± 4.10 32.26 ± 3.83 32.16 ± 4.05 NS BMI (kg/m 2 ) 21.70 ± 1.85 28.35 ± 3.05 a 21.92 ± 1.95 d 31.67 ± 5.03 c, f a p <0.0001 c p <0.0001 d p <0.0001 f p <0.0001 Baseline hormone levels E 2 (pg/mL) 63.06 ± 27.23 38.00 ± 13.44 a 61.54 ± 35.75 d 41.27 ± 25.28 c, f a p <0.01 c p <0.001 d p <0.05 f p <0.05 LH (mIU/mL) 5.72 ± 1.57 5.25 ± 2.06 11.72 ± 5.99 b, d 8.84 ± 4.48 c, e b p <0.0001 c p <0.05 d p <0.0001 e p <0.01 FSH (mIU/mL) 8.00 ± 2.43 6.90 ± 1.80 6.62 ± 1.45 b 6.10 ± 1.48 c b p <0.05 c p <0.001 LH: FSH ratio 0.76 ± 0.23 0.76 ± 0.27 1.87 ± 1.13 b, d 1.48 ± 0.77 c, e b p <0.0001 c p <0.0001 d p <0.0001 e p <0.0001 AMH (pmol/L) 16.13 ± 6.45 16.80 ± 7.30 53.88 ± 36.59 b, d 60.16 ± 36.66 c, e b p <0.0001 c p <0.0001 d p <0.0001 e p <0.0001 Trigger day E 2 (pg/mL) 1969 ± 999 2419 ± 1507 4743 ± 5307 b, d 4819 ± 3737 c, e b p <0.01 c p <0.001 d p <0.05 e p <0.05 Progesterone (ng/mL) 770 ± 541 780 ± 554 1401 ± 927 b, d 1539 ± 2317 b p <0.01 d p <0.05 Oocyte retrieval day - Plasma levels ∆4-androstenedione (ng/mL) 3.05 ± 1.04 2.96 ± 0.99 3.73 ± 1.29 5.54 ± 3.68 c, e c p <0.001 e p <0.01 Testosterone (ng/mL) 1.10 ± 0.31 1.24 ± 0.47 1.25 ± 0.43 2.24 ± 1.51 c, e,f c p <0.0001 e p <0.05 f p <0.01 SHBG (nmol/L) 206.40 ± 84.95 147.20 ± 40.60 181.80 ± 68.54 164.30 ± 74.86 NS FAI (%) 2.09 ± 0.89 3.21 ± 1.64 2.88 ± 1.98 5.43 ± 3.53 c, f c p <0.0001 f p <0.01 Glucose (mg/dL) 86.44 ± 8.13 87.29 ± 10.12 85.70 ± 14.00 91.04 ± 11.73 NS Insulin (µIU/mL) 6.04 ± 2.65 11.02 ± 7.82 a 5.64 ± 3.87 d 12.97 ± 5.85 c, f a p <0.05 c p <0.0001 d p <0.01 f p <0.0001 HOMA-IR 1.29 ± 0.62 2.60 ± 1.91 1.26 ± 1.08 d 3.00 ± 1.37 c, f c p <0.001 d p <0.05 f p <0.0001 Oocyte retrieval day– Follicular fluid levels ∆4-androstenedione (ng/mL) 6.03 ± 2.67 8.23 ± 3.95 22.54 ± 38.26 31.04 ± 50.01 c c p <0.01 Testosterone (ng/mL) 5.80 ± 3.23 7.69 ± 3.35 10.31 ± 10.43 15.56 ± 14.27 c c p <0.001 SHBG (nmol/L) 189.70 ± 87.23 139.70 ± 81.87 199.30 ± 94.60 d 138.50 ± 80.00 f d p <0.05 f p <0.05 Progesterone (ng/mL) 18,878 ± 8169 16,871 ± 8132 11,819 ± 5277 b, 8868 ± 3709 c, e b p <0.01 c p <0.0001 e p <0.0001 E 2 (pg/mL) 439,845 ± 337,370 467,200 ± 224,058 444,871 ± 292,753 509,150 ± 319,269 NS Values are presented as mean ± standard deviation. p -value < 0.05 was considered statistically significant. AMH: anti-Müllerian hormone; BMI: body mass index; E 2 : estradiol; FAI: free androgen index; FSH: follicle-stimulating hormone; HOMA-IR: Homeostatic Model Assessment for Insulin Resistance; IVF: in vitro fertilization; IU: international units; LH: luteinizing hormone; NS: no significance; PCOS: polycystic ovary syndrome; SHBG: sex hormone binding globulin. a control normal weight compared with control overweight/obesity; b control normal weight compared with PCOS normal weight; c control normal weight compared with PCOS overweight/obesity; d control overweight/obesity compared with PCOS normal weight; e control overweight/obesity compared with PCOS overweight/obesity; f PCOS normal weight compared with PCOS overweight/obesity Hormone profiles of women with normal-weight or overweight/obesity with and without concomitant PCOS a p <0.0001 c p <0.0001 d p <0.0001 f p <0.0001 a p <0.01 c p <0.001 d p <0.05 f p <0.05 b p <0.0001 c p <0.05 d p <0.0001 e p <0.01 b p <0.05 c p <0.001 b p <0.0001 c p <0.0001 d p <0.0001 e p <0.0001 b p <0.0001 c p <0.0001 d p <0.0001 e p <0.0001 b p <0.01 c p <0.001 d p <0.05 e p <0.05 b p <0.01 d p <0.05 c p <0.001 e p <0.01 c p <0.0001 e p <0.05 f p <0.01 c p <0.0001 f p <0.01 a p <0.05 c p <0.0001 d p <0.01 f p <0.0001 c p <0.001 d p <0.05 f p <0.0001 d p <0.05 f p <0.05 b p <0.01 c p <0.0001 e p <0.0001 Values are presented as mean ± standard deviation. p -value < 0.05 was considered statistically significant. AMH: anti-Müllerian hormone; BMI: body mass index; E 2 : estradiol; FAI: free androgen index; FSH: follicle-stimulating hormone; HOMA-IR: Homeostatic Model Assessment for Insulin Resistance; IVF: in vitro fertilization; IU: international units; LH: luteinizing hormone; NS: no significance; PCOS: polycystic ovary syndrome; SHBG: sex hormone binding globulin. a control normal weight compared with control overweight/obesity; b control normal weight compared with PCOS normal weight; c control normal weight compared with PCOS overweight/obesity; d control overweight/obesity compared with PCOS normal weight; e control overweight/obesity compared with PCOS overweight/obesity; f PCOS normal weight compared with PCOS overweight/obesity Women with PCOS exhibited significant differences in IVF cycle parameters when compared to controls. The most striking difference was the fact that normal-weight women with PCOS required a significantly lower gonadotropins dosage for ovarian stimulation compared to all other study groups, including the normal-weight control group (1981 ± 411 IU vs. 2641 ± 652 IU, p  < 0.0001), the overweight/obesity control group (1981 ± 411 IU vs. 2646 ± 650 IU, p  < 0.001), and the overweight/obesity PCOS group (1981 ± 411 IU vs. 2503 ± 611 IU, p  < 0.01). Additionally, the normal-weight women with PCOS required a shorter stimulation period than the women with overweight/obesity and PCOS (10 ± 1 days vs. 11 ± 2 days, p  < 0.01). Furthermore, ovarian stimulation in PCOS groups resulted in a significantly higher number of Cumulus-Oocyte Complexes (COCs) compared to the control groups. Specifically, the normal-weight PCOS group had a significantly higher number of COCs than both the normal-weight control group (19 ± 8 vs. 8 ± 3, p  < 0.0001) and the overweight/obesity control group (19 ± 8 vs. 10 ± 5, p  < 0.001). Similarly, the overweight/obesity PCOS group also had significantly more COCs than the normal-weight control group (16 ± 9 vs. 8 ± 3, p  < 0.0001) and the overweight/obesity control group (16 ± 9 vs. 10 ± 5, p  < 0.01). Notably, the normal-weight PCOS group also had a higher number of two-pronucleated oocytes compared to the normal-weight control group (9 ± 7 vs. 4 ± 2, p  < 0.01) and the overweight/obesity control group (9 ± 7 vs. 5 ± 3, p  < 0.05), although a lower cleavage rate compared to the normal-weight control group (97.33 ± 6.23 vs. 100 ± 0.0, p  < 0.05). Despite women with PCOS presenting numerical superiority in several IVF parameters, no differences in oocyte immaturity, fertilization and blastocyst rate were observed (Table  2 , Table S2 ). Table 2 Comparison IVF cycle characteristics in women with normal-weight or overweight/obesity with and without concomitant PCOS Control Normal-weight ( n  = 33) Control Overweight/obesity ( n  = 28) PCOS Normal-weight ( n  = 31) PCOS Overweight/obesity ( n  = 37) p -value Total Gonadotropins dose, IU 2641 ± 652 2646 ± 650 1981 ± 411 b, d 2503 ± 611 f b p <0.0001 d p <0.001 f p <0.01 No. of stimulation days 10 ± 2 11 ± 2 10 ± 1 11 ± 2 f f p <0.01 No. of COCs 8 ± 3 10 ± 5 19 ± 8 b, d 16 ± 9 c, e b p <0.0001 c p <0.001 d p <0.0001 e p <0.01 Oocyte immaturity rate (%) 14.82 ± 13.74 13.36 ± 15.07 13.52 ± 15.19 14.14 ± 12.40 NS No. of two pronucleated oocytes 4 ± 2 5 ± 3 9 ± 7 b, d 7 ± 5 b p <0.01 d p <0.05 Fertilization rate (%) 56.68 ± 24.97 55.99 ± 28.34 56.90 ± 26.20 58.18 ± 25.19 NS Cleavage rate (%) 100 ± 0.0 97.95 ± 7.37 97.33 ± 6.23 b 98.56 ± 5.85 b p <0.05 Blastocyst rate (%) 14.82 ± 13.74 13.36 ± 15.07 13.52 ± 15.19 14.14 ± 12.40 NS Values are presented as mean ± standard deviation. p -value < 0.05 was considered statistically significant. COCs: cumulus-oocyte complexes; IVF: in vitro fertilization; IU: international units; NS: no significance; PCOS: polycystic ovary syndrome. a control normal weight compared with control overweight/obesity; b control normal weight compared with PCOS normal weight; c control normal weight compared with PCOS overweight/obesity; d control overweight/obesity compared with PCOS normal weight; e control overweight/obesity compared with PCOS overweight/obesity; f PCOS normal weight compared with PCOS overweight/obesity. Comparison IVF cycle characteristics in women with normal-weight or overweight/obesity with and without concomitant PCOS b p <0.0001 d p <0.001 f p <0.01 b p <0.0001 c p <0.001 d p <0.0001 e p <0.01 b p <0.01 d p <0.05 Values are presented as mean ± standard deviation. p -value < 0.05 was considered statistically significant. COCs: cumulus-oocyte complexes; IVF: in vitro fertilization; IU: international units; NS: no significance; PCOS: polycystic ovary syndrome. a control normal weight compared with control overweight/obesity; b control normal weight compared with PCOS normal weight; c control normal weight compared with PCOS overweight/obesity; d control overweight/obesity compared with PCOS normal weight; e control overweight/obesity compared with PCOS overweight/obesity; f PCOS normal weight compared with PCOS overweight/obesity. The linear regression analysis provided further insights into the drivers of differences in molecular profiles between normal-weight controls and overweight/obesity controls, and PCOS subgroups (Table  3 ). The coefficient B represents the magnitude of difference in each parameter compared to the reference group (normal-weight controls), along with Wald confidence intervals (95%) to determine statistical significance. For baseline E₂ levels, both overweight/obesity controls and overweight/obesity PCOS group exhibited significantly lower levels compared to normal-weight controls. Overweight/obesity controls had an E₂ level that was, on average, 25.06 pg/mL lower than normal-weight control group ( p  = 0.002). Similarly, the overweight/obesity PCOS group had E₂ levels that were 21.79 pg/mL lower than those of normal-weight controls ( p  = 0.001). These findings suggest that excess body weight, independent of PCOS status, is associated with lower baseline E 2 levels. In contrast, AMH levels were significantly higher in both PCOS groups. Normal-weight PCOS had AMH levels that were, on average, 37.75 ng/mL higher than those of normal-weight controls ( p  < 0.001), while in the overweight/obesity PCOS group, AMH levels where on average 42.30 ng/mL higher ( p  < 0.001). These results align with the well-established association between PCOS and AMH [ 16 ], although suggesting that this profile could be further exacerbated in the presence of overweight/obesity. LH levels were also significantly elevated in both PCOS groups. Normal-weight PCOS individuals exhibited LH levels that were, on average, 6.00 mIU/mL higher than those observed in normal-weight controls ( p  < 0.001). Overweight/obesity PCOS group also had higher LH levels, though to a lesser extent, with an average increase of 3.12 mIU/mL ( p  = 0.002). This pattern is consistent with the characteristic hormone profile of PCOS [ 17 ]. The more pronounced elevation in normal-weight PCOS further suggests that its expression could be modulated by body weight. Conversely, FSH levels were significantly lower in both overweight/obesity controls and PCOS groups compared to normal-weight controls. Overweight/obesity controls had FSH levels that were, on average, 1.11 mIU/mL lower than those of normal-weight controls ( p  = 0.026). Similarly, the normal-weight PCOS group exhibited FSH levels that were on average 1.39 mIU/mL lower ( p  = 0.003), while the overweight/obesity PCOS group showed even lower FSH levels, which were on average 1.91 mIU/mL lower ( p  < 0.001). These findings suggest that both obesity and PCOS are linked to disrupted FSH regulation, which may contribute to impaired follicular development. The LH: FSH ratio, a key biomarker for PCOS, was significantly elevated in both PCOS groups. In the normal-weight PCOS group the ratio was 1.12 higher ( p  < 0.001), while the overweight/obesity PCOS group exhibited a 0.73 greater ratio ( p  < 0.001), supporting the disrupted gonadotropin secretion characteristic of the syndrome [ 18 ]. In FF, androgens were markedly elevated in both PCOS groups. FF androstenedione levels were significantly higher in normal-weight PCOS, on average 16.51 ng/mL higher compared to normal-weight controls ( p  = 0.048). Overweight/obesity PCOS group showed an even greater elevation, with FF androstenedione levels on average 25.01 ng/mL higher than those of normal-weight controls ( p  = 0.002). Similarly, FF testosterone was significantly higher in the overweight/obesity PCOS group, on average 9.76 ng/mL higher compared to normal-weight controls ( p  < 0.001). These results indicate a hyperandrogenic follicular environment in PCOS [ 19 ], which appears to be exacerbated in the presence of excessive body weight. For plasma androstenedione, the overweight/obesity PCOS group exhibited significantly higher levels than normal-weight controls, on average 2.49 ng/mL higher ( p  < 0.001). This further supports the hyperandrogenic profile that characterises PCOS and most particularly in women with overweight or obesity. For SHBG, both plasma and FF levels were significantly lower in women with overweight or obesity. In plasma, overweight/obesity controls had SHBG levels that were, on average 59.21 nmol/L lower than those of normal-weight controls ( p  = 0.029). The overweight/obesity PCOS group exhibited SHBG values that were 42.12 nmol/L lower that normal-weight controls ( p  = 0.006). Similarly, FF SHBG levels were significantly lower in both overweight groups, thereby increasing free androgen availability. These findings suggest that low SHBG levels are a key signature associated with excessive body weight. For FF progesterone, both PCOS groups presented significantly lower levels compared to normal-weight controls. Normal-weight women with PCOS had on average FF progesterone that was 7059.61 ng/mL lower ( p  < 0.001), while women with overweight/obesity and PCOS exhibited an even more pronounced difference with values on average 10210.07 ng/mL lower ( p  < 0.001). These results suggest impaired follicular function in PCOS, more pronounced in the presence of overweight/obesity. For metabolic parameters, plasma fasting insulin levels were significantly higher in overweight/obesity groups. The overweight/obesity control group had insulin levels that were on average 4.99 µIU/mL higher than those of normal-weight controls ( p  = 0.001), while the overweight/obesity PCOS group exhibited an even greater average difference of 6.93 µIU/mL ( p  < 0.001). These findings reflect the counterregulatory increase of insulin secretion associated with insulin-resistance in the presence of obesity and PCOS, as confirmed by HOMA-IR. Indeed, the overweight/obesity control group had a HOMA-IR value that was, on average, 1.30 units higher than that of normal-weight control group ( p  < 0.001), while overweight/obesity PCOS group demonstrated a value that was higher by 1.71 units ( p  < 0.001). These results confirm the strong association between overweight/obesity and insulin resistance, with women with PCOS exhibiting the greatest metabolic derangement. Table 3 Comparative analysis of hormone and metabolic parameters in normal-weight, overweight/obesity, and PCOS subgroups Control Normal-weight Subgroup B CI (95%) p -value E 2 basal Control overweight/obesity -25.06 -40.07– (-10.06) 0.002 PCOS overweight/obesity -21.79 -35.65– (-7.93) 0.001 AMH PCOS normal-weight 37.75 24.28–51.21 < 0.001 PCOS overweight/obesity 42.30 29.25–55.35 < 0.001 LH PCOS normal-weight 6.00 3.89–8.10 < 0.001 PCOS overweight/obesity 3.12 1.12–5.12 0.002 FSH Control overweight/obesity -1.11 -2.08– (-0.13) 0.026 PCOS normal-weight -1.39 -2.32– (-0.46) 0.003 PCOS overweight/obesity -1.91 -2.79– (-1.02) < 0.001 LH: FSH PCOS normal-weight 1.12 0.74–1.49 < 0.001 PCOS overweight/obesity 0.73 0.37–1.09 < 0.001 FF Androstenedione PCOS normal-weight 16.51 0.11–32.91 0.048 PCOS overweight/obesity 25.01 9.3–40.71 0.002 FFSHBG Control overweight/obesity -49.96 -94.82– (-5.10) 0.029 PCOS overweight/obesity -51.16 -93.26– (-9.06) 0.017 FF Testosterone PCOS overweight/obesity 9.76 5.13–14.40 < 0.001 FF Progesterone PCOS normal-weight -7059.61 -10347.06– (-3772.16) < 0.001 PCOS overweight/obesity -10210.07 -13387.74– (-7032.41) < 0.001 P Androstenedione PCOS overweight/obesity 2.49 1.34–3.63 < 0.001 P SHBG Control overweight/obesity -59.21 -101.08– (-17.33) 0.029 PCOS overweight/obesity -42.12 -79.99– (-4.24) 0.006 P Testosterone PCOS overweight/obesity 1.14 0.68–1.60 < 0.001 P FAI PCOS overweight/obesity 3.34 2.13–4.55 < 0.001 P Insulin Control overweight/obesity 4.99 3.36–6.74 0.001 PCOS overweight/obesity 6.93 4.60–8.03 < 0.001 HOMA-IR Control overweight/obesity 1.30 0.54–2.07 < 0.001 PCOS overweight/obesity 1.71 1.02–2.41 < 0.001 Regression coefficients (B) and 95% confidence intervals (CI), p -value < 0.05 was considered statistically significant. AMH: anti-Müllerian hormone; BMI: body mass index; E 2 : estradiol; FAI: free androgen index; FF: follicular fluid: FSH: follicle-stimulating hormone; HOMA-IR: Homeostatic Model Assessment for Insulin Resistance; LH: luteinizing hormone; P: plasma; PCOS: polycystic ovary syndrome; SHBG: sex hormone binding globulin. Comparative analysis of hormone and metabolic parameters in normal-weight, overweight/obesity, and PCOS subgroups Regression coefficients (B) and 95% confidence intervals (CI), p -value < 0.05 was considered statistically significant. AMH: anti-Müllerian hormone; BMI: body mass index; E 2 : estradiol; FAI: free androgen index; FF: follicular fluid: FSH: follicle-stimulating hormone; HOMA-IR: Homeostatic Model Assessment for Insulin Resistance; LH: luteinizing hormone; P: plasma; PCOS: polycystic ovary syndrome; SHBG: sex hormone binding globulin.

A total of 129 women from couples undergoing IVF for infertility treatment at a single public academic center were recruited to participate in this study between January 2020 and February 2024. PCOS was diagnosed according to the 2003 Rotterdam criteria, in the presence of at least two of the following three characteristics: (1) oligo- and/or anovulation, (2) clinical and/or biochemical evidence of hyperandrogenism, and (3) polycystic ovaries identified via ultrasound examination, defined as having at least 12 follicles measuring 2–9 mm in diameter or an ovarian volume exceeding 10 mL [ 13 ]. The control group consisted of women with normal ovulatory function undergoing IVF due to tubal obstruction and/or male factor infertility. Exclusion criteria comprised diminished ovarian reserve as defined by the Bologna criteria [ 14 ], endometriosis, systemic diseases known to affect ovulatory function, abnormal prolactin levels, and/or thyroid dysfunction. Based on BMI and PCOS diagnosis, women were categorized into four groups: normal weight controls ( n  = 33; BMI < 25 kg/m²), overweight/obesity controls ( n  = 28; BMI ≥ 25 kg/m²), normal weight PCOS ( n  = 31; BMI < 25 kg/m²), and overweight/obesity PCOS ( n  = 37; BMI ≥ 25 kg/m²). Data was extracted from electronic medical records, encompassing age, BMI, peripheral hormone levels routinely assessed for ART, and characteristics of the IVF cycles. All participants provided written informed consent to take part in the study, which was approved by the Ethics Committee of the Institution [2020.119(097-DEFI/099-CE)]. Women underwent a Gonadotropin-Releasing Hormone (GnRH) antagonist protocol with individualized COS based on ovarian reserve testing, following standard clinical practice. In women with PCOS, a GnRH antagonist protocol in combination with GnRH agonist triggering was employed as standard practice, since this is a well-established strategy to reduce the risk of OHSS in this population [ 15 ]. Peripheral blood samples were collected via venipuncture of an antebrachial vein into EDTA-containing tubes. Hormone measurements were conducted at three distinct time points along the cycle. The first assessment was performed between the 3rd and 5th day of the menstrual cycle, up to six months before COS for IVF was initiated. In this baseline assessment, E 2 , follicle-stimulating hormone (FSH), luteinizing hormone (LH), and anti-Müllerian hormone (AMH) levels were measured. The second assessment was carried out on the trigger day after COS, to measure E 2 and progesterone levels. The third assessment took place on the day of oocyte retrieval, for glucose, insulin, ∆4-androstenedione, testosterone, and sex hormone-binding globulin (SHBG) measurements. HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) was calculated to evaluate insulin resistance. Additionally, follicular fluid (FF) was harvested for oocyte retrieval. Each follicle was individually aspirated, and the FF from multiple follicles was pooled into a single container from each study participant. The FF discarded after oocyte retrieval for IVF was used for measuring ∆4-androstenedione, testosterone, SHBG, E 2 , and progesterone levels. All plasma and FF hormone assays were performed at the routine core laboratory of the public academic tertiary hospital where the reproductive center is based. Capillary blood glucose levels were measured at the point of care using a glucometer (Freestyle Precision Neo Glucose Meter, Abbott, USA). Total testosterone, Δ4-androstenedione, progesterone, E 2 , and insulin were quantified using an electrochemiluminescence immunoassay (ECLIA, Roche Diagnostics, Mannheim, Germany), following the manufacturer’s instructions. SHBG was measured using a chemiluminescent immunometric assay (Immulite XPi instrument, Siemens Healthcare Diagnostics, UK), while AMH was assessed using an enzyme-linked immunosorbent assay (Beckman Coulter Access AMH, Immunotech, France). All statistical analyses were performed using GraphPad Prism 8.0 and IBM SPSS Statistics 29.0 software. The normality of the data distribution was assessed using the Kolmogorov-Smirnov test. If the data met the assumption of normality, one-way analysis of variance (ANOVA) was performed to compare differences among groups, followed by Tukey’s Honestly Significant Difference (HSD) test. If the normality assumption was not met, the Kruskal-Wallis test was conducted as a non-parametric alternative, followed by Dunn’s post-hoc test. Additionally, a linear regression model was applied to assess relationships between the variables. The regression analysis included the calculation of the coefficient B, along with the Wald confidence interval for the coefficient to determine the strength and significance of associations. Data are presented as mean ± standard deviation (SD) unless otherwise specified. A p -value of less than 0.05 was considered statistically significant.

Polycystic Ovary Syndrome (PCOS) is a highly prevalent endocrine disorder in women at reproductive age that is characterized by several hormone imbalances [ 1 ]. PCOS is typically associated with oligo-anovulation and hyperandrogenism, contributing to infertility [ 2 ]. Body weight is another factor that independently impacts on fertility outcomes, since women with a higher body mass index (BMI) tend to have a poor response to controlled ovarian stimulation (COS) and reduced implantation rates in assisted reproductive technology (ART) settings [ 3 ]. However, the relationship between PCOS and excessive body weight, such as overweight and obesity, seems to be complex and bidirectional [ 4 ]. Indeed, approximately 50% of the women with PCOS have overweight or obesity [ 5 ], which can precede PCOS [ 6 ] and then manifest as an obesity-related comorbidity [ 7 , 8 ]. Moreover, the symptoms of PCOS tend to be exacerbated by weight gain, and ameliorated by weight loss [ 6 ]. Nonetheless, the fact that PCOS and excessive body weigh are not invariably associated, suggests that weight-related and PCOS-specific features may differ. Therefore, although there is no doubt that both conditions can disrupt female reproductive function, the extent to which overweight or obesity contribute to PCOS manifestations is unclear. ART plays an important role in infertility treatment of women with PCOS [ 9 ]. However, the response to in vitro fertilization (IVF) can be unpredictable due to the complex interaction between hormone and metabolic factors. Additionally, when obesity is concomitantly present, the challenges associated with IVF can be even greater [ 10 , 11 ], although the reasons for this are not entirely known. Women with PCOS undergoing IVF cycles tend to have higher estradiol (E 2 ) and progesterone levels on the trigger day when compared to unaffected counterparts [ 9 ]. Elevated E 2 and progesterone levels during IVF raise concerns about ovarian hyperstimulation syndrome (OHSS) and may impair endometrial receptivity, often prompting the use of a ‘freeze-all’ strategy for safety reasons and to optimize the timing of embryo transfer [ 12 ]. These hormone shifts were also shown to correlate with BMI categories, highlighting the complex relationship between body corpulence, hormone responses, and reproductive outcomes [ 9 ]. Given this unmet need, this study aimed to clarify and distinguish the individual effects of PCOS and excess body weight on hormonal profiles and IVF outcomes, with the ultimate goal of gaining insights into how to address the reproductive challenges faced by women with PCOS undergoing infertility treatment.

This study aimed to elucidate the intricate interplay between PCOS, BMI, and reproductive outcomes among infertile women undergoing IVF. Our study findings showed significant differences in hormone profiles and IVF parameters across four different phenotypes that have critical implications for fertility management and treatment strategies in reproductive medicine. Our data revealed that women with PCOS exhibit higher LH levels, which may further contribute to disrupt normal ovarian function and exacerbate hyperandrogenism [ 20 , 21 ]. Moreover, the significantly higher LH, AMH, and androgens levels (∆4-androstenedione, testosterone, FAI) in women with PCOS were highlighted as molecular hallmarks of PCOS. As a matter of fact, AMH levels that are used as a surrogate of ovarian reserve in the general population, in women with PCOS tend to reflect the higher number of follicles rather than the fertility potential [ 22 , 23 ]. Besides, high AMH levels and LH: FSH ratio can to be useful for reinforcing/corroborating PCOS diagnosis, particularly in dubious cases [ 18 ]. In our study, women with PCOS and overweight/obesity showed not only significantly higher androgen levels, but also greater insulin resistance, depicted by higher HOMA-IR and lower SHBG levels. These findings corroborate the well-established link between obesity and insulin resistance, providing a biological basis for the metabolic disturbances that complicate reproductive outcomes in these women [ 22 , 24 ]. Furthermore, the lower SHBG levels result in higher free androgens, which aggravates the severity of hyperandrogenism [ 25 ]. In turn, androgen excess may further contribute to deteriorate glucose tolerance, although mechanistic studies are still necessary to fully elucidate on these pathways [ 26 – 29 ]. Overall, our data reinforces the previous reports by Chen-Patterson et al . (2024) who have shown that women with PCOS had different hormone profiles depending on body weight, revealing that women with normal weight exhibited elevated LH, total testosterone, and androstenedione levels, while those with obesity had lower SHBG along with higher free testosterone levels [ 30 ]. Furthermore, Si et al . (2023) also reported that women with PCOS and overweight exhibited a worse metabolic profile, with higher HOMA-IR [ 31 ]. The interplay between androgen excess and insulin resistance is particularly relevant, as substantial evidence suggests that insulin-sensitizing agents, such as metformin, may improve the ovulatory response and could be considered pre-IVF to improve reproductive outcomes [ 27 ]. All together, these findings clearly illustrate that woman with PCOS have significantly altered hormone profiles compared to unaffected counterparts, which are exacerbated in the presence of insulin resistance triggered by overweight/obesity, and ultimately influence fertility treatment outcomes. Moreover, it should be noticed that lower SHBG levels, as a surrogate for insulin resistance, were previously reported to be independently associated with a higher risk of gestational diabetes mellitus (GDM) [ 29 , 32 , 33 ]. Although our study did not assess pregnancy outcomes nor complication rates, such as GDM, these findings further support the relevance of conducting comprehensive metabolic profiling of women with overweight/obesity considering the risk of GDM. In addition, women with PCOS undergoing COS for IVF also exhibited significantly higher E 2 and progesterone levels on the trigger day when compared to unaffected counterparts. This is noteworthy, as higher E 2 levels usually reflect a more robust ovarian response and a greater likelihood of retrieving viable oocytes [ 34 ]. However, although no data on OHSS or live birth outcomes was collected for this study, higher E 2 levels also represent a risk factor for OHSS, prompting a preventive “freeze all” strategy [ 35 ]. Consequently, in order to allow time for hormone levels to normalize before embryo transfer, the decision to “freeze all” instead of transferring fresh embryos tends to be more frequent in women with PCOS [ 35 ]. Higher progesterone levels observed in women with PCOS could further complicate fresh embryo transfer, as these can impair endometrial receptivity reducing the chances of successful implantation [ 36 ]. Therefore, women with elevated progesterone levels may also benefit from a “freeze-all” approach, allowing to time embryo transfer in sync with a favorable endometrial environment at a subsequent cycle [ 37 ]. Notwithstanding, the advantages of ‘freeze-all’ strategy must be balanced against the potential risks of large-for-gestational-age infants in singleton pregnancies and pre-eclampsia in twin pregnancies [ 38 , 39 ]. During COS, normal-weight women with PCOS required a significantly lower total gonadotropins dosage compared to normal-weight controls, but not significantly different from the dosage required by overweight/obesity controls, highlighting the need for tailored stimulation protocols. Nonetheless the differences in gonadotropins requirements for COS, women with PCOS consistently depicted significantly higher number of COCs and two-pronucleated oocytes when compared to unaffected women, suggesting a potential fertility advantage. However, fertilization rates were not significantly different between the groups, while cleavage rate was notably lower in the PCOS normal-weight group compared to control normal weight. Overall, these findings suggest that women with PCOS, despite having an apparently better response to COS this does not translates into improved fertility outcomes, since the oocytes quality may be compromised, leading to suboptimal fertilization and implantation [ 18 , 19 ]. Future research focusing at addressing the impact of maternal hormone and metabolic profiles on embryo quality will be crucial to identify the determinants of IVF success among women with PCOS. While this study presents valuable insights into the interplay between BMI, hormone profiles, and fertility treatment outcomes, certain limitations merit acknowledgment. Firstly, the relatively small size of the study cohort, especially in subgroup analyses, may constrain the robustness of the findings. Secondly, the fact that no IVF clinical outcomes, such as implantation rates and live birth data were evaluated is another limitation, as these would have been crucial for understanding the impact of elevated progesterone on endometrial receptivity and overall treatment success. According Fouks et al . (2023), PCOS also has a considerable impact on cumulative live birth rate (CLBR), with normal weight women depicting a notably higher CLBR than those with obesity, who also experience significantly higher miscarriage rates and aneuploidy rates in those undergoing pre-implantation genetic testing for aneuploidy [ 40 ]. Third, the cross-sectional nature of the study hampers the possibility of conducting any causal inference. Longitudinal studies tracking changes in hormone profiles in response to weight management or different IVF protocols would be beneficial for optimizing treatment strategies tailored to women with PCOS based on their BMI. Lastly, our study is limited by the fact that no data on variables such as lifestyle habits, dietary patterns, previous use of androgen-lowering treatments, ovarian surgeries, or genetic determinants were collected nor controlled for, which could have influenced the reproductive results. Despite the limitations, this study still provides a meaningful contribution towards understanding the interaction between PCOS and obesity. Indeed, while previous studies explored the individual impact of PCOS and obesity on reproductive and hormonal profiles [ 30 ], few studies have systematically examined its independent and combined effects within the same cohort. Our study uniquely addressed this gap by analyzing four well-defined groups according to the presence of PCOS or excessive body weight and its respective controls, and by assessing both endocrine and FF markers alongside IVF outcomes. Our findings provide novel insights into PCOS and obesity interplay, particularly highlighting how obesity exacerbates not only the systemic hyperandrogenism and metabolic disturbances that can be associated with PCOS, but also at the oocyte microenvironment which is the FF, with important implications for fertility. The distinct hormone profiles associated with different BMI categories highlight the importance of explicitly incorporating overweight/obesity into the equation of management strategies [ 41 ]. By doing so, healthcare practitioners may adopt a nuanced approach of women with PCOS, particularly relevant when considering the findings of Carmina & Lobo (2022), which suggest that metabolic alterations are closely linked to BMI, irrespective of the Rotterdam classification phenotypes A, B, or C [ 42 ]. By categorizing women with PCOS within the same phenotype while disregarding corpulence can have considerable implications for fertility management as our results highlight. As such, weight management strategies—including lifestyle interventions and pharmacotherapy aimed at improving insulin sensitivity—can potentially improve the fertility outcomes of women with these particular metabolic profiles [ 27 , 28 ]. Understanding that women with PCOS, especially those with overweight or obesity, may present unique hormone profiles can guide personalized treatment approaches and potentially impact on its outcomes [ 43 , 44 ]. In summary, our findings emphasize that the intersection of BMI and PCOS significantly impacts hormone profiles and strongly advocate for incorporating BMI and metabolic assessments into routine fertility evaluations, particularly in women diagnosed with PCOS undergoing IVF.

This study highlights the significant interplay between PCOS and BMI in influencing fertility outcomes during IVF. Women with PCOS, especially those who have overweight or obesity, demonstrate distinct hormone profiles characterized by elevated LH, AMH, and androgens, along with increased insulin resistance. Incorporating BMI and metabolic assessments into routine fertility evaluations and addressing the unique needs of women with PCOS will be crucial for improving reproductive success.

Below is the link to the electronic supplementary material. Supplementary Material 1 Supplementary Material 1