From Wikia:
Sarada was born to Sasuke and Sakura Uchiha. Since Sakura refused to leave Sasuke's side during his journey, even while she was pregnant, Sarada was born in one of Orochimaru's hideouts, with Karin delivering her. As such, no records of her birth are available at the Konoha Hospital.[2][3] She grew up in Konoha predominantly with just her mother due to her father leaving on a long-term mission to search for the threat that Kaguya Ōtsutsuki was preparing for, although Sarada recalls her father holding her hand with her mother when she was a toddler, which hints that he was part of her life for the first couple of years before leaving for his mission. At some point, Sarada became ill and afterwards, began wearing glasses. Due to her father's absence, it led Sarada to question where her father was, as well as her own identity.[4]