Cleft lip and palate is one of the most common congenital malformations affecting around one in 650 children. Despite the fact that in the developed world surgery is usually carried out for the condition at between three and four months people affected by it have been found to be at an increased risk of psychological difficulties including cognitive problems in infancy and early school, particularly with verbal IQ. Researchers have previously found an association with the quality of mother-child interaction at two months and cognitive development at 18 months; the theory being that shock, worries about forthcoming surgery, feeding problems and the difficulty of engaging with a disfigured child affect the relationship between a mother and her child, in turn affecting children's development. The same team of researchers, led by Francoise Hentges from the University of Reading, followed up a group of 170 children seven years later. 44 had early cleft-palate surgery, 49 late surgery and 77 were unaffected 'controls.' The study found that the children who had had cleft palate scored significantly lower on tests of cognitive development. This was mostly mediated by 'maternal sensitivity' at two months, even after allowing for the later effects of mother-child interaction. The study shows both how parents of children with cleft lip/palate need support from day one and how crucial the first few months are in a child's development.
Hentges, Francoise ... [et al] - The effect of cleft lip on cognitive development in school-aged children: a paradigm for examining sensitive period effects Journal of Child Psychology and Psychiatry doi:10.1111/j.1469-7610.2011.02375.x