Pregnancy testing in patients undergoing radiation therapy

Radiation therapy (RT) can be lethal to a developing fetus; therefore, determining pregnancy status before RT is essential. We here sought to determine how many women treated with RT at our institution for over one year were at risk for pregnancy when starting RT. We retrospectively reviewed the medical records of all female patients 12–55 years old treated with radiation, i.e. 1 October 2012 to 31 September 2013. Patients were categorised as ‘at risk’ if they had a uterus and ‘no risk’ if they had a hysterectomy. Documented birth control, pregnancy test status, and timing of the pregnancy test in relation to the radiation start date were recorded. We included 131 female patients with a median age of 48 years (range 14–55 years). Breast cancer was the most prevalent disease site (18%) followed by head/neck and central nervous system (both 11%). Of the 131 patients, 35 were deemed ‘no risk’ and 95 (72%) were ‘at risk’. Pregnancy testing of the ‘at risk’ population was done in 47%, but only 17% of the pregnancy testing was performed accurately, which we defined as a test performed within 14 days before starting RT. Over one year, 66% (63/95) of ‘at risk’ women were not tested appropriately before starting RT. Most (66%) women of child-bearing age with an intact uterus receiving RT at our institution were not appropriately tested for pregnancy before the initiation of RT. These data laid the foundation for our formal pregnancy testing policies for women undergoing RT.