In an attempt to help those numbed by sleep loss, researchers conducted a series of experiments to find out which approach to crying infants soothes them best. After filming parents hugging their babies, carrying them, rocking them in a stroller and laying them down, the scientists came up with an optimal strategy, or at least one that did better than others. Writing in Current Biology, the team recommends parents pick up their crying baby, walk with them for five minutes – without sudden stops or sudden changes in direction – and then sit and hold them for five to eight minutes before lie down down again. “Excessive crying, especially during the night, is shown to be a significant source of parental stress,” said Dr. Kumi Kuroda, of the Riken Center for Brain Science in Saitama, Japan. “This 15-minute or so method is worth trying before they start seriously worrying about what’s going on with the baby.” The insight came from research on altronic mammals – those that are helpless at birth – such as cats, dogs, mice, squirrels and, most notably, humans. Studies show that when carried by their mothers, cubs become more docile, an effect called the “carrying response.” Because animals often move their young to avoid imminent danger, the response may have evolved through improved offspring survival rates. Researchers used video recordings and baby heart monitors to rank four different approaches to soothing crying babies: holding the child while sitting, putting the child in a crib, holding the child while walking, or rocking the child in a stroller or similar . The crying only decreased when the babies were in motion, either being rocked or carried. Sitting still with the baby or putting him in a bassinet did nothing to stop the tears. After being carried for five minutes, all of the crying babies had stopped crying and nearly half of them had fallen asleep, the researchers report. But even for those parents whose babies settled down, the danger wasn’t over. About a third of the babies woke up again almost as soon as they were put back to bed. To find out what set the babies off, the scientists looked at heart-monitoring data. This showed that the babies’ heart rates sometimes increased enough to wake them up when physical contact with the parent was broken. Trying to lay the baby down more gently made no difference. What helped was to sit with the sleeping baby for five to eight minutes after walking, so they fell into a deeper stage of sleep. While the approach worked better than others, scientists aren’t claiming it’s a magic bullet for sleep-deprived parents. The research on 21 infants in Japan and Italy is “exploratory”, with results that need to be checked in larger studies. “Babies can have sleepless nights for very different reasons,” said Gianluca Esposito, professor of developmental psychology and co-author of the paper at the University of Trento. “If the baby has a stomach ache, I don’t think this will do much. Unfortunately, I think many parents will still have sleepless nights. That’s part of being a parent.” Professor Ian St James-Roberts, who has studied soothing techniques for crying babies at UCL’s Institute of Education, said he hoped the team would continue their work. “There are other studies on the use of parental carry and they generally show that babies cry less when they are carried,” she said. “It would be good to know if these new, more detailed guidelines improve things further.” “Crying is an important and normal method of communication for babies – crying gives your baby a voice,” said Dr Betty Hutson at the Brazelton Center UK. “Babies have different cries for different needs, such as tiredness, discomfort, hunger or wanting to be held and played with. Over time parents learn through trial and error and experience what each cry means. There is no one response or strategy that fits the needs of all crying babies at all times – different responses will be appropriate at different times.”
