A series of studies were carried out by Japanese researchers for a study that was just this week published in the journal Current Biology to see whether there is a good way to calm down and put to sleep a wailing baby, which is a common circumstance that can be frustrating for both parent and kid.

According to the research, the greatest technique is to carry a fussy child while strolling around for five minutes without stopping or turning abruptly. After that, experts advise sitting with them for five to eight minutes while holding them before gently putting them to sleep.

Researchers compared changes in infant heart rate and behaviour while a group of 21 mothers carried out activities often employed to soothe crying newborns using baby heart monitors and video recordings to reach this conclusion. The situations included carrying a baby while walking, pushing a stroller while holding a baby, holding a baby while sitting, and placing a baby into a crib or cot.

Baby data that was either asleep, awake and quiet, or crying was collected and evaluated accordingly.

After a five-minute walk, all of the babies in the study had stopped crying, their heart rates had dropped, and about half of them had dozed off. It didn't seem to help to hold a sobbing baby while sitting still. The baby's wailing and elevated heart rate were being monitored.

'Only for wailing newborns did a five-minute walk induce sleep. Surprisingly, this effect was not present when infants were already calm, according to Kumi Kuroda, the study's lead author and researcher at the RIKEN Center for Brain Science in Japan.

Babies were found to be very aware of their mothers' movements, according to the study. Heart rates went up when mothers turned or stopped moving, or when babies were taken away from their mothers.

When placed in their cribs for sleep before sleeping for around eight minutes, infants in the study frequently woke up. Because of this, experts advise spending five to eight minutes seated next to a sleeping infant after moving around to help them fall asleep deeper.

The latency from sleep start, according to Kuroda, was 'the crucial characteristic for successful laydown of sleeping newborns.'

Researchers have previously looked at the 'transport response' in other mammals, which occurs when a mother carries her newborn and causes the infant to become inactive and experience slower heart rates. Such a response was discovered by Kuroda and her team in both mouse pups and newborn humans.