Irregular bedtimes during early childhood could disrupt children's brain power later in life, according to a study published in the online journal of Epidemiology and Community Health.
Researchers who are a part of the long-term UK Millennium Cohort Study (MCS), analyzed whether different bed times in early childhood were related to brain power in more than 11,000 7-year-olds.
The researchers tested the children against three areas of intellect - reading, maths and spatial awareness.
The study authors say: "Our findings suggest that inconsistent bedtimes, especially at very young ages and/or throughout early childhood, are linked to children's cognitive development.
"Relations between inconsistent bedtimes and aspects of early child development may have knock on effects for health and broader social outcomes throughout the lifecourse."
Research revealed that the most irregular bed times occurred at 3 years of age, with 1 in 5 children going to bed at varying times. At age 7, it was found that more than 50% of the children went to bed regularly between 7.30pm and 8pm.
At 7 years old, girls who had varying bedtimes had lower scores on all three areas of intellect, compared to children with regular bedtimes. However, this was not the case with boys.
Both girls and boys with irregular bedtimes at 3 years of age had lower scores in all three tested areas. Researchers say that this suggests the age of 3 could be a sensitive period for brain power development.
The MCS study analyzes children born in the UK between 2000 and 2002. This most recent research came from regular surveys and home visits of the children at age 3, 5 and 7 in order to find out about their family routines.
This is not the first study to draw a link between sleep and brain power problems in children. A previous study from the University of Arizona in Tucson found that obstructive sleep apnea - a respiratory problem that disrupts sleep - is associated in children with higher rates of ADHD-like behavioral problems and adaptive and learning problems.
The MCS researchers say that irregular bedtimes could disrupt natural body rhythms and cause sleep deprivation, and that this could undermine the physics of the brain and the ability to acquire and retain information.
The researchers add:
"Early childhood development has profound influences on health and wellbeing across the life course. Therefore, reduced or disrupted sleep, especially if it occurs at key times in development, could have important impacts on health throughout life."
The researchers also found that a range of social and environmental factors have an impact on bedtimes during early childhood.
The study authors say: "Families are prone to demands on time that might adversely impact on routines important for healthy development in young children. In light of this, policy development is needed to better support families to provide conditions in which young children can flourish."