A longitudinal study of growth and development among prenatally exposed atomic-bomb survivors

Growth retardation due to A-bomb exposure has been evaluated for 455 individuals with nine repeated measurements of stature at age 10-18 yr using growth curve analysis and either two covariates, Dosimetry System 1986 (DS86) uterine absorbed dose and postovulatory age (weeks), or three covariates, DS86 uterine dose, DS86 uterine dose squared, and postovulatory age. Of the several comparisons made by city, sex, DS86 dose, and postovulatory age, the largest significant difference was found. However, on the basis of a linear-quadratic (L-Q) dose response, no significant difference was found. A highly significant growth retardation due to DS86 uterine absorbed dose was observed for all trimesters combined and for the first and second trimesters. In the first trimester, all parameter estimates based on a linear (L) or L-Q dose-response relationship were negative in relation to DS86 uterine absorbed dose. The parameter estimates in the second trimester were negative for a constant term and positive for an L or L-Q term. Radiation-related growth retardation at age 10-18 yr is clearly evident. The dose effect in the third trimester was not significant with either the L or the L-Q model. A growth analysis, based on an L dose-response relationship, was made for 704 and 838 children with four repeated measurements of stature from ages 10-13 and 15-18 yr, respectively. The retardation effect is clearly evident at age 10-13 and continues at age 15-18. Growth retardation in age 10-13 was highly significant for all trimesters combined but suggestive only for the first trimester. The group age 15-18 revealed a highly significant growth retardation for both the first and second trimesters. The relationship between birth weights and repeated measurements of stature in adolescence was discussed on the basis of the results obtained by a growth curve analysis. (J.P.N.)