The do’s and don’ts of modern pregnancy are well-known. Do get prenatal care, early and often. Do eat well; do exercise (in moderation); do maintain an appropriate level of weight gain. Do take prenatal vitamins and do be sure to get the recommended prenatal screens and tests. Don’t smoke; don’t drink alcohol. Don’t change the cat litter and don’t eat sushi. To this list of pregnancy prescriptions and proscriptions, comes another mandate: be happy, be calm, and avoid stress. Both the epidemiological literature and popular discourse increasingly emphasise the role of maternal emotions in birth outcomes.