The study, led by Dr Fallon Cook, found that it's very common to experience difficulties with infant sleep at some point in the first year, with about 60 per cent of mothers reporting mild or fluctuating problems. But for 20 per cent of mothers their infants sleep problems are both persistent and severe during the first year.

"These mothers were more likely to have poorer mental and physical health during pregnancy in comparison to mothers of infants with no sleep problems," Dr Cook says.

The findings show that for some, infant sleep problems may have more to do with mother's wellbeing during pregnancy than with parenting style.

Until now it was unclear whether it was possible to predict which infants will have sleep problems. The current findings, along with other emerging research, suggest that severe and persistent infant sleep problems are linked somehow to mothers' wellbeing during pregnancy.

Dr Cook says this is an important finding because parents of sleep-disturbed infants often feel severely fatigued, depressed and anxious, and worry they are doing something to cause their infants sleep problems.

"Our findings suggest some infants may be predisposed to have sleep problems, despite parent's best efforts to help their infant sleep better," she says.

"Identifying and supporting mothers with poor mental and physical health during pregnancy is crucial. These mothers may benefit from more intensive support once the child is born.

“养育孩子不是睡好是前女友tremely hard. It's important that parents seek help from their GP or child health nurse if feeling depressed, anxious or exhausted, and reach out to family, friends, and local parenting groups for additional support."