Infant colic, young children's temperament and sleep in a population based longitudinal cohort study.

Background: Colic and sleep problems are common among infants, constitute challenges and distress for parents, and are often reasons for seeking help from health professionals. The literature debates whether infant colic and sleep problems are linked together or not. Further, limited evidence exists on how colic impacts on child temperament and sleep during early childhood. Thus, the purpose of this study was to increase our knowledge of the characteristics of infants with a history of colic compared to infants without, and to study how infant colic is associated with the development of child temperament and sleep over time.

Methods: The study is based on The Norwegian Mother, Father and Child Cohort Study (MoBa), a population-based cohort study conducted by the Norwegian Institute of Public Health. This sample contains 88,186 mothers and children. Data was retrieved from questionnaires distributed to mothers at recruitment (in pregnancy) and when the child was 6 months, 18 months, 3 years, and 5 years. Data was analysed using linear mixed models and GLM models for repeated measures.

Results: At 6 months, infants with reported colic are described as fussier, present more sleeping problems, are breastfed less, and the families visit the child health centre more often when compared to the non-colic group. Mothers of children with reported colic perceive their children's temperament significantly more challenging from the age of 6 months to 5 years. Further, children with reported colic were more likely to sleep less than recommended (22%) and to have more frequent night awakenings (14%) than usual for their age (6 months to 5 years).

Conclusion: Infant colic often occurs together with other signs of regulatory problems which may amplify the load on the parents. Moderate differences in temperament and sleep-problems across time, between those with colic and those without, indicate that the diagnosis of colic is moderately associated with later behavioural difficulties. However, it is demanding for the parents, and important to be aware of and act upon symptoms of colic in the child health centres to reduce the parents' load and prevent adverse long-term outcomes.