Never do this.
Never hold an infant or a child while riding in a
vehicle. Due to crash forces, an infant or a child
will become so heavy it is not possible to hold it
during a crash. For example, in a crash at only
25 mph (40 km/h), a 12 lb (5.5 kg) infant will
suddenly become a 240 lb (110 kg) force on a
person’s arms. An infant should be secured in
an appropriate restraint.