Problems arising in estimating from retrospective survey data the latent periods of juvenile cancers initiated by obstetric radiography.

Adrenal Gland Neoplasms/epidemiology Age Factors Child Child, Preschool Female Hematopoietic System/radiation effects Humans Infant Infant, Newborn Leukemia, Radiation-Induced/epidemiology Neoplasms, Radiation-Induced/epidemiology Pregnancy/radiation effects Radiography/adverse effects Retrospective Studies Time Factors