The association of cell phone use during pregnancy and during early childhood with behavioral problems in children was investigated in a cohort study in Denmark to confirm or refute a previous study by Divan et al (2008).
A new group of children (born between 1998 and 2002) of the Danish National Birth Cohort was analyzed in comparison to the 'original' group (born between 1997 and 1999) of the publication by Divan et al (2008), furthermore both groups were combined for analysis. In the new group of children, further confounders were considered: mother's and father's history of psychiatric, cognitive or behavioural problems as a child, gestational age, mother's prenatal stress, and child breastfed up to 6 months of age.
Behavioral problems in 7-year old children were assessed using the Strengths and Difficulties Questionnaire including 25 questions.
|Reference group 1||no exposure|
|Group 2||prenatal exposure|
|Group 3||postnatal exposure|
|Group 4||prenatal and postnatal exposure|
the original group comprised 12796 children
30.5 % children of the original group and 35.2 % children of the new group used a cell phone at the age of 7 years, but less than 1 % used a cell phone for more than 1 h per week. About 93 % of children had no recorded behavioural problems, 3.3 % were considered borderline, and 2.9 % of the original group and 3.1 % of the new group had behavioural problems.
The results showed positive associations between cell phone use and behavourial problems in young children. The highest odds ratios for behavioural problems were for children who had both prenatal and postnatal exposure to cell phones compared with children not exposed during either time period (OR 1.5, CI 1.4-1.7).
The findings of the previous study by Divan et al (2008) were replicated in a separate group of participants demonstrating that cell phone use was associated with behavioural problems at the age of 7 years in children.