WEDNESDAY, May 11 (HealthDay News) -- Infants' sleep patterns can be disrupted if their parents have severe relationship problems and are constantly arguing, a new study finds.
In addition, infants who heard regular blow-ups between parents when they were 9 months old continued to have troubled sleep patterns -- marked by problems getting to sleep and staying asleep -- even when they were 18-month-old toddlers.
The researchers found, however, that infants' sleep patterns had no effect on parents' relationships.
The findings were from a study by an international team of researchers, who analyzed data from more than 300 U.S. children and parents. All of the children were adopted at birth, which let researchers focus on how family relationships -- without the influence of genetics -- might affect the infants' sleep patterns.
"Regulated sleep is essential during infancy for healthy brain and physical development. Disrupted sleep patterns early in life have serious implications for children's long-term development," study co-author Gordon Harold, chair in behavioral genetics and developmental psychopathology at the University of Leicester, U.K., said in a university news release.
"How couples/parents relate to each other -- specifically, how they manage conflicts in their everyday lives -- is also recognized as having significant implications for children's long term emotional, behavioral and academic development," he added. "Understanding which comes first, children's sleep problems affecting parent relationship quality or parent relationship quality affecting children's sleep problems, has significant clinical implications."
The findings appear in the journal Child Development.
The Nemours Foundation has more about infants and sleep.