Received September 29, 2025
Accepted October 23, 2025

Background: Several risk factors including increased both antral follicle count (AFC), anti-Mullerian hormone (AMH) and serum estradiol (E2) levels increase the risk of ovarian hyperstimulation syndrome (OHSS). Methods: We studied 71 women with a median age of 32.7 years and body mass index (BMI) of 22.8 kg/m2 with moderate (n=38) and severe (n=31) OHSS. We measured E2, hemoglobin (Hb), hematocrit (Hct), creatinine, albumin (Alb), total protein (TP), D-dimer (DD), and alanine aminotransferase (ALT) levels at the day of the hospitalization and every second day until the end of hospitalization. Data regarding the length of the hospitalization along with pregnancy outcome were recorded Results: There were no intergroup differences among women with moderate and severe OHSS regarding the age, BMI and the length of hospitalization between the two studied groups. The total pregnancy rate in both moderate and severe OHSS was 61.4% (n=27), however, in women with severe OHSS positive pregnancy outcome was 2-times lower and accompanied by longer hospitalization (2.9-times) when compared with the moderate OHSS group. All women with OHSS had elevated initial E2 levels (>6910 pg/mL). Women with severe OHSS had higher initial E2 and Hct levels along with lower Alb and TP concentrations in contrast to moderate OHSS. Conclusion: Elevated estradiol concentration is an independent risk factor for OHSS in women undergoing COH. Basal serum albumin concentration along with total protein level and hematocrit are predictive factors for OHSS severity.