Long-term effects of prenatal x-ray of human females. III. Mortality and morbidity.

Experimental studies and long-term studies of humans exposed to ionizing radiation in utero and after birth show that these exposures increase the risk of cancer in childhood and in later life. A possible life-shortening effect has also been reported. This study followed to their mid-twenties 1458 women exposed in utero to diagnostic x-rays and 1458 matched, unexposed controls in Baltimore, Maryland, and obtained responses from over 1100 women in each group. Information about general health and specific diseases was obtained from questionnaires. Deaths were ascertained through family members and death certificates. Mortality rates were slightly higher among exposed than control women, and did not differ by gestational age at the time of exposure. Exposed women reported poor general health significantly more often than controls. Specific diseases occurred similarly in the two groups, although exposed women reported more epilepsy or fits, more ovarian tumors, and more high blood pressure. The strong correlation between weight and high blood pressure and the heavier weights of exposed women seemed to account for this difference. In summary, these matched exposed and control women, followed to their mid-twenties, experienced similar rates of morbidity and mortality. Radiation-induced cancers and life-shortening effects, if any, might not become evident until older ages.