ADVERSE REPRODUCTIVE OUTCOMES AMONG WOMEN EXPOSED TO LOW-LEVELS OF IONIZING-RADIATION FROM DIAGNOSTIC RADIOGRAPHY FOR ADOLESCENT IDIOPATHICSCOLIOSIS

In a cohort of women followed up for adolescent idiopathic scoliosis, we assessed the association between exposure to ionizing radiation fro m diagnostic radiography received in adolescence and subsequent advers e reproductive outcomes in adult hood. We estimated risk for unsuccess ful attempts at pregnancy, spontaneous abortions, low birthweight (<2, 500 gm), congenital malformations, and stillbirths according to dose t o the ovaries. We used regression models for binary and continuous out comes, accounting for key covariates and for clustering in the data th at arose from women having multiple pregnancies. Risks in the adolesce nt idiopathic scoliosis cohort were higher than in the reference group for unsuccessful attempts at pregnancy [adjusted odds ratio (OR) = 1. 33; 95% confidence interval(CI) = 0.84-2.13], spontaneous abortions (O R = 1.35; 95% CI = 1.06-1.73), and congenital malformations (OR = 1.20 ; 95% CI = 0.78-1.84), but the odds ratios did not increase monotonica lly by dose to the ovaries. There were fewer stillbirths (OR = 0.38; 9 5% CI = 0.15-0.97) and low-birthweight infants in the adolescent idiop athic scoliosis cohort (OR = 0.84; 95% CI = 0.59-1.21). Nevertheless, when the analysis of low birthweight was restricted to the adolescent idiopathic scoliosis cohort, the adjusted odds ratios were found to in crease by quartiles of dose (median dose of 0.69 cGy): 1; 1.43 (95% CI = 0.54-3.90); 2.24 (95% CI = 0.89-5.94); and 2.34 (95% CI = 1.02-5.62 ). We also found that the adjusted mean birthweight decreased with inc reasing dose by 37.6 gm per cGy (standard error = 23.5 gm per cGy). As sociations between adverse reproductive outcomes and ra diotherapy hav e been observed previously, but this is the first study in which an as sociation with birthweight has been found with diagnostic radiography.