Prenatal X-ray exposure and cancer in children

First reported in 1956, the relationship between prenatal x-ray and childhood cancer has been examined in more than a dozen studies. Although a positive association has not been found in all studies, in the two largest studies irradiation in utero was associated with a 40% to 65% increase in the risk of dying from cancer before the 10th birthday. A similar estimate was derived from a weighted combination of all studies published to 1964. The increased risk has been observed for all types of cancers examined. The results of extension of a study published in 1962 are reported in this paper