Background: Ovarian hyperstimulation syndrome (OHSS), a complication of ovarian stimulation, has various adverse effects on both pregnant women and their offspring. However, whether OHSS will affect intellectual ability in offspring is still unknown. Methods: We recruited 86 Chinese children born to OHSS women and 172 children conceived with non-OHSS In Vitro Fertilization (IVF) in this cohort study. Their intellectual ability was assessed according to the Revised Chinese Version of the Wechsler Intelligence Scale for Children (C-WISC). Verbal Intelligence Quotient (VIQ), Performance Intelligence Quotient (PIQ), and Full Intelligence Quotient (FIQ) were calculated. The investigation was registered in Chinese Clinical Trial Registry (ChiCTR-SOC-16009555). Findings: OHSS offspring scored less on C-WISC (mean (standard deviation [SD]): (VIQ = 92.7 (14.7), PIQ = 108.9 (13.1), FIQ = 100.6 (13.4)) compared with non-OHSS IVF offspring (VIQ = 100.1 (13.2), PIQ = 113.7 (10.8), FIQ = 107.4 (11.5)). The prevalence of low IQ (<80) children was 4.7 times higher in OHSS offspring compared with non-OHSS offspring. Maternal estradiol level on hCG administration day was negatively associated with FIQ in offspring. Interpretation: OHSS offspring displayed reduced intellectual ability. Prenatal estradiol exposure might be involved in underlying mechanism.
