Infant sleep duration associated with mother's education level, prenatal depression and delivery method

Offering additional support for moms who had prenatal depression or gave birth by emergency C-section may benefit their babies' sleep, say researchers.

Newborn babies sleep less on average if their mothers do not have a university degree, according to a new University of Alberta study investigating the effects of socio-economic status on children's well-being.

Analyzing data from 619 infants and their mothers, the research team found that infants less than three months of age born to mothers without a university degree slept an average of 13.94 hours per day-23 minutes less than infants born to mothers with a university degree, and just short of the National Sleep Foundation guidelines of 14 to 17 hours of sleep per day.

"Sleep affects a baby's growth, learning and emotional development, and is one of the most common concerns of new parents," said Piush Mandhane, who carried out the study with fellow U of A pediatrics professor Anita Kozyrskyj and her master's student Brittany Matenchuk.

Of that 23-minute sleep shortfall for babies born to mothers without a university degree, researchers were able to pin 30 per cent of it to both a mother's prenatal depression and the type of delivery.

"Babies born by emergency caesarean section slept for an hour less per day than babies born vaginally," said Matenchuk.

"We really didn't expect to find this. Previous studies haven't reported on the sleep duration of infants born by emergency versus scheduled caesarean section past the first few days following birth."

Infants born by scheduled caesarean section were not found to sleep any shorter than infants born vaginally.

Kozyrskyj said earlier research showed an association between a mother's socio-economic status and shorter infant sleep duration, but this is the first study to determine which factors link the two.

"Mothers in distress tend to have sleep problems during pregnancy, which can be 'transmitted' to the fetus via the mother's nervous system and melatonin levels," she said.

She added maternal prenatal depression and emergency caesarean section also lead to elevated free cortisol levels during pregnancy and in the infant's cord blood at birth, respectively.

"This may cause an exaggerated stress response in infants that negatively impacts their sleep."

While other studies have focused on material wealth, the researchers elected to zero in on education because, with young families, "income may not provide a clear picture due to transient child care duties or parents finishing school," said Kozyrskyj.

"Infant sleep is one of the main concerns of new parents. Supporting mothers that have prenatal depression or experience an emergency C-section, and intervening during or after pregnancy, could help to increase infant and child sleep duration. That's our main target."

Matenchuk added anyone worried that their infant is not getting enough sleep should be encouraged to talk to their health-care provider about ways to improve infant sleep.

The researchers analyzed data from participants in AllerGen NCE's CHILD Cohort Study-a national birth cohort study collecting a wide range of health, lifestyle, genetic and environmental exposure information from nearly 3,500 children and their families from pregnancy to adolescence.

The study was published this month in Sleep Medicine.