One of the rites of passage into parenthood are those first few bleary-eyed months when soothing an infant to sleep seems like an impossible dream. All the lullabies, rocking, feeding, swaddling — hour after hour, night after night — can be exhausting. Many parents find themselves desperate at 2 a.m., wondering if they will ever find a golden pillow at the end of their sleepless nights.
Sleep problems are highly prevalent in infants and toddlers, occurring in approximately 20 to 30 percent of young children, according to Jodi A. Mindell, PhD, a psychologist in the department of Child and Adolescent Psychiatry and Behavioral Sciences and the division of Pulmonary Medicine, as well as the associate director of the Sleep Center at The Children’s Hospital of Philadelphia. Using an online tool as an innovative form of data collection, Dr. Mindell conducted a study to evaluate the sleep patterns of young children between birth and 35 months. Her findings about their bedtimes, wake times, night-time sleep duration, nap sleep duration, and sleep consolidation may offer groggy parents a glimmer of reassurance.
“This is real-world data that we collected on a night-to-night basis,” Dr. Mindell said. “It gives us a beautiful way of visualizing what infant sleep looks like in the U.S.”
Dr. Mindell and her study team collected data from the digital sleep diary function within a free publicly available iPhone/iPad app for sleep in young children. Overall, the study analyzed 156,989 sleep log sessions involving 841 children over a 19-month period, and the results appeared in the Journal of Sleep Research.
Narrowing down all that data was the biggest challenge for the study team, Dr. Mindell said, but the advantage is that these emerging technologies gave them a wide geographical reach. They also allowed for direct data capture, which increased accuracy because the researchers did not need to rely on parents’ recollections and verbal reporting.
While every baby is different, Dr. Mindell said a clearer image of how sleep patterns develop in the first few years began to emerge. For example, the results suggest that nighttime sleep becomes more predictable at an earlier age than daytime sleep. Between five and six months sleep patterns start to develop more clearly, with the majority of babies sleeping for longer durations, on average about 10 ½ hours. It isn’t until babies are eight months old that the duration and time of day of naps became more consistent, with most babies taking two naps a day of about 1 ½ hours each.
“The take-home message is that parents need to hang in there for those first three or four months because then you’re going to start to see some better predictability,” Dr. Mindell said.
Also, the study showed that while there was a wide variation of bedtimes, morning wake times were consistent for babies of all ages, with most starting their days around 7:15 a.m. This finding reinforces that differences in bedtimes are important, Dr. Mindell pointed out. For every hour that bedtimes were later, infants’ total sleep duration decreased by almost 30 minutes.
“The later your baby goes to bed, the less sleep he or she is going to get,” Dr. Mindell said. “Because morning wake times had very little variability, sleep duration is really driven by bedtime.”
In addition to giving parents the ability to track their young children’s sleep, the mobile app has an “Ask the Expert” section that also yielded valuable research insights into parents’ primary sleep concerns. In a previous study published in the journal Behavioral Sleep Medicine, Dr. Mindell and her research team analyzed 1,287 questions that were submitted across a 10-month period. The researchers revealed that parents’ top three pediatric sleep worries centered on the themes of night wakings, sleep schedule, and bedtime problems. For example, a common question was, “My 3-month-old will not sleep on her own. What can I do? As soon as I take her out of my arms, she wakes up and cries until picked up.” Dr. Mindell, who responds to the Ask the Expert questions, receives an influx of such questions before she arrives to her office each morning.
“About 35 percent of the questions come in overnight, which demonstrates that parents need access to information at all hours of the day, not just when their pediatrician’s office is open,” said Dr. Mindell, who typically replies in about two days. “That is how the app helps.”
She developed the app almost four years ago in conjunction with Avi Sadeh, a professor at Tel Aviv University's School of Psychological Sciences and Johnson & Johnson Consumer Companies, to give parents easy access to empirically based pediatric sleep information and strategies. In addition to Ask the Experts, another popular feature of the app is its downloadable lullabies.
From the very beginning of the app’s conceptualization, the app’s creators included a research component. When parents download the app, they must agree to be research participants, and so far about 300,000 people have done so. Each time a user answers the apps’ series of questions in order to generate a customized sleep analysis and receive personalized recommendations, it builds the database that is available for researchers to analyze. In the future, they plan to insert particular research questions into these questionnaires that they’d like to explore. The app recently launched globally, and Dr. Mindell is excited to be able to start collecting data to compare infant sleep patterns from throughout the world to the researchers’ U.S. findings.
“Mobile technology is a unique way to do sleep research and to collect data across the globe and include dramatically larger groups that we can then look at very closely,” Dr. Mindell said. “You lose some specificity, but what you get is an incredibly large snapshot of sleep.”
Dr. Mindell also is a professor of psychology and director of Graduate Psychology in the department of Psychology at Saint Joseph’s University.