Researchers in the USA measured foetal responses to a guided meditation designed to induce maternal relaxation during the 32nd week of pregnancy. The 18-minute guided imagery intervention generated significant changes in maternal heart rate, skin conductance, respiration period and respiratory sinus arrhythmia. Significant alterations in foetal behaviour were also observed, including decreased foetal heart rate (FHR), increased FHR variability and suppression of foetal movement. Significant associations were found between measures of maternal stress and foetal heart patterns, between lower umbilical and uterine artery resistance and increased FHR variability, and between declining maternal salivary cortisol and foetal activity. (Fetal responses to induced maternal relaxation during pregnancy. Biol Psychol 2007 Aug 31 [Epub ahead of print]).