More than 30 years ago, I went to a parent meeting at my oldest child’s day care center, when he was in the 2-year-old room, and it turned out that many of the children in the room were not reliably sleeping through the night.
It felt like a revelation, discovering that mine was not the only child who occasionally — or regularly — woke in the night and needed some attention. In our family, we had come to terms with this, and we had managed to make — and generally keep — some rules: no food, no drink, no coming out of the crib, but yes, once a night one of your parents is willing to stagger down the hall, look in on you, rub your back and say something like, “We haven’t moved away and left you, now go back to sleep.” (Or maybe sometimes it was, “Go back to sleep or we will move away and leave you,” but that is lost in the mists of history.) It wasn’t ideal, but we were managing.
In the current issue of the journal Pediatrics, researchers describe a study of almost 400 mothers in Canada who were asked to report: “During the night, how many consecutive hours does your child sleep without waking up?” The researchers took six or eight hours of uninterrupted sleep as definitions of “sleeping through the night.”
They found that at 6 months of age, 62.4 percent of mothers reported that their infants slept for 6 hours or more at a stretch, and only 43 percent of the mothers reported eight-hour blocks of consecutive sleep. At 12 months, 72.1 percent of the mothers reported six hours of consecutive sleep, and 56.6 percent reported eight hours; since all infants wake several times a night, those who were reported as sleeping consecutively presumably awoke and went back to sleep by themselves without the mothers knowing it.
So by these criteria, a significant number of the babies were not “sleeping through the night” at 6 months, and even at 12 months. At some time points, girls were more likely to sleep for longer periods than boys, but at other times there was no significant difference.
The study found consistent associations between sleep duration and breast-feeding — at each age, the children with longer sleep durations were significantly less likely to be breast-fed — though again, there is no way to say anything about cause and effect here,
Marie-Hélène Pennestri, a psychologist who is an assistant professor of educational and counseling psychology at McGill University, who was first author on the study, drew a distinction between measuring those long blocks of sleep, and looking at other measures such as total sleep duration. “I wouldn’t want anybody to think I’m saying sleep is not important,” she said.
“My overall aim with this study was to lower guilt,” Dr. Pennestri said. More realistic expectations about young children’s sleep patterns might help parents cope, she said.
In future studies, she said, they will look at more objective measures of sleep, and also at parental expectations. The study also looked at child development, and found no significant differences between the two groups in their mental or psychomotor development.
The study also found no differences in maternal mood between those mothers whose babies were sleeping for those longer blocks and those whose babies were not, though links between infant sleep practices and maternal stress have been found in other studies.
Douglas Teti, a professor of human development psychology and pediatrics at Pennsylvania State University, has studied the social criticism that mothers sometimes undergo if they are continuing to keep the baby in the parents’ room after the age of 6 months (the American Academy of Pediatrics recommends that for reasons of safety, infants should sleep in the parents’ room — but never in the parents’ bed — for at least the first 6 months of life, and ideally for the first year).
In our culture, he said, parents who continue to keep the baby in their room often face such criticism, while co-sleeping is the norm in many other cultures. Their studies have found that persistent co-sleeping is associated with less happy marriages and higher stress around co-parenting, though again, this is an association; there is no way to tease out cause and effect. Mothers, he said, “appear to be particularly vulnerable to losing sleep,” and may accumulate chronic sleep deficits, which may affect their well-being and their functioning as parents. “A lot is going to depend on how the parent is reacting or responding,” he said. “One of the things we tell parents is pay attention to your own sleep schedules, use good sleep hygiene.”
Some mothers can tolerate those deficits better than others, he said. “Not everyone is showing stressed co-parenting or stressed marriages.” Both members of the couple need to be on board with decisions about where the baby sleeps, and how night wakings will be handled, he said, and they should make sure they are taking time to nurture their own relationship.
The new study, like many other studies of variability and temperament and the different ways to take care of children, ought to be reassuring to everyone — children develop differently and there are lots of ways to grow up and be healthy. Parents who are stressed or distressed by an infant’s sleep pattern should talk to their pediatrician.
“When a mother asks me to teach her behavioral sleep techniques, I’m happy to do it,” Dr. Pennestri said, “but if a mother asks me to teach her that because she has pressure from a nurse or a friend telling her, ‘Your infant should sleep through the night,’ I don’t think she should use it.”
The authors of this study are clearly concerned that mothers are being pressured by unrealistic expectations of when babies will sleep through the night. In the world of infant sleep, that brings up highly polarized issues — and that polarization has unfortunately been less than helpful to parents everywhere.
Children are very different, right from the beginning, and a single measure like longest duration doesn’t necessarily tell you what is going on in the home, or what the family’s night is really like, or how the parents are doing. Cause and effect are really complicated here, and the patterns that develop within families reflect both the parents and the baby, along with the culture and many other aspects of the family’s situation (socioeconomic status, housing arrangements, parental work and work-leave balance, other siblings). And most of all, perhaps, babies are temperamentally different, and there are good sleepers and less-good sleepers, and we have to love and nurture the ones we’re dealt.
The message ought to be that there is a lot of normal variation and that experts should help you, not make you feel bad, either about living with a child who wakes at night, or about strategies that help you decrease that waking.
Families who are doing just fine with a baby who doesn’t “sleep through the night” by some specific definition should not feel guilty or pressured.
There is no evidence that not sleeping through the night at 6 months — or 12 months — is bad for babies. On the other hand, though he doesn’t recommend it just because the baby isn’t sleeping through the night, “sleep training is not barbaric,” Dr. Teti said, “there are ways of doing it in a gradual way.” And studies of attachment and social and emotional development show no evidence that these methods of “graduated extinction” are bad for babies.
“There is no one recipe here,” Dr. Teti said. “It’s not just the baby you have to focus on. You have to look at the health of the family system.”