A nurse in the labor and delivery unit is caring for several clients. For which of these mother-baby pairs should the nurse review the results of the Coombs test to decide whether to administer Rho(D) immune globulin within 72 hours of birth?
1. Rh negative mother with Rh positive baby
2. Rh positive mother with Rh negative baby
3. Rh positive mother with Rh positive baby
4. Rh negative mother with Rh negative baby