Guidelines for Diagnostic Imaging During Pregnancy
ACOG Committee Opinion No. 299.
American College of Obstetricians and Gynecologists.
Obstet Gynecol 2004;104:647–51.
- Women should be counseled that X-ray exposure from a single diagnostic procedure does not result in harmful fetal effects. Specifically, exposure to less than 5 rad has not been associated with an increase in fetal anomalies or pregnancy loss.
- Concern about possible effects of high-dose ionizing radiation exposure should not prevent medically indicated diagnostic X-ray procedures from being performed on a pregnant woman. During pregnancy, other imaging procedures not associated with ionizing radiation (eg, ultrasonography, MRI) should be considered instead of X-rays when appropriate.
- Ultrasonography and MRI are not associated with known adverse fetal effects.
- Consultation with an expert in dosimetry calculation may be helpful in calculating estimated fetal dose when multiple diagnostic X-rays are performed on a pregnant patient.
- The use of radioactive isotopes of iodine is contraindicated for therapeutic use during pregnancy.
- Radiopaque and paramagnetic contrast agents are unlikely to cause harm and may be of diagnostic benefit, but these agents should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
- 胎兒在懷孕的前2~8 週內接受放射線照射，最容易引起畸胎。
- 放射線暴露若小於10 rad，一般不會對胎兒造成不良影響。
- 腹部斷層掃瞄的放射線暴露都大於50 rad，因此不能用於孕婦。