Babies with single ventricle congenital heart disease (SVCHD) are often diagnosed during pregnancy. While prenatal diagnosis has important clinical benefits, it is often stressful and overwhelming for parents, and many express a need for psychological support. HeartGPS is a psychological intervention for parents who receive their baby's diagnosis of SVCHD during pregnancy. It includes 8 sessions with a psychologist, coupled with tailored educational resources, and a personalized care plan. The intervention focuses on fostering parent psychological adjustment and wellbeing, and supporting parents to bond with their baby in ways that feel right for them. Through this study, the investigators will learn if HeartGPS is useful and effective for parents and their babies when it is offered in addition to usual fetal cardiac care. The investigators will examine the effects of the HeartGPS intervention on parental anxiety, depression, and traumatic stress; fetal and infant brain development; parent-infant bonding; and infant neurobehavioral and neurodevelopmental outcomes. The investigators will also explore mechanisms associated with stress biology during pregnancy, infant brain development and neurodevelopmental outcomes, and parent and infant intervention effects.