March 1st is Baby Sleep Day!

Why is sleep so important for new families?

A child’s development depends on a multitude of factors, and sleep is a big one. We know that from the day a baby is born (and even toward the end of pregnancy), sleep is crucial for their physical and mental health — including growing, thinking, learning, and eventually speaking. 

“A baby’s brain goes through an enormous expansion in the first two years of life,” says Dr. Dani Dumitriu, a pediatrician, newborn hospitalist, neuroscientist, and the lead scientist of the COMBO Initiative. “And a ton of that growth happens during the first 6 months, when a baby’s brain doubles in size!” 

Sleep in infancy is key to supporting this early brain development, but we also know that it can impact a child’s development further down the line. As a baby gets older, they start to nap less during the day and sleep more at night. We call this “mature sleep,” and it’s an important sign that a growing baby is on a healthy track. In fact, one of our COMBO team members, Dr. Morgan Finkel, recently published a study showing that 6 month old infants who had more mature sleep patterns had better verbal skills at 7-8 years old.

“There aren’t many studies that are able to look at sleep in infancy and outcomes later in life,” says Dr. Finkel, also a general pediatrician. “As much as we know that sleep is important for older children, when it comes to infants, it's still unclear exactly which characteristics of sleep are most important, and how they affect children long term. This was one of the first studies to look at reported sleep in infancy and child outcomes through school age, and more consolidated nighttime sleep (a more mature sleep pattern) stood out as a characteristic that may affect long-term outcomes.”

For parents looking to support infant sleep, Dr. Finkel says a great way to start is learning to recognize early tiredness cues (like yawning or staring — fussiness is a late sign!) and responding to them using proven calming methods: swaddling, shushing, singing, and rocking. At around 6 weeks of age, she recommends starting a bedtime routine: ideally, this includes mutually enjoyable activities for parent and baby (like snuggling and sharing books), so that bedtime can be a relaxing time that supports a close relationship, instead of a stressful chore.

But there’s another piece of the sleep conversation that doesn’t always get talked about: a baby’s sleep (or lack thereof) also deeply impacts their family’s well-being. Just as sleep is crucial for babies, it’s key to new parents’ well being too. And research from our COMBO initiative shows that parents who feel tired or stressed during their baby’s first year are not alone. 

What have COMBO families helped us learn about sleep and stress? 

When babies aren’t sleeping well, their moms don’t sleep so well either. That’s understandable, especially during the postpartum period, when hormone levels are changing, and many new parents are sleeping close to their (sometimes restless) little ones. 

Sleep is so important for new parents’ physical and mental health, and even for their relationship with their baby. Not sleeping well can be connected to mental health struggles like postpartum depression and anxiety. And, vice versa, experiencing stress or mental health struggles can make sleep even harder. 

For example, when we looked at moms’ sleep during that first year of our study, we saw that more than half of our moms were getting fewer than 6 hours of sleep per night. That’s not their fault. It may be partly due to the stress of the pandemic — those who gave birth after the first big peak (March-April 2020), which was an especially stressful time, had a harder time falling asleep and staying asleep, and reported having lower quality sleep. 

The lead author on this COMBO study, Dr. Maristella Lucchini, says, “We often assume that new mothers don't sleep well because they have to attend to their child's needs at night — and that is definitely a big factor! But becoming a parent is so much more than feeding and changing diapers, especially when the transition to parenthood happens during a global pandemic. Stress and anxiety can greatly affect sleep, such that a mother might be tossing and turning in bed, even when her child is peacefully asleep.”

In fact, our research further showed that moms’ sleep is strongly impacted by stress and depression, and that pregnant and new moms were especially vulnerable to stress during the first year of the pandemic. Having less social support and experiencing disruptions in care during pregnancy, birth, or the postpartum period (like canceled prenatal visits) both had a big impact on moms’ stress levels and mental health. Dr. Lucchini stresses that these experiences don’t impact every family in the same way: “For example, our research showed that out of all the moms in our study, Hispanic moms experienced the worst sleep struggles postpartum, possibly because they experienced higher rates of Covid-positivity and more social and financial stressors.” 

So what can parents do to get better sleep?

If you or your baby aren’t sleeping well, you can talk to your baby’s pediatrician about tips for better sleep (for both of you)! Most new moms in the U.S. have just one visit* with their doctor at 6 weeks postpartum, and if they’re physically healthy, the next visit isn’t until 1 year after the birth of their child. If you’re at all worried about your own sleep or mental health, you can reach out to your doctor even if you don’t have an appointment scheduled. (*Under midwifery care, there may be more postpartum check-ins).

“It’s normal for infant sleep to be unpredictable and disorganized in the first weeks of life, so I discourage parents from trying to impose strict sleep schedules before 4 months of age,” says Dr. Finkel. 

Many parents are simply told to “sleep when the baby sleeps,” but that can be harder to do than it sounds. That’s why Dr. Finkel stresses that “social support is such an important piece of the puzzle. I recommend that parents plan in advance and reach out for as much social support as possible, to assist with other life responsibilities (for example, housekeeping and childcare for older children). That way, they can focus on the infant and, hopefully, sleep when the baby sleeps.”

COMBO data helped show that, indeed, social support and self-care during the pandemic helped pregnant and postpartum moms with sleep and energy levels. “We think it’s very likely that this finding applies to stressed parents more broadly than just in the pandemic setting,” says Dr. Dumitriu. In this study, self-care referred to exercising, getting a good night’s sleep, meditation, eating healthy, and calm activities like taking a bath. These “active” methods for coping with stress were better at helping moms feel resilient than “passive” coping methods, defined as increased screen time, social media use, and eating more comfort foods. 

In fact, the study showed that women who used passive coping methods were more likely to experience depression and anxiety than women who used active coping methods, with “vegging out” being linked to the worst energy and stress levels, and the highest levels of psychological distress. But active coping methods, like spending time with loved ones, were linked to better sleep quality and energy levels (especially for pregnant women). 

The main takeaway

Sleep is extremely important for babies — for their own healthy development and for their parents’ rest, recovery, and resilience. To a certain extent, disrupted sleep is totally normal for new families: infants haven’t developed a circadian rhythm yet! Even as they grow older, it will take years for them to transition to fully mature sleep patterns. But normal can still be stressful and tiring. If you felt (or feel) stressed or tired as a pregnant or new parent, you’re not alone. 

The childbearing year comes with so many changes. But there are things we’ve seen make a real difference for COMBO families’ rest and resilience: self-care and social support. We hope they make a difference for you, too.

Stay tuned for our upcoming study looking at the relationship between infant sleep and different measures of Early Relational Health, like bonding and emotional connection.