Factors affecting dosimetry in pregnancy

Society has made attempts to reduce fetal exposure. Of note recently in the practice of medicine is the use of diagnostic ultrasound in obstetrics to supplant radiographic procedures. During the incident at Three Mile Island pregnant women were removed from the immediate vicinity to minimize internal contamination and thus fetal exposure. BRH is currently launching a public campaign to heighten public awareness of the need to question diagnostic x-ray procedures during pregnancy or suspected pregnancy. Despite these admirable intentions our pursuit of knowledge, at least when concerned with the fetal dose from internally deposited radionuclides, has been less than exemplary. There is a paucity of biological information available to determine the radiation absorbed dose to the fetus when the mother's body contains radioactivity, either by intent or by accidental exposure. The government has severely limited fetal research on humans with a net result of preventing the accumulation of valuable information. The delivered placenta, the study of which would yield currently unavailable information, has historically been treated with disrespect. Even in a well regulated American hospital, it is the only human tissue that can be discarded with the impunity. Unpredictable interspecies differences cause animal data to be tenuous and unreliable when quantitatively extrapolated to humans