NY- A Long Island woman and her husband are suing a Park Ave. fertility clinic for allegedly inseminating her with the wrong man’s sperm.

After struggling to conceive their second child, Nancy Andrews and her husband, Thomas, turned to New York Medical Services for Reproductive Medicine for in-vitro fertilization treatments, according to a lawsuit.

Andrews soon became pregnant and the couple was overjoyed. They only discovered the clinic’s “colossal blunder” after Andrews gave birth to her daughter Jessica, court papers charge.

“While we love Baby Jessica as our own, we are reminded of this terrible mistake each and every time we look at her,” the Commack couple said in documents filed in Manhattan Supreme Court. “It is simply impossible to ignore.”

Thomas Andrews is white and his wife is Dominican. But Jessica, who was born Oct. 19, 2004, has darker skin than either of them as well as “characteristics more typical of African or African-American descent,” the lawsuit states.

The couple tested their daughter’s DNA using a home kit and later with two more sophisticated methods. All three of the tests confirmed their suspicions – the tot has a different father.

“We underwent a difficult and complex medical procedure for the sole purpose of bearing a child of our own,” the couple said in court papers. “We were never informed that this type of mishap could occur, and frankly, this type of mishap is almost unimaginable.”

In legal documents, the couple said they were “emotionally devastated” when they found out Thomas Andrews, who had donated his sperm to be inseminated in his wife, was not the girl’s biological father.

“We fear that our daughter will be the object of scorn and ridicule by other children, both in school and as she grows up,” they said.

In a decision made public yesterday, State Supreme Court Justice Sheila Abdus-Salaam threw out parts of the couple’s lawsuit – including a claim that they had suffered mental distress.

“The birth of an unwanted but otherwise healthy and normal child does not constitute an injury to the child’s parents,” Abdus-Salaam wrote.

But the judge allowed the malpractice lawsuit to proceed against New York Medical Services for Reproductive Medicine. A previous court ruling already had found the clinic’s owner, Dr. Reginald Puckett, liable for inseminating Nancy Andrews with the wrong sperm, documents show.

The couple is seeking unspecified damages for the error.

Puckett’s attorney did not return calls yesterday.

The Andrews, whose eldest daughter was born on Christmas Day in 2002, declined to comment through their attorney.