[Incidence of cheilognathopalatoschisis in the Netherlands].

Until now, data on the incidence of cleft lip and/or palate in the Netherlands are scarcely available. For this study data were used from the National Medical Registration (NMR) and the National Obstetric Registration (NOR) over the years 1982 and 1983. Only children born in a general hospital have been registered. In the years 1982 and 1983 the NMR registered 295 children with the malformation just mentioned. The incidence calculated from these figures is between 1,38 and 1,77. The age distribution of mothers with a child with a cleft lip and/or palate (CLP) was compared to the total group of mothers. No correlations were found between the age of the mother and the birth of a CLP-child. The necessity of an accurate registration of congenital malformations in general in the Netherlands is emphasized.