No-one will be shocked to hear that having a baby can get in the way of a good night's sleep.

From the early days when you don't know what to do with a your newborn through to the nights when your toddler refuses to go to bed, sleep disruption is part and parcel of having children. Still, you mightn't have realised that just one little person may keep you up at night until well after they start primary school. Yes - according to a new study, parental sleep quality and duration don't recover to pre-pregnancy levels for up to six years. Researchers at the University of Warwick also found that mums sleep an average of an hour less a day for the first three months after the birth of a baby, compared to pre-pregnancy levels. Dads sleep an average of 15 minutes less in the same period. When children were between four and six years old, meanwhile, mums got average of 20 minutes less sleep than they did pre-pregnancy while dads got 15 minutes less. The study, which took into account 4,659 parents who had a child between 2008 and 2015, showed that the effect on sleep was more severe in first-time parents. Women who breastfed were also more likely to have disrupted sleep. "While having children is a major source of joy for most parents it is possible that increased demands and responsibilities associated with the role as a parent lead to shorter sleep and decreased sleep quality even up to 6 years after birth of the first child," Dr Sakari Lemola, from the Department of Psychology at the University of Warwick, told Science Daily.