Could genital warts be treated in pregnancy?

Yes if necessary. The only circumstance that requires treatment is if the condyloma are obstructing the birth canal. Otherwise treatment for condyloma is elective during pregnancy, be it for cosmetic or comfort reasons, be they physical or emotional reasons. Usually no treatment during pregnancy is the best approach.
Yes. There is no reason why they cannot be treated, however unless blocking the birth canal they can be watched. Often they will regress after the delivery.