It’s a frustration many parents know all too well: You’ve finally lulled your crying baby to sleep, so you put them down in their crib … and the wailing begins again. Science might have a solution.
You can carry a crying baby for approximately five minutes, then sit for at least five to eight more minutes to calm the baby and put him to sleep. To put the child to sleep without disturbing themResearchers report September 13 in Current Biology.
These same researchers have previously shown that Carrying a crying baby calms the child’s heart and soothes it. (SN: 4/18/13). The new study examined the factors that can cause a crying baby not to wake up and to stay asleep.
Researchers used heart rate monitors to monitor 21 crying babies ranging in age between 7 and 9 months. The researchers also recorded videos of the infants’ moods while their mothers moved them around in a room and held them. They then placed them in a crib. The team was able to see how babies responded to different environments. This allowed them to monitor their heartbeats and observe whether they were fussy, crying, alert, or drowsy.
“We tested the physiology behind these things that tend to be kind of common knowledge, though it’s not really well understood why they work,” says Gianluca Esposito, a developmental psychologist at the University of Trento in Italy.
The babies’ heart rates slowed and they stopped crying when their mothers picked them up and carried them around for five minutes. Some infants fell asleep. The researchers found that infants responded to their parents’ movements regardless of whether they were asleep deep or not. For instance, a baby’s heart rate quickened if a parent turned quickly while walking or tried to put the baby down.
According to the team, sitting helps smoothen the transition from walking into bed. Babies cradled in mom’s lap for at least five minutes tended to settle into a slower heart rate and stayed asleep once they were put in their crib. Six babies whose moms sat down with them for less that five minutes noticed a faster heartbeat and woke up quickly.
There’s a lot of research about the relationship between infants and mothers, “but I had not seen work showing that infants were responding to mothers’ behaviors while infants were sleeping,” says Sarah Berger, a developmental psychologist at the College of Staten Island in New York who was not a part of the study.
Both Berger and Esposito caution this method isn’t a magic wand for all babies. It doesn’t rule out sleepless nights, but still, it’s something that parents can try, Esposito says. This study was conducted with mothers but anyone can do it. “Especially for very, very young kids … as long as these caregivers are familiar with the kid, it’s going to work,” he says.
