A New York City couple is suing LA-based CHA Fertility Center after they carried twin boys to term that ended up being the biological children of two other couples who sought treatment at the center.

The couple said in a complaint that they only learned that the babies were not theirs after giving birth to the boys in March.

They were forced to relinquish custody to the boys' respective parents.

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In March, a couple who had long struggled to have kids gave birth to twins at a New York City hospital. But they knew something was wrong immediately when the two boys did not appear to be Asian, like themselves.

The unidentified couple is now suing their fertility clinic for unspecified compensatory and punitive damages, claiming the mistake led them to become impregnated with two embryos that were not their own.

They allege they have suffered irreparable emotional distress after having to give the newborns over to their biological parents.

According to the lawsuit complaint, the Queens couple said they had been hoping to have children of their own ever since they married in August 2012.

Unfortunately, their attempts to conceive a child naturally were unsuccessful, so they said they turned to the CHA Fertility Center in Los Angeles, spending more than $100,000 on IVF treatments.

A petri dish containing an embryo is seen in 2013. Richard Drew/AP

They said they entrusted the center to help them conceive through IVF since they were described as one of the "premier fertility treatment networks in the world."

Their first round of implantation failed, but a second, conducted in August 2018, was a success.

Read more: 10 things to know if you're considering IVF as a fertility treatment

The couple says a sonogram showed 2 boys instead of 2 girls

But there were soon signs that caused concern for the couple.

During their three- and five-month sonograms, doctors advised the mother that she was carrying two boys, when they had been told by the fertility clinic that they had been implanted with two female embryos, according to the complaint.

The couple said they called the clinic with their concerns but were told that sonograms were not always right and not to worry. So the couple took them at their word.

But when the mother gave birth via Cesarean section on March 31, she was greeted with two boys, according to the complaint. Even more shockingly, the babies were not of Asian descent, like their parents.

The complaint said the clinic's Dr. Simon Hong flew out to New York with some other staff members to meet with the parents at the hospital, and the couple underwent genetic testing, which determined that they were not related to the babies, and that the babies weren't related to each other, either.

The couple said in the complaint that the clinic determined the two babies were children of two separate couples who came to the clinic for fertility treatments.

"As a result, Plaintiffs were required to relinquish custody of Baby A and Baby B, thus suffering the loss of two children," the lawsuit reads.

The couple say they have "suffered significant and permanent emotional injuries for which they will never recover" and are seeking compensatory and punitive damages to be determined at trial.

CHA Fertility Center's COO did not immediately respond to INSIDER's request for comment.

Have you had a bad experience with CHA Fertility Center or another fertility clinic and want to tell your story? If so, contact our reporter at acollman@businessinsider.com.