May my wife take buscopan while pregnant?

Yes but: It is a class B2 which means the manufacturer recommends against it but there are no studies that show any harmful effects in the limited number of pregnant women who have taken it. No evidence in animal studies either.

No: I don't believe that any medication, either prescription or nonprescription, should be taken during pregnancy without checking with the obstetrician. I don't think buscopan can be considered safe to take during pregnancy due to its effect on smooth muscle. Your pharmacist would be another source of information about this matter.