Maternal preconception urinary levels of BPA were not associated with any birth size outcomes (see Additional file 2).
The general characteristics of mothers and children based on different categories of maternal preconception BMI and FA supplementation were compared using the chi-squared test and t-test.
Although intended primarily to replicate earlier studies of men (Gardner et al, 1990a, 1990b; McLaughlin et al, 1993), the study also examined the risk of maternal preconception exposure for various cancer diagnostic subgroups.
Table 1 gives the results of analyses for maternal preconception dose, in utero dose and status of exposure to internal emitters (monitored/not monitored).
A multivariable regression model was used to investigate the association between maternal preconception conditions and the risk of PTD.
In conclusion, the new data provide no evidence of an increased risk of childhood cancer associated with maternal preconception radiation work and thus, do not support our earlier finding of a raised risk in the offspring of female radiation workers.
The new data provide no evidence of an increased risk of childhood cancer associated with maternal preconception radiation work and thus do not support our earlier finding of a raised risk in the offspring of female radiation workers.
For example, the percentage of variation explained by maternal preconception concentrations was estimated as the preconception PCB coefficient sum of squares (0.15) divided by the total model sum of squares (0.679) = 22%.
In the four major groups, after adjustment for parental age and deprivation there were nonsignificant trends of increasing risk with number of cigarettes smoked for paternal preconception smoking and nonsignificant trends of decreasing risk for maternal preconception smoking (all P-values for trend >0.05).
Overall, the new data provide no evidence of an association between childhood cancer and maternal preconception radiation work, in contrast to the increased risk for childhood cancer overall and 'cancers other than LNHL' found in the original data.
