Board Thread:Boruto Discussions/@comment-29261733-20170713102406/@comment-32566479-20170713170151

In naruto Gaiden The Umbilical cord is actually Sakuras and Saradas but Suigetsu accidently said it was Karins by Mistake...And Karin helped deliver Sarada, meaning she helped Sakura give birth. At the end even Kishimoto confirmed that Sakura is the Mother of Sarada.