Transcript for Fertility clinic error led to baby being born in wrong family: Couple
And next, to the heartbreaking mixup at a fertility clinic, when a new York woman gave birth to two boys. They were not hers. Here's ABC's Adrienne Bankert. Reporter: Tonight, this baby boy at the center of two families unimaginable trauma. It was just -- it was heartbreaking. It was terrible. Reporter: Struggling to con vive, this California couple says they first turned to cha fertility, because of claims like this. We have the world's best facilities for infertility treatment. Reporter: After having a daughter in 2011, the couple returned to this los angeles-based fertility treatment center end undergoing an ivf procedure in August 2018. It failed. Months later, they were called in for a DNA test and to their horror told that a couple in new York, who had their ivf procedure on the same day, had given birth to their biological son. I felt my heart beating outside of my body. I was hysterically crying and I was just lashing out. Reporter: Weeks past before they won custody of their baby boy. Just imagine not knowing what that child is doing. It just drove me crazy. Reporter: Both families now suing for medical malpractice. The New York couple was expecting female asian-american twins, but when they delivered two male babies, neither of which was of Asian descent, they were shocked. DNA testing showed they were not related to the couple, or to each other. At every step of the way, cha has failed these couples. There needs to be accountability. Reporter: And David, we still haven't heard from the biological parents of the second child involved in this incident. We're told the New York couple wanted to keep both baby boys, but had to relinquish custody of them and still don't know what happened to their own embryos. Cha fertility has not responded. David? Just awful all the way around. Adrienne, thank you.
This transcript has been automatically generated and may not be 100% accurate.