Analysis of the Morbidity and Mortality of Children Irradiated in Fetal Life

In 1948 a program of routine diagnostic pelvimetry early in pregnancy was carried out at the Chicago Lying-in Hospital. It was hoped that the knowledge gained would make the delivery and the outcome of labor easier and more predictable, and as nearly as we can determine nearly all the primiparas had routine diagnostic pelvimetry during that year. The roentgenography, usually performed at the time of the first or second prenatal visit, consisted of 10 X 12-in. frontal and lateral films obtained with a special machine previously described by Hodges for making orthodiascopic films (5). The target-to-film distance was 36 in. No filter or beam-defining diaphragm was used. The output of the machine in the various projections was measured and recorded at that time by J. W. J. Carpender and J. C. Nichols (4). From this information and from calculations and measurements made on a similar machine, it is estimated that the fetus received between 1.5 and 3 rads. In approximately half the infants who received the exposure in utero, the entire body and head were also exposed for five films on the first day of life. It is estimated that the newborn infant received less than 500 millirads. For all these procedures, the records of the Department indicate the actual kV, mA, and time of exposure as well as the number of films made. In 1958 we found the records of this procedure for 1,008 primiparas. After conducting a small pilot study to determine the feasibility of contacting the children involved, Paul Meier suggested that we establish control groups which might be used for comparison. Since routine pelvimetry was not performed before or after the 1948 study, 1,008 children born before the series and 1,008 born after conclusion of the pelvimetry series were selected. Thus, a total population of 3,024 children represented the total sample. Names were selected at random from each of the three groups, thus maintaining comparable years-of-risk. As of Sept. 19, 1966, 2,774 children were actually contacted by mail or telephone. Data from a questionnaire, together with any information we could obtain from the patient's physician, the child's hospital chart, autopsy reports, x-ray exposure data, and the mother's history including the prenatal record were carefully recorded on an eight-page computer work-sheet. Other hospitals furnished information concerning hospitalizations and operative procedures on these children. The history of the mother's health during pregnancy, of ingestion of drugs, and of hereditary diseases of the family was carefully recorded. The physicians and the families involved have been most co-operative in supplying information. Our biggest difficulty has been finding children placed for adoption through certain agencies in Chicago.