Study Question: What is the prevalence of occupational stress, somatization, and burnout reported by UK and US, embryologists and the impact of work conditions on these well-being outcomes?, Summary Answer: Surveyed UK and US embryologists reported moderate perceived stress, low somatic symptom severity, high levels of burnout, and overall stressful work conditions, but with differences that could be due to country-specific occupational and employment characteristics., What Is Known Already?: Spanish, UK, US, and international surveys have identified high levels of occupational stress, somatization, burnout, and occupational health issues among embryologists. These issues have been attributed to embryologists' occupational challenges and work conditions., Study Design, Size, Duration: A cross-sectional web-based survey was sent to 253 embryologists working in UK ART/IVF clinics and 487 embryologists working in US ART/IVF clinics., Participants/materials, Setting, Methods: Participants self-reported their stress levels, somatization, burnout, and work conditions. Proportions across the Perceived Stress Scale (PSS), Patient Health Questionnaire (PHQ-15), Maslach Burnout Inventory-General Survey (MBI-GS), a single-item work unit grade (A-F), and customized occupational and sociodemographic questionnaires were calculated using descriptive statistics. Welch's t-test was utilized to compare PSS and PHQ-15 scores between groups. Risk ratios were calculated using log-binomial regression for all models except for levels of anxiety related to performing cryostorage tasks, for which Poisson models were used., Main Results and the Role of Chance: In total, 50.6% (128) of the embryologists in the UK and 50.1% (244) in the US completed the survey. Both groups self-reported moderate PSS and low PHQ-15 scores, although fewer UK embryologists scored high on the MBI cynicism dimension than their US colleagues (43% UK vs 60% US embryologists, P < 0.05). The UK and US embryologists did not differ on the MBI exhaustion dimension with both scoring high for exhaustion (59% UK vs 62% US). Although 81% and 80% of UK and US embryologists, respectively, reported working overtime, more embryologists in the UK reported being adequately compensated. Increasing levels of anxiety-related to cryostorage showed a dose-dependent increased risk of burnout on at least two MBI-GS dimensions only in the UK group, and, a dose-dependent likelihood of higher PSS and PHQ-15 scores in both groups., Limitations, Reasons for Caution: Since the two groups were surveyed 9 months apart and were self-reporting, the study is limited by the differences in responsibilities, scheduling, and workload specific to the time of year., Wider Implications of the Findings: Work-related health issues and occupational challenges shared by UK and US embryologists could be addressed by organizational enhancements and technology. Lower levels of stress and burnout among UK embryologists might be due to the HFEA-provided structure/certainty., Study Funding/competing Interest(s): This study was supported without any external funding by TMRW Life Sciences Inc., which is developing and commercializing an automated platform for embryology. M.G.C. and M.S.L. are full-time employees and stockholders/shareholders with TMRW Life Sciences, and A.M. of Novavax, Inc. was an employee of TMRW Life Sciences. G.P. is a consultant for TMRW Life Sciences. The remaining authors declare no conflict of interest., Trial Registration Number: NCT05326802; NCT05708963., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.)