A more horrifying “family planning” practice than China’s one-child policy would be difficult to imagine. In effect between 1979 and 2015, the goal of the initiative was to curb population growth and thereby boost the nation’s economic status.

In practice, to name just a few of the abominations, women were sometimes tied down and subjected to forced abortions, the heads of live babies in utero were injected with formaldehyde before the feet emerged, and babies and young children were routinely abducted and trafficked.

The effects on fertility rates, divorce, labor supply, and rural-to-urban migration were devastating. Less measurable consequences — the damage to the human soul from being forced to snitch on one’s neighbors and family members, for example, the trauma to women of bodily violation, the imposition upon an entire population of a godless plan to engineer families — will leave scars lasting for generations.

“Daughters of the Bamboo Grove,” by former Los Angeles Times Beijing Bureau Chief Barbara Demick, carries the intriguing subtitle “From China to America, a True Story of Abduction, Adoption, and Separated Twins” (Random House, $32).

Partly investigative journalism, partly the story of what became Demick’s personal involvement in the reuniting of twin sisters separated by China’s one-child policy, the book explores questions of identity, history, the ethics of the international adoption system, the phenomenon of twins, and the role of genetics and environment in human formation.

One of the sisters, abducted from the family home at the age of 2, was adopted by a Texas family and thoroughly Americanized. The other, raised in rural China, by the time of the reunion had become a teacher.

The one-child policy, unthinkable almost anywhere else, was possible in China because of the lack of strong religious prohibitions against contraception and abortion, coupled with a highly authoritarian infrastructure. “Quality rather than quantity” became the catchphrase with respect to children even before the policy was put into place, as more and more women in the early 1970s began working outside the home.

But by 1979, writes Demick, “The era of gentle persuasion was over. Family Planning morphed into a monstrous organization that dwarfed the police and military in manpower,” and employed up to 83 million people.

“Enforcers” infiltrated every stratum of society, from university secretaries to village midwives and doctors. Female factory workers had to report the dates of their menstrual periods. After the birth of their first child, women were required to submit to the insertion of an IUD specially designed so as to be removable only by a medical professional.

Because male babies were favored over female, whether through abortion, abandonment, or trafficking, demographers estimate that more that 60 million girls went missing.

On Sept. 9, 2000, Yuan Zanhua, 28, gave birth in a bamboo grove deep in the mountains of Hunan Province. It was her third birth. Her first, a healthy girl, Ping, was born in 1995. Under the one-child rule, women were allowed to have a second child if the first was a girl, but only after a gap of five years.

Zanhua (the Chinese reverse the Western way of first and last names), and her husband, Zeng Youdong, had bypassed the rule and had a second daughter, Yan, only two years later. They’d been heavily fined; additionally, officials vandalized their home and stole their furniture. But they’d longed for a boy, and two years after that Zanhua was again with child. They had carefully hidden this third pregnancy for fear of the authorities.

And when the time came, Zanhua gave birth in the bamboo grove to twin girls. Mother and father were both thrilled — but also terrified. They’d been flagged by the enforcers already and to have two more children guaranteed severe punishment.

They hid, moved around, farmed the girls out to a grandmother, and at six months, separated them. Little Shuangje left the village with her parents; Fangfang — “the brilliant, beautiful girl who everyone in the family knew was so special” — moved into the home of an aunt and uncle.

When the toddler was two, a posse of officials forced their way into the home, restrained the aunt, and grabbed Fangfang, holding her aloft like a trophy as they left. Her parents, and her twin, Shuangje, would not see her again for almost 17 years.

Meanwhile, in 1991 China had enacted a law allowing foreigners to adopt Chinese children. They were quickly scooped up, especially young girls, and when the supply ran low, a black market in child trafficking opened up that thrived on abducting toddlers from their homes or the streets and bringing them to “orphanages.” In effect, and unbeknownst to them, many foreign adoptive parents actually paid a bounty to kidnappers.

The story of how Fangfang, later renamed Esther, and Shuangje were reunited, and the bureaucratic, legal, social, moral, and financial obstacles Demick had to overcome to facilitate the meeting, makes for a gripping read.

She treats all involved, including the American adoptive family, with sensitivity and compassion, thereby humanizing this complex, emotionally fraught situation.

Whether the twin raised in the West or the twin raised in the East is better off, by various measures, remains, interestingly, an open question.

One incontrovertible fact: China, suffering a drastic drop in birth rate, is now offering a $500 reward to parents for each of their children under the age of 3.