Unless you are allergic to peanut, It is safe to eat moderate amount of peanut during pregnancy.
Peanut is rich in dietary fiber which can help to prevent constipation during pregnancy.
Peanut is also rich in iron which can help to prevent anemia during pregnancy.
Furthermore, peanut contains manganese, this mineral can help to make the bone stronger and healthier.
However, pregnant women should not eat peanut in excess. Peanut contains phytate, this compound will affect the absorption of calcium. This in turns will affect the healthy development of bone in the growing fetus.