Pediatrician Harvey Karp (Tamara Leigh)

New babies don’t come with instruction manuals, so pediatrician Harvey Karp set out to create one for bewildered new parents with a five-step plan for what to do when a baby cries.

His book, “Happiest Baby on the Block,” was first published in 2002. It quickly became required reading for new parents, and has since been translated into 25 languages and sold millions of times.

Now, working with MIT-trained engineers and an industrial designer, the Los Angeles-based pediatrician has programmed his instructions into a high-tech bassinet he claims will help babies cry less and sleep more.

The smart crib is the latest twist on some age-old techniques that Karp popularized for an insatiable audience of parents who are raising children increasingly on their own, without support from extended family and the benefit of hands-on baby-care experience from their own upbringing.

“Although today’s mothers and fathers are very well educated, they are the least experienced parents in history,” Karp wrote in his 2002 book.

Few things will make a parent feel less prepared or more incompetent than not being able to calm down a crying baby. And babies cry a lot. About half of newborns cry or fuss for two hours a day, and about 15 percent cry or fuss for three hours or longer, Karp estimates.

His book outlines a reason for excessive crying. Babies are born too soon — while their heads can still fit through the birth canal but before their brains and bodies are quite prepared for the wider world. The first three months are known as the “fourth trimester,” and soothing a baby becomes a job of imitating conditions of the womb. Infants like to be tightly packed, carried around, surrounded by whooshing sounds. And Karp spells out a five-S solution for doing this: Swaddling babies, putting them in a side or stomach position, shushing them, swinging them, and offering them something to suck on.

Karp has promoted these techniques through curriculum and trained thousands of educators who work with parents in hospitals, support groups, military bases, schools and prisons.

Robert Hamilton, another Los Angeles pediatrician who recently popularized a different baby-soothing technique on YouTube, noted that many of the techniques have been around throughout time.

“The Five S’s are not mysteries,” Hamilton said. “But he put them all together, in an easy-to-read way, and that book took off. And he has helped a lot of people.”

New parents often struggle with very high levels of stress. About 15 percent of women who give birth each year, as well as some new dads, develop symptoms of postpartum depression, according to the Centers for Disease Control and Prevention. It often goes untreated, and stress and depression can lead parents to make decisions that are not safe, including hurting or neglecting their children. And exhaustion often leads parents to sleep with infants in soft beds where they are at risk of suffocation.

“If we can do something to reduce crying and increase sleep, we can prevent depression before it occurs,” Karp said.

A $1,160 crib?

One solution, Karp says, is offering stressed parents an extra hand in soothing their babies, so they can take a break and get some rest. His new crib — called the SNOO — will do that, he said. He is working with some universities to study the effectiveness of the crib as a tool for the treatment and prevention of postpartum depression.

The bassinet rocks and jiggles and plays white noise. It is outfitted with microphones that pick up a baby’s cries and respond accordingly, switching to a fast jiggling motion and louder white noise when baby is upset, then slowing to a gentle swing when baby falls asleep again.

The crib was first displayed at the American Academy of Pediatrics conference in San Francisco last fall. The $1,160 price tag for a bassinet that a baby outgrows after six months is bound to keep it off the baby registry for many. But Karp says the crib is the equivalent of a night nurse, a swaddle, a swing and a white noise machine. He is quick to point out that the price breaks down to $6 a day, not that much more than a sleep-deprived parent’s coffee bill.

And, he says, “it’s the only bed that gives you an extra hour or two of sleep at night.” That promise, if borne out in practice, is bound to make parents stop and consider when they outfit the nursery.

(Courtesy of Happiest Baby)

Denise Stern, the founder of Let Mommy Sleep, a night nurse agency, said she is curious to see how people will respond to the idea of a crib that rocks your baby for you. She hears a lot of pushback from people who criticize parents for outsourcing overnight duties with their children through night nurses, also at a high price tag. With the crib, she said, “it begs the question: Why don’t you just hold the baby yourself?”

But, she said, Karp’s work is meeting a very real and growing need in the United States, where the safety net for new parents is thin, including meager parental leave programs and little postpartum care.

“Our culture demands that families have help,” she said.

An earlier version of this post misidentified Robert Hamilton. The story has been corrected.