(iStock)

Jessica Allen was already the mother of two boys when she decided to become a surrogate.

The pay she would receive to carry another couple's child to term — $30,000 — would allow Allen to become a stay-at-home mom, as well as save for a new house. It would also be her chance to help another family enjoy the blessings of a child, her partner, Wardell Jasper, told her.

So Allen signed up to become a surrogate with Omega Family Global, which matched her with a Chinese couple. In April 2016, after in vitro fertilization treatments, Allen became pregnant with the couple’s baby.

Six weeks later, the first of many surprises in her surrogacy would crop up: A second baby had appeared in her scans.

“I was a bit scared, but I heard the Lius were thrilled to be having twins,” Allen, 31, told the New York Post, which first reported the story and identified the intended parents using the “Lius,” a pseudonym. “My $30,000 payment, including expenses — which I received in installments by check each month — was increased by $5,000 for the second child. Not once during the pregnancy did any of the medical staff provided by the agency say that the babies were in separate sacs. As far as we were concerned, the transferred embryo had split in two and the twins were identical.”

Last December, Allen gave birth to both babies by C-section at a hospital in Riverside, Calif. She said she was not allowed to see the newborns or spend an hour with them, as her contract with San Diego-based Omega Family Global had outlined. She had only briefly seen a cellphone picture of them and remarked that they looked different.

“One was lighter than the other,” Allen told The Washington Post. “Their faces were not identical.”

Still, she hadn't gotten a full glimpse of the front of their faces — and besides, newborn babies change quickly, she reasoned. Only later would she realize how accurate her initial observation had been.

On Jan. 10, nearly a month after the babies were born, Allen said she received another picture of the twins from “Mrs. Liu,” who was concerned about their different appearances.

This time, both women could see they were not twins. In fact, they barely looked alike.

“I literally thought that the IVF mixed up some embryos because that happens, too,” Allen recalled. She began asking questions about the intended mother's husband, whom Allen had never met: “What about her husband? Does he have a different race? Does she have Caucasian in her family?”

Both of the intended parents were fully ethnically Chinese, she was told.

A DNA test would soon reveal the truth: One of the “twins” was actually Allen and Jasper’s biological son.

Despite using condoms, they had apparently conceived the child after becoming pregnant with the Lius’ baby, in what is believed to be an extremely rare case of superfetation.

The condition — in which an already pregnant woman conceives another child — is so rare that alleged cases are usually treated with skepticism. In a widely publicized 2009 case of a pregnant Arkansas woman becoming pregnant “again,” Karen Boyle, a reproductive medicine specialist, told ABC News that there were only about 10 reported cases of superfetation in medical literature.

Allen had never thought it was possible before her experience.

“I knew I was pregnant through the in vitro, but of course I didn't think there was another child forming,” she said. “I had no idea my body still naturally ovulated while I was already pregnant through in vitro.”

What followed was a lengthy, expensive legal battle as Allen and Jasper focused on getting their son back.

Omega Family Global reportedly told Allen that the Lius had relinquished the baby who was not their biological child — and also wanted up to $22,000 in “compensation.” In addition, the San Diego agency was requesting an additional $7,000 in expenses for looking after the child, she said.

Allen said she and Jasper couldn’t afford that and were shocked when agency officials put up other barriers to reuniting them with their son, such as saying they would adopt the baby out to recoup the money they owed the Lius.

“They took my son and kept him from me after DNA stated he belonged to me,” Allen said. “They just took it into their own hands and handled it however they wanted to handle it.”

In an interview with The Washington Post, Jasper put it more bluntly: “The main fact is, our child was kidnapped and held for ransom.”

The increasingly strained situation left the couple wondering what the agency was telling the intended mother, with whom Allen said she enjoyed warm communication — at first through a translation app, then in English — up until the delivery of the babies.

“I was so heartbroken and couldn't understand because we had a really good relationship throughout my pregnancy,” Allen said. “Toward the end, she was even telling me that she loved me.”

At some point after the DNA test, Allen said she received a concerned WhatsApp message from “Mrs. Liu” asking why Allen was going to sue them.

“They put it in her head that I was going to sue her. She started texting me like crazy,” Allen said. “I was like, no, we never said anything about suing you.”

Allen and Jasper hired an attorney. After a lot of “back and forth with our lawyers,” the agency agreed they did not owe the Lius any more “fees,” Allen said.

In response to a request for comment, Matthew Faust, an attorney for Omega Family Global, told The Post the agency had been “privileged to work with many gestational carriers over the years” but would not provide details because of patient privacy laws.

“Accordingly, because of these restrictions, Omega Family Global is unable to address any of the particular facts raised in this story,” Faust said. "Thus, although Omega Family Global has seen many false allegations made against its hardworking employees it feels legally bound to keep the true facts out of the limelight."

In an earlier statement to the New York Post, Omega Family Global disputed Allen’s claims as “made with reckless disregard for the truth.”

In the United States, commercial surrogacy — carrying another woman’s baby with monetary compensation beyond medical expenses — is legal only in a few states, including California, where Allen lives. The practice comes with a slew of ethical and legal questions, including what rights the surrogate mother and the child have, particularly when the surrogacy takes place in another country.

Although the Centers for Disease Control and Prevention publishes statistics on assisted reproductive technology, which includes “donor embryo services” and “gestational carrier services,” the federal agency’s data do not break out exactly how many of those births were by surrogacy. About 1.6 percent of all infants born in the United States each year are conceived using assisted reproductive technology, a figure that has doubled over the past decade, according to the CDC.

For Allen, her surrogacy was a “nightmare” that, she said, ultimately had only one silver lining: She was reunited with her son Feb. 5, in the parking lot of a Starbucks in Riverside County.

She and Jasper renamed their newest family member Malachi, and he is now 10 months old.

But their legal problems are “far from being resolved,” Allen said. Malachi has no Social Security card and no birth certificate — at least not one that shows his new name and biological parents.

“The only proof that I have is DNA,” Allen said. “It's like he doesn't even exist in the world.”

The couple said the agency should be held accountable for their child's lack of documents, as well as for how Allen claims its representatives “threatened, bashed, bullied [and] tried to scare me.”

Jasper and Allen are no longer are in touch with their original attorney, whom they hesitated to name, saying only that there are “no hard feelings.”

“We had to disconnect ourselves . . . because all she wanted was money,” Allen said. “We didn't have any more money for her. At the end of the day, she didn't know what else to do. We've just been praying and praying and praying and just hoping that one day something will happen.”

For months, they have sought new legal help, to no avail, she said.

“Our credit's been screwed over this; we have a really bad financial hardship over this,” Allen said. “Any of the attorneys that we've spoken with, nobody knows what to do, because this has never happened before.”

Months after they were reunited with Malachi, the couple came across a story of another surrogacy gone awry promoted by the Center for Bioethics and Culture Network, a California-based group that lobbies against surrogacy.

Allen contacted the group, which soon connected her with the New York Post. (The group did not respond to an interview request.)

Allen said she didn't want to go to the media, but she and Jasper decided they had no other options in their fight with the surrogacy agency. In the past week, their story has appeared in dozens of national and international media outlets, including People.

“It's just mind-blowing,” Allen said. “That's why we're putting our story out there because they need to see how badly [the agency] messed up from the very beginning . . . It's our reality and we still have a hard time wrapping our heads around it and how they allowed this to happen.”

Read more:

Discounts, guarantees and the search for ‘good’ genes: The booming fertility business

A model decided to tattoo her eyeball. She’s now partially blind and in ‘excruciating’ pain.

Georgia lawmaker says her remarks about quarantining HIV patients were misunderstood