BACKGROUND: Infertility affects many reproductive-aged couples, with assisted reproductive technology (ART) offering hope but also significant emotional stress due to invasive procedures, hormonal fluctuations, uncertainty, and financial and emotional burden of repeated cycles. Ovarian hyperstimulation syndrome (OHSS), a common ART complication, may further aggravate psychological distress, yet its mental health impact remains understudied. METHODS: This longitudinal study included 1,429 women undergoing their first ART cycle at a reproductive center in China. Psychological assessments were conducted at four critical time points: before ART, post-surgery (early pregnancy), mid-pregnancy and late pregnancy. Validated scales (SAS, CES-D, CPSS, PSQI) measured anxiety, depression, stress, and sleep quality. OHSS was diagnosed per clinical guidelines. Generalized estimating equations (GEEs) assessed changes over time and the moderating effects of OHSS, adjusting for age, education level and income. RESULTS: OHSS occurred in 9.2% of participants, who tended to be younger and have higher socioeconomic status. Anxiety peaked after surgery and remained elevated
stress declined steadily
sleep quality improved
depression rebounded slightly in late pregnancy. OHSS significantly intensified anxiety and stress but had no clear impact on depression or sleep. CONCLUSIONS: Emotional responses during ART are dynamic. OHSS amplifies anxiety and stress, warranting integrated psychological support within ART programs, particularly for OHSS-affected women.