Expert review
Obstetrics
Fear of the unknown: ionizing radiation exposure during pregnancy

https://doi.org/10.1016/j.ajog.2011.12.001Get rights and content

Ionizing radiation during pregnancy can negatively impact a fetus. In light of the Fukushima nuclear plant disaster in Japan, we discuss existing knowledge on the health effects of radiation and preventive measures for pregnant women. Overall, the risk of exposure to radiation is limited but severe defects can result from fetal radiation exposure >100 mGy equivalent to 10 rad (>1000 chest x-rays). While such high-level exposure rarely occurs during single medical diagnostic procedures, caution should be exercised for pregnant women. As a protective public health measure in light of a disaster, evacuation, shielding, and elimination of ingested radioactive isotopes should all be considered. Detailed radiation reports with health effects and precautionary measures should be available for a population exposed to more than background radiation.

Section snippets

Radiation and measurement in dose units

Radiation, ie, any “energy that comes from a source and travels through some material or through space,”3 can be categorized as either ionizing or nonionizing. Nonionizing radiation “has enough energy to move around atoms in a molecule or cause them to vibrate, but not enough to remove electrons”4; examples include ultrasound waves, visible light, microwaves, and magnetic resonance imaging.

Ionizing radiation “has enough energy to remove tightly bound electrons from atoms, thus creating ions”4

Health impact of high-dose radiation from a nuclear disaster

The International Atomic Energy Agency developed the International Nuclear Events Scale to measure the health significance and environmental impact of all events associated with the transportation, storage, and use of radioactive materials (Table 3).18 Using the International Nuclear Events Scale, radiation exposure events are classified on a scale ranging from 1–7. Both the Chernobyl and Fukushima disasters were classified as a 7, the highest possible rating.

In a radiation disaster, the nature

Effects of radiation in pregnancy

The effects of ionizing radiation on an embryo and fetus can include: pregnancy loss, malformations, neurobehavioral abnormalities, fetal growth retardation, and cancer. The first 4 categories of adverse pregnancy outcomes have a deterministic effect whereby a threshold or No-Adverse-Effect Level (NOAEL) exists; however, once the radiation amount exceeds a certain level, all individuals will be affected. After exceeding the NOAEL, a deterministic effect typically shows a gradient relationship

Radiation exposure on infants and lactating women

Breast milk can become radioactive by a lactating woman's direct exposure to radiation on her breast or ingestion of radioactive pharmaceuticals or food. As with pregnancy, a lactating woman should be cautioned about the potential health effects before using medical diagnostics involving radiation. However, concerns about radiation exposure should not lead women to postpone or abandon critical medical treatment. X-ray exposure resulting from a single diagnostic procedure (eg, mammogram) is far

Protection of pregnant women and fetuses from radiation exposure

Precautionary measures for pregnant women from the effects of radiation-related adverse health outcomes are essentially the same as those for the general public. These measures are based on the following 3 principles: maintaining a safe distance, shielding one's body from exposure, and avoiding ingestion of food and water contaminated with radioactive particles in the air, rain, or soil.68

In case of a large-scale radiation disaster, such as the Fukushima incident, evacuation is the safest

Interventions to enhanced elimination of radioactive materials

The decorporation process, which refers to elimination of radioactive materials from the body, involves prevention of radioactive ion uptake and/or enhanced secretion and excretion of radio nucleotides. The best known measures for decorporation of radioactive iodine is the ingestion of potassium iodine (KI). Once the thyroid is saturated with nonradioactive iodine, it will no longer absorb any more iodine, radioactive or not, even if it is available for uptake. The KI tablets, which contain

Conclusion

In general, the risk of exposure to radiation causing health effects is limited, but can have a significant impact during disasters such as the recent incident in Fukushima, Japan. Public health departments should have detailed radiation reports available as soon as possible in case of a nuclear incident and inform the public of possible health effects and protective measures. Physicians and public health departments should be trained to give objective advice to concerned citizens on the health

References (79)

  • The medical aspects of radiation incidents

    (2011)
  • Alpha particlesUnderstanding radiation

  • MeasurementGuidance for radiation accident management

  • Understanding radiationRadiation emergency medical management, May 20, 2011

  • Sources and effects of ionizing radiation

    (2010)
  • S.M.J. Mortazavi

    High background radiation areas of Ramsar, Iran

    (2002)
  • F. Cunningham et al.

    General considerations and maternal evaluation

  • H.T. Winer-Muram et al.

    Pulmonary embolism in pregnant patients: fetal radiation dose with helical CT1

    Radiology

    (2002)
  • J. Chen et al.

    Estimate of doses to the fetus during commercial flights

    Health Phys

    (2008)
  • M.M. Chen et al.

    Guidelines for computed tomography and magnetic resonance imaging use during pregnancy and lactation

    Obstet Gynecol

    (2008)
  • S. Ratnapalan et al.

    Physicians' perceptions of teratogenic risk associated with radiography and CT during early pregnancy

    AJR Am J Roentgenol

    (2004)
  • S.A. Lowe

    Diagnostic radiography in pregnancy: risks and reality

    Aust N Z J Obstet Gynaecol

    (2004)
  • J. Valentin

    ICRP publication 84: pregnancy and medical radiation

    (2000)
  • The International Nuclear and Radiological Event Scale

    (2008)
  • K.R. Brown et al.

    Acute and chronic radiation injury

    J Vasc Surg

    (2011)
  • J. Valentin

    ICRP publication 105: radiological protection in medicine

    (2007)
  • Health effects of the Chernobyl accident and special health care programs: report of the UN Chernobyl Forum Expert Group “Health”

    (2005)
  • Health effects due to radiation from the Chernobyl accidentAnnex D of UNSCEAR 2008: sources and effects of ionizing radiation. Volume 2: Effects

    J Radiol Prot

    (2011)
  • E. Cardis et al.

    Cancer consequences of the Chernobyl accident: 20 years on

    J Radiol Prot

    (2006)
  • E.B. Douple et al.

    Long-term radiation-related health effects in a unique human population: lessons learned from the atomic bomb survivors of Hiroshima and Nagasaki

    Disaster Med Public Health Prep

    (2011)
  • L. Ilyin et al.

    Radiocontamination patterns and possible health consequences of the accident at the Chernobyl nuclear power station

    J Radiol Prot

    (1990)
  • M.P. Little

    Cancer and non-cancer effects in Japanese atomic bomb survivors

    J Radiol Prot

    (2009)
  • D.B. Richardson

    Exposure to ionizing radiation in adulthood and thyroid cancer incidence

    Epidemiology

    (2009)
  • D.B. Richardson et al.

    Positive associations between ionizing radiation and lymphoma mortality among men

    Am J Epidemiol

    (2009)
  • R.E. Shore et al.

    Epidemiological studies of cataract risk at low to moderate radiation doses: (not) seeing is believing

    Radiat Res

    (2010)
  • J. Harrison et al.

    The assessment of doses and effects from intakes of radioactive particles

    J Anat

    (1996)
  • R. Ritenour

    Health effects of low level radiation: carcinogenesis, teratogenesis, and mutagenesis

    Semin Nucl Med

    (1986)
  • M. Helewa et al.

    Breast cancer, pregnancy, and breastfeeding

    J Obstet Gynaecol Can

    (2002)
  • P. Fattibene et al.

    Prenatal exposure to ionizing radiation: sources, effects and regulatory aspects

    Acta Paediatr

    (1999)
  • Cited by (0)

    The authors report no conflict of interest.

    Reprints not available from the authors

    View full text