[Review: Fetal risks in radiological examinations and estimated fetal absorption dose].

There has been growing concern about radiation exposure in the case of pregnant women who undergo radiological examinations. Lack of knowledge is responsible for the great anxiety and probably unnecessary termination of pregnancies. The main effects of radiation on the human embryo and fetus are prenatal death, growth retardation, congenital malformations and mental retardation as well as stocastic effect in lower doses. Prenatal doses from most properly performed diagnostic procedures present no measurably increased risk of prenatal death, malformation or impairment of mental development over the background incidence of these entities. The dose received depends on mAs, but other parameters are necessary for calculation (film source distance, kV, filtration). To prevent accidental irradiation of the fetus, women must receive information about radiation effects, and the physician must choose a nonirradiating technique. Termination of pregnancy is an individual decision affected by many factors. Fetal doses below 50 mGy should not be considered a reason for terminating pregnancy. For a low dose procedure such as a chest X-ray, the only information that may be needed is a verbal assurance that the risk is judged to be low. When fetal doses are above 1 mGy and above, more detailed explanation is given.