Infants and trauma

Does anyone else work with infants who have experienced abuse/neglect (other than the natural issues surrounding birthing, etc.) and what do you find to be your biggest therapeutic challenges? I see a number of infants/children from the foster care system, and the things they faced before placement are not things most of us can imagine for a child. What have you found to be most helpful? What are your personal challenges in dealing with these youngest clients?