Don’t Worry if Your One-Year-Old Doesn’t Sleep through the Night

A study conducted by McGill University, involving close to 400 young infants, has revealed that many healthy babies don’t start sleeping through the night until they are one year old. The aim of this study … Read more

Written by:

Derek

Last Updated: Sun, March 9, 2025

A study conducted by McGill University, involving close to 400 young infants, has revealed that many healthy babies don’t start sleeping through the night until they are one year old. The aim of this study was to explore whether infants who do not achieve six to eight hours of continuous sleep are at a higher risk for psychomotor or mental development problems. Fortunately for many parents, the research concluded that there is no relationship between irregular sleeping patterns in babies and developmental delays; as a result, there’s no need for worry if your child does not sleep without waking throughout the night. Additionally, the study found no evidence that the wakefulness of infants during the night affects the postnatal mood of their mothers.

New mothers and fathers typically expect their child to sleep through the entire night when it reaches six months of age. Pediatricians and other health professionals also always emphasize the importance of early sleep consolidation. However, a new study conducted by the McGill research team suggests that many healthy infants don’t reach that milestone when they are 6 or even 12 months old. Good news is that even if infants sleep less than six or eight a night consecutively, that won’t cause any problems with their psychomotor and mental development. There was also no association between children waking up at night and the postnatal mood of their mothers. The results of the study were published in the December issue of Pediatrics.

How Was the Study Conducted?

The scientists focused on analyzing information from past studies conducted in Canada about maternal adversity, vulnerability, and longitudinal birth cohort studies about neurodevelopmental trajectories in infancy and risk factors affecting those trajectories. The researchers have gathered information and analyzed almost 400 babies at six months old, and more than 350 infants at a year old. According to mothers’ reports, 38% of infants who were six months old were not sleeping consecutively from 6 to 8 hours per night. Further analyzes show that more than 50% of babies older than six months, but younger than a year weren’t getting eight hours of sleep without waking up. Lastly, around 40% of 12 months old infants weren’t sleeping straight at night from six to eight hours. Although there is no link between children waking up at night and the postnatal mood of their mothers, babies that get less consecutive sleep tend to breastfeed more. Breastfeeding is beneficial both for the mothers and their babies.

A “Gold Standard” Revision

In Western nations, sleeping through the night between six to twelve months old is considered the “gold standard”, and many professionals propose behavioral sleep training at an early age. Behavioral sleep training is well received among parents and very popular in Western countries. However, the lead author of the study, Marie-Hélène Pennestri from CIUSSS-NIM believe that the findings of her team won’t only allay some parental worries, but also lead to a revision of the “gold standard”. Dr. Pennestri advises parents to educate themselves on the normal development of infants, including the development of their sleep-wake cycles, and not to focus only on methods and interventions when sleep problems arise.

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