Anatomical closure of ductus aeriosus gets completed by:

Under normal conditions, the ductus aeriosus closes functionally contraction of its muscular valve. Anatomical closure usually completed by intimal proliferation and takes 1 - 3 months i.e. by 3 month / 12 weeks ductus aeriosus should not remain patent. A patent ductus aeriosus is one of the most frequently occurring abnormalities of the great vessels (8/ 10, 000 bih)