"Radiation exposure during the Learjet ride will not increase your risk of miscarriage. According to a recent paper (Bottollier-Depois J F, Chau Q, Bouisset P, Kerlau G, Plawinski L, Lebaron-Jacobs L. Assessing exposure to cosmic radiation during long-haul flights. Radiat Res. 153(5 Pt. 1): 526-32; 2000), the radiation exposure received by passengers during a Concorde flight is about 0.01 mSv (mSv—a unit of radiation dose) per hour. This is a good reference since the Concorde flies at approximately 55,000 feet and a Learjet may be between 40,000 and 50,000 feet. Put in perspective, that is about one day of normal background radiation (radiation exposure we receive every day from naturally occurring radiation sources). The dose that is allowed by the Nuclear Regulatory Commission for a pregnant woman who is occupationally exposed to radiation is 5 mSv."