The white couple suing a New Jersey fertility clinic told The Post on Wednesday they “didn’t know what to think” when their daughter, conceived through IVF, developed “Asian features” — and the husband at first suspected his wife of cheating on him.

Drew Wasilewski and his now-ex-wife, Kristina Koedderich, claim the Institute for Reproductive Medicine and Science at Saint Barnabas in 2012 used a stranger’s sperm for their $500,000 IVF treatment.

“The hospital said this couldn’t possibly happen and there was no fault on their part,” Drew, 49, told The Post. “I started wondering, ‘Has my wife been cheating on me?’ What on Earth is going on here?”

The effect on their marriage was “just horrific,” added Kristina, 47.

The couple’s little girl was born in 2013, six weeks premature, and had to remain in the neonatal intensive care unit for a few weeks.

At that point, Kristina said, “she did look Asian,” but the couple “really just blew it off because we were just so glad to have a child.”

“She was healthy,” added Drew, who works as a driver for Coca-Cola. “We didn’t really focus on anything apart from how beautiful she was.”

About two years later, their daughter’s appearance began drawing questions from strangers that made the couple feel “horrible.”

“Everywhere we would go, even strangers would say: ‘Where did you adopt her?’ They just blatantly asked, even in shopping malls and places like that,” said Kristina, a medical technologist.

“We would try to blow it off,” said Drew. “And give them a look to stop asking questions … in front of the children.”

The couple have a son who looks more like them, and he added to the curiosity as people “compared her to him,” said Drew. Now 10½, their boy was conceived using fertility treatments, but not IVF.

Eventually, when their daughter was just over 2 years old in 2015, the parents had a DNA test done that confirmed there was “0 percent probability” that Drew was her biological father, according to their lawsuit filed in Essex County Superior Court.

“I was devastated. Shocked,” Drew said of the results. Meanwhile, Kristina “was in complete disbelief” and wanted to take the test again.

By November 2017, the couple of 12 years had split — in part because of their nightmarish ordeal.

“You start questioning everything,” Drew said. “What is going on? Is it the wife or is it the hospital? You are filled with all kinds of emotions. You’re confused. It’s extremely hard on your emotions. You don’t know how to deal with it.”

They now live apart but have tried to remain amicable for the sake of their children.

The parents said they adore their daughter but want to know the truth about how she was conceived.

“They love her very much, but it’s a very sensitive and very stressful situation for them,” said their attorney, David Mazie of Mazie, Slater, Katz & Freeman.

A judge last month ordered the clinic to hand over a list of men who donated sperm around the same time the couple used the facility — in hopes of narrowing down who the girl’s biological father is.

“I would like to find out who my daughter’s father is so I can have an answer for her when she asks, ‘Why do I look different?'” Drew said.

“I want her to know her genetic health history. And I don’t want this to ever happen to anyone else because it has been so difficult,” he said. “The last four years have been a nightmare. Why would someone deserve this when they are just trying to have a child of their own?”

Additional reporting by Tamar Lapin