Fish consumption guidelines during pregnancy: are they effective in minimising mercury exposure in Spain?

Fish and seafood consumption provides essential nutrients for fetal and child development but is also the main source of human exposure to methylmercury, a neurotoxic substance of public health concern. To ensure safe consumption during pregnancy and early life, food safety authorities have issued recommendations; however, their integration into clinical guidelines and practice remains unclear. This study assessed whether fish consumption advice during pregnancy in Spain adequately addresses mercury exposure by integrating evidence from biomonitoring studies, guideline analysis, and healthcare professionals' practices. A scoping review identified studies measuring mercury biomarkers in pregnant women and children. In parallel, international, national, and regional guidelines in Spain were reviewed to evaluate the presence, accuracy, and clarity of recommendations. Additionally, a nationwide cross-sectional survey was conducted among healthcare professionals involved in maternal and childcare. The scoping review showed consistent evidence of mercury exposure in pregnant women and children, largely influenced by fish consumption patterns. Guideline analysis revealed substantial heterogeneity, frequent omissions of official recommendations, and the use of outdated or incomplete information. Survey results indicated limited awareness of official guidance among healthcare professionals and inconsistent communication of advice to pregnant women. Overall, despite the availability of scientific evidence and official recommendations, fish consumption advice during pregnancy in Spain is inadequately integrated into clinical guidelines and healthcare practice. Strengthening dissemination and implementation of clear, updated, and evidence-based recommendations is essential to support healthcare professionals and ensure safe fish consumption during pregnancy.