Austrian public broadcaster ORF reported on the case in 2016 but back then the other family could not be found.
Ms Baumgartner was brought up not far away by Herbert and Monika Derler, according to ORF’s Thema TV programme. She discovered her blood type didn’t match that of her parents when she became pregnant, and a doctor informed her about the case of the switched babies.
Jessica got in touch with Doris via Facebook and they then met up.
She told the programme it was like meeting a sister.
“We got along right away,” Doris said. “It was an indescribably good feeling.”
Recently, the families finally met up too, filmed by an ORF TV crew.
Mrs Derler told the programme her first reaction on hearing the news was one of “emotional turmoil”.
“But my first thought was Jessica will always be our child. And when I saw Doris, I thought she is such a sweetheart.”
Meanwhile, Evelin Grünwald said: “For me, my family has just got bigger and I finally have certainty.”
“It was a relief,” her husband said.
The operations manager at the LKH-Uniklinikum in Graz, Gebhard Falzberger, was quoted by the broadcaster as saying: “We deeply regret that this mistake was made at the time.”
He apologised to both families on behalf of the hospital.
In 2016, the Grünwalds consulted a lawyer who advised them to adopt Doris, to ensure her inheritance rights, and got them compensation from the hospital, Thema reported.
The Derlers are now also pursuing adoption and compensation.
Jessica said it was good there was now clarity – but she admitted to having mixed feelings.
“It’s emotionally huge,” she said, “with beautiful sides to it but also a lot of pain.”