Single umbilical artery

My congenital anomaly scan showed single umbilical artery, ang normal dw po 2 artery at 1 vein pero ang nkta lng po skn 1 arteey 1 vein ano po bmga risk ng gnitong kaso?? First baby q po ito nsa 27 weeks n po q, slmat po s mkakashare ng experience nya skn