Birth outcomes in women exposed to diagnostic radiology procedures during first trimester of pregnancy: a prospective cohort study

Abstract

Introduction Exposure of the embryo or fetus to ionizing radiations is a potential danger since it may induce clinically relevant fetal and/or neonatal damages. The aim of the present study was to examine fetal and neonatal outcomes after maternal exposure to radio-diagnostic procedures during first trimester of pregnancy, and to evaluate whether these effects might be related to the fetal absorbed dose of ionizing radiations. Methods A 10-year prospective cohort study was performed on 1979 pregnant women who underwent a radio-diagnostic procedure within the first trimester of pregnancy. Women were divided into two groups: those exposed to abdominal or lumbar radio-diagnostic procedure (Cohort A, n = 130), and those exposed to radio-diagnostic procedures in any other body regions (Cohort B, n = 415). Health physicists performed tailored fetal radiation dose calculation. Multivariate logistic regression model was used to estimate the risk of adverse pregnancy outcomes. Results The tailored fetal radiation dose was calculated for a total of 97 women (range 0.05-92 mSv). Major congenital malformations were detected in four infants in Cohort A, six infants in Cohort B, and 24 infants in controls (p = 0.445). Multivariate analysis confirmed the negative association between age and adverse pregnancy outcomes (OR 1.08 [1.06–1.11]), and the protective role of folic acid. A higher rate of small for gestational age seems to be present in women who underwent radio-diagnostic procedures that involve maternal thyroid. Conclusion Despite several limitations, our study confirms that exposure to radio-diagnostic procedures that may involve uterus at doses below 100 mSv does not increase the risk of embryo-fetal toxicity. The relationship between maternal thyroid irradiation and small for gestational age needs to be further investigated.