In March 2013, Shen Jie and Liu Xi were on the cusp of starting a family — a scheduled in vitro fertilization procedure was only days away — when the Chinese couple's car slammed into a tree in Jiangsu province.

Liu was killed right away; Shen died five days later, reports said.

At the Nanjing Drum Tower Hospital, Liu's fertilized embryos sat in a tank of liquid nitrogen, preserved at minus-320 degrees Fahrenheit. For Shen and Liu's extended families, the frozen embryos became their only hope for a new generation.

The tragedy set off a years-long battle in court, as the parents of both Shen and Liu fought to claim the fertilized embryos as their own. The case, first reported by the Beijing News, presented myriad hurdles: The most daunting, perhaps, was that there was no legal precedent in China for parents to inherit the embryos of their deceased children.

Nevertheless, Shen's and Liu's parents tried a risky legal move — suing each other — in an attempt to get the Nanjing hospital to release the embryos to one of them, Beijing News reported.

After a year of court proceedings, the Wuxi People’s Intermediate Court ruled in favor of the would-be grandparents.

“The embryos left by Shen Jie and Liu Xi have become the only carriers of the bloodlines of both families,” the ruling stated, “and so they bear the burden of their grief and spiritual and emotional comfort.”

The Nanjing Drum Tower Hospital agreed to release the embryos — but only to another hospital, according to China Daily. Ding Lijun, a reproductive specialist at the Nanjing hospital, told the newspaper that the hospital sympathized with the couples but needed to carefully navigate uncharted ethical territory.

“There are thresholds for practicing every technology, and without the threshold, which we must strictly abide by, the technology runs the risk of being abused,” Ding told the newspaper.

At that point, a second major hurdle arose: Surrogacy has been illegal in China since 2001, when the Health Ministry banned it on “ethical principles,” and no other hospital in the country was willing to take in the embryos.

The parents of Shen and Liu eventually found a surrogacy agency that agreed to accept the embryos and bring them to Laos, a southeast Asian country where surrogacy was allowed.

When flying with the embryos presented challenges, the agency drove the embryos more than 2,000 miles to Laos in early 2017, Sina reported.

There, doctors implanted two of the embryos into a 27-year-old Laotian woman who would be the surrogate mother. One of the transplanted embryos was successful. During her pregnancy, the surrogate mother traveled to Guangzhou, China, on a tourist visa.

On Dec. 9, 2017, four years after his biological parents had died in a car crash, a baby boy was born by surrogacy in Guangzhou.

His grandparents marveled at his tiny features: The baby had his late mother's eyes, but overall, he resembled his father, they said.

They nicknamed him “Tiantian” (or “little sweet"), for the joy he brought after years of bitter legal battles and crushing loss. All four grandparents submitted DNA samples to prove that they were biologically related to the baby and maintain custody, according to the Beijing News.

On Tuesday, the newspaper released blurred-out pictures of the new family: In one, the four beaming grandparents gather around their unlikely grandchild.

In another, Tiantian — smiling, wearing a cartoon bib that says “HAPPY” — is about to celebrate his first 100 days, a significant milestone for newborns in China. In lieu of a large, ostentatious banquet, however, Tiantian's grandparents held a smaller affair, according to the Beijing News.

Tiantian's paternal grandfather told the newspaper that they didn't want to tell the child the truth about his parents until he was older. Instead, they would tell him that his parents had gone abroad.

“This child came into the world with sadness. Everyone else has parents to call them,” the grandfather told the newspaper. “We'll tell him in the future.”

The Colorado Supreme Court heard arguments Jan. 8 in the embryo custody battle of a divorced couple, Drake and Mandy Rooks. Here's what you need to know. (Monica Akhtar/The Washington Post)

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