Best-selling author Jodi Picoult goes to great lengths to research her books. She has lived for a week on an Amish farm, trekked to the Alaskan tundra and gone ghost hunting.

For her latest book, A Spark Of Light, which takes on the tinderbox topic of abortion in America, she interviewed more than 150 women who had terminated pregnancies, sought out pro-life advocates and witnessed three abortions firsthand.

"Laws are black and white but the lives of women are a thousand shades of grey," says the 52-year-old American in an e-mail interview.

She is the author of 25 novels and has an estimated 40 million books in print worldwide. She is a fixture on sales charts - her last 10 novels debuted at No. 1 on the New York Times bestsellers list and her 24th novel Small Great Things (2016), in which an African-American nurse is charged with murder for trying to save the baby of white supremacists, spent 32 weeks on The Straits Times bestseller list for fiction.

A Picoult novel always promises melodrama and A Spark Of Light delivers on that front, opening seven hours into a tense stand-off between police and a lone gunman who has shot up a women's reproductive health clinic and is now holding the survivors hostage. One of them is the 15-year-old daughter of the police negotiator.

From there, the narrative unspools back in time, jumping between different characters, from the hostages - who include a wounded doctor, the young waitress whose pregnancy he just ended and an undercover pro-life activist - to the gunman himself, who believes his daughter had an abortion at this clinic.

Picoult, who has three children with her husband Timothy Warren van Leer, has mixed feelings about the abortion debate. When a friend in college got pregnant and decided to get an abortion at seven weeks, she supported her "100 per cent", she says.

But years later, she herself was seven weeks pregnant with her third child when she experienced complications and was told she might lose the pregnancy. "I was devastated - to me, that was already a child."

To prepare for the book, she spoke to five abortion providers and shadowed one - Dr Willie Parker of the West Alabama Women's Centre - during which she sat in on three abortions at five, eight and 15 weeks respectively.

The first two were over in less than three minutes, with unremarkable results. The third took seven minutes and produced "very, very tiny body parts - a hand, an elbow".

She was told the woman who had this abortion already had three children under the age of four and could not afford another.

Besides interviewing women who had been through abortions - whom she found mostly over Twitter and asked to fill out a 10-page questionnaire - she also spoke to pro-life activists.

"I expected them to be evangelical crazies," she admits. "However, they were lovely people who come from a place of deep compassion and truly believe that life begins at conception.

"That reminded me that although we think differently, we have to respect the opinions of others and, instead of judging, perhaps just listen."

She did not expect that A Spark Of Light's publication would coincide with the throes of a United States Supreme Court nomination that could lead to the overturning of Roe v. Wade, the 1973 landmark decision that ensures a woman has a right to abortion in the early months of a pregnancy.

She believes Justice Brett Kavanaugh, US President Donald Trump's pick for the Supreme Court, who was confirmed earlier this month, will "create barriers for a woman's right to choose her own reproductive healthcare".

She would like him to read A Spark Of Light. "Most specifically, I would like to pose this question to him: If the debate over reproductive rights is about the point at which a foetus becomes a person who has a right to bodily autonomy - then, by the same logic, at what point does the woman stop being a person who deserves the same right?"

Picoult, who says she has been writing since the age of five, is a self-avowed "workaholic" who has produced a novel almost every year since 1992.

Every weekday, she gets up early, runs five miles (8km), drinks a cup of coffee made by her husband and then writes in her attic from 7.30am until 4pm.

She will start a new book the day after finishing a previous one. In fact, she is already working on her 2020 novel, as well as a musical adaptation of Markus Zusak's World War II novel The Book Thief (2005) and a stage production of Between The Lines, the young adult novel she wrote in 2012 with her daughter Samantha van Leer.

Her work has been adapted numerous times for the screen, sometimes to her liking - she says she enjoyed the 2008 Lifetime adaptation of The Tenth Circle (2006), her novel about date rape - and sometimes to her chagrin.

The one that really disappointed her was the 2009 film of My Sister's Keeper, based on her 2004 novel about a girl who sues her parents because they want her to donate an organ to her ailing older sister.

The film ends differently from the book.

"The director lied to me and told me he would keep the ending - and then of course, he did not. I complained, was thrown off the set, told the head of New Line Cinema they were making a mistake - and sure enough, my fans were livid."

She often gets pigeonholed, especially as a "women's fiction author". Small Great Things recently won an award in Poland for "best romance novel" - despite nobody even kissing in the book.

"When a book is called 'women's fiction', it has less to do with the content than with the genitalia of the author," she says, adding that half her fan mail is from men.

"Female writers, in particular, need to continuously challenge the arbitrary label of women's fiction."

• A Spark Of Light by Jodi Picoult ($29.91) is available from major bookstores.