Aim: To compare the rate of ovarian hyperstimulation syndrome in women with and without polycystic ovarian syndrome, and to determine the cut-off for the antral follicle count and the anti-Müllerian hormone level predictive of ovarian hyperstimulation syndrome in both groups. Methods: This was a prospective cohort study conducted in women aged 20–35 years who were undergoing controlled ovarian stimulation. The women were divided into those with polycystic ovarian syndrome and the controls on the basis of the Rotterdam criteria. The outcome of stimulation was recorded, and the ovarian response markers were compared in both groups. Results: Among 689 women included in the study, 276 (40.1%) had polycystic ovarian syndrome, and 476 (59.9%) were used as the controls. Ovarian hyperstimulation syndrome occurred in 19.6% of the cases, and in 7.7% of the controls (p <0.001). The conception rate was greater in the group of cases (52.5% vs. 16.5%, p = 0.001). Among the cases, the sensitivity and specificity for the prediction of hyper-response were 94.4% and 97.3% for AFC, and 92.6% and 93.7% for the anti-Müllerian hormone, at the cut-off values of ≥18 and ≥6.425 ng/ml, respectively. Among the controls, the sensitivity and specificity for the prediction of hyper-response were 93.8% and 97.1% for the antral follicle count, and 93.6% and 94.5% for the anti-Müllerian hormone, at the cut-off values of ≥10 and ≥3.95 ng/ml, respectively. Conclusion: Group-specific values should be used to identify and counsel women undergoing controlled ovarian stimulation. In light of available evidence, gynaecologists should be trained to perform ultrasound evaluation, determine the antral follicle count of their patients, and offer them appropriate counselling.

antral follicle count (AFC); polycystic ovarian syndrome (PCOS); ovarian hyperstimulation syndrome (OHSS)