A study slated for Nature Communications in 2026 reports that human chorionic gonadotropin (hCG) exposure on the trigger day in assisted reproductive technology (ART) can affect DNA methylation patterns and neurodevelopmental-related outcomes. The work, by Jiang, Wei, Liu, and colleagues, is positioned as evidence that biochemical cues during fertility treatment cycles may carry measurable downstream effects. The article describes an approach that connects trigger-day hCG exposure to epigenetic modulation, using the term “trigger day” to refer to the cycle point when hCG is administered to initiate oocyte maturation. It frames the findings as relevant for ART optimization and long-term offspring monitoring. Although the excerpt provides limited outcome specifics, the direction aligns with growing attention to how cycle-level signals may influence developmental trajectories via epigenetic mechanisms.