Incidence of Clefts in Israel

Abstract

A previous survey (unpublished) on the incidence of congenital cleft lip and/or palate was carried out in 1959. That incidence rate was found to be 1/1209 i 0.38%. That rate was lower than the usually reported frequency, and it was assumed that the difference between that rate and those rates reported in the literature might have been due to incorrect or incomplete registration of these malformations in our hospitals. It was, therefore, decided to repeat the survey on a larger scale after communicating with the Ministry of Health and giving instructions to the maternity wards for exacting registrations. The purpose of this paper is to define the incidence rates of congenital facial clefts among the Jewish population in Israel and to compare it with the incidence in other countries, as reported in the literature. Materials and Methods The records of the maternity wards in six regional hospitals in the different sections in Israel were screened. These hospitals were judged to provide a representative sample of the Jewish children born in Israel; indeed, 95% of all deliveries take place in those hospitals. Children of the different minorities were not included in the present survey, since it is not customary for their mothers to be routinely delivered in these hospitals and thus no valid registration of congenital deformities among such groups was available. The collected data were submitted to statistical analysis, that is, the incidence rate was estimated on the basis of 1,000 live births. For the statistical analysis, the chi square test was used to test the independence and the normal approximation for the binomial distribution. The level of significance was 5%. The total live births in each hospital were tested for differences with the remaining five hospitals. Differences in number of births between the years 1960, 1961, and 1962, and differ— ences between the sum total of live births in all six hospitals for each of the years were also tested.