If parents want it to be done and if the procedure is done by people who know what they are doing, there is no ethical dilemmas here. Parents make such decisions for their child when the child cant consent to the procedure.
Parents make decisions on such things as heart surgeries when their infants can't consent -- things that aren't offered without actual life-threatening conditions -- with no ethical dilemma. But humans grow up healthy without circumcision -- it's not life-threatening.