Birth Variables and the Incidence of Cleft Palate: Part I

Abstract

It was the purpose of this research to study in a very large human population some of the variables which may be related to incidence of cleft lip and/or palate. Method The investigation (3) was based on 5,838,855 birth records obtained from 17 state departments of vital records and statistics. Information for these records was obtained, in most cases, from the attendant at the birth who was responsible for the accuracy of the data on the birth certificate. From the 5,838,855 records, 6,070 infants with cleft lip and/or palate were identified. A control group was arbitrarily selected by taking the record fifth in order after the cleft birth record appeared. If the fifth record also noted a cleft, the sixth was used for control. The data were stored and analyzed by electronic computer systems. States were selected for the investigation on the basis, generally, of whether or not they noted cleft palate specifically on the birth record and, in the same way, the number of years surveyed in each state was determined by how long such information had been reported in that state. Variables for Study Factors were selected for study on the basis of two criteria: apparent significance of the variable to the etiology of cleft palate, and the number of birth records on which this significant variable was included. A total of 18 were selected; they were arbitrarily'divided into three groups, generally depending upon the apparent temporal influences important in their determination: a) variables determined at conception (sex, color, plurality, maternal age, paternal age, birth order, and maternal nativity), b) variables related to gestation (length of pregnancy, associated anomalies , classification of cleft, complications of pregnancy, and prenatal care), and 0) variables related to birth (geographical location, urban-rural location, legitimacy, month, weight, and attendant). This report concerns data for the first group of factors. Dr. Donahue is associated with the University Park Psychological Center, Denver. 282