Analysis of online information about success rates in fertility clinics in Spain. An urgent call for action.

Background: The medically assisted reproduction (MAR) industry is a booming sector of the economy, and Spain is proving to be a notable example of this industry's rise. Marketing strategies in the healthcare sector are shaped by the constant tension between providing clear, complete and appropriate information about treatments and providing information to attract and retain customers. Methods: We conducted a systematic analysis of success rate information published on the websites of Spain's five with the strongest online presence MAR clinics as of November 2023. The analysis examined terminology, certifications and audits by external bodies, references to data sources, age-specific success rates, and generalised claims about treatment effectiveness. Results: We identified significant deficiencies and ambiguities in how clinics present success rate data. Common issues included vague definitions, lack of certification details, absence of reliable data sources, and failure to differentiate outcomes by age or treatment type. Several clinics used overly optimistic or potentially misleading statistics, making it difficult for patients to assess their realistic chances of success. We provide recommendations aimed at improving consumer protection and regulating advertising practices. We also emphasise that presenting clear and truthful success rate information is not only a legal requirement but also an ethical duty in reproductive healthcare. Conclusions: Stronger regulation of success rate reporting in Spain's fertility sector is urgently needed. We recommend that external authorities oversee and standardise data reporting to ensure transparency and prevent misleading practices. A centralised public body should be responsible for monitoring, collecting, and managing this data to protect patient rights and improve trust in fertility care.