Final answer:
A child in utero is at high risk if the mother contracts listeria because it can cross the placenta and infect the fetus, causing complications such as miscarriage, stillbirth, and premature birth.
Step-by-step explanation:
A child in utero is at high risk if the mother contracts listeria because listeria can cross the placenta and infect the fetus causing serious complications. In addition, listeria can cause miscarriage or stillbirth and listeria can cause premature birth. Therefore, the correct option is Option 4: all of the above.