Vetter R J
Radiation Safety Office, Mayo Clinic/Foundation, Rochester, MN 55905.
Health Phys. 1988 Aug;55(2):487-91. doi: 10.1097/00004032-198808000-00051.
Fertile women may be exposed to ionizing radiation as human subjects in medical research studies. If the woman is pregnant, such exposures may result in risk to an embryo/fetus. Fertile women may be screened for pregnancy before exposure to ionizing radiation by interview, general examination, or pregnancy test. Use of the sensitive serum pregnancy test has become common because it offers concrete evidence that the woman is not pregnant (more specifically, that an embryo is not implanted). Evidence suggests that risk to the embryo from radiation exposure before organogenesis is extremely low or nonexistent. Further, demonstrated effects on organogenesis are rare or inconclusive at fetal doses below 50 mSv (5 rem). Therefore, there may be some level of radiation exposure below which risk to the fetus may be considered essentially zero, and a serum pregnancy test is unnecessary. This paper reviews the fetal risks and suggests that consideration be given to establishing a limit to the fetus of 0.5 mSv (50 mrem), below which pregnancy screening need not include the use of a serum pregnancy test.
育龄女性在医学研究中作为人体受试者时可能会接触到电离辐射。如果该女性已怀孕，此类接触可能会对胚胎/胎儿造成风险。在接触电离辐射之前，可通过询问、常规检查或妊娠试验对育龄女性进行妊娠筛查。使用敏感的血清妊娠试验已变得很普遍，因为它能提供该女性未怀孕的确切证据（更具体地说，是胚胎未着床）。有证据表明，在器官形成之前，辐射对胚胎的风险极低或不存在。此外，在胎儿剂量低于50毫希沃特（5雷姆）时，对器官形成的已证实影响很少或尚无定论。因此，可能存在某种辐射暴露水平，低于该水平时可认为对胎儿的风险基本为零，血清妊娠试验也就没有必要了。本文回顾了胎儿风险，并建议考虑设定胎儿的辐射剂量限值为0.5毫希沃特（50毫雷姆），低于此限值时，妊娠筛查无需使用血清妊娠试验。
