This book is the first of its kind on maternal stress during pregnancy and postpartum. The book offers a scientific overview on the association between maternal stress and its consequences in maternal and offspring health outcomes. Sources of maternal stress include daily-life stressors and also major stress such as natural disasters, violent conflicts, intimate partner violence, assisted reproductive technology, economic stress, the death of a relative and also birth-related stress. Maternal stress can cross the placenta, reach the developing foetus and produce epigenetic changes which can be associated with short- and long-term health and disease outcomes in both the mother and the neonate. Present scientific research on this topic offers some light into the complexity of this phenomenon, including the protective role of oxytocin against exposure to high levels of maternal stress.