Gestational risk factors and childhood cancers: A cohort study in Taiwan.

Gestational risk factors such as birth weight, gestational age and parity have been repeatedly found to be related to pediatric cancers, but few reports have emerged from Asian countries. Here we report on demographic and gestational factors in a Taiwanese cohort. Our study included all children born in Taiwan 2004-2014 for whom there was a birth record (n = 2,079,037), of which 1900 children had been diagnosed with cancer prior to age 12. We conducted multivariable hazard regression to examine associations between demographic and gestational factors with cancer. Greater parity (family with 2+ older children) was related to acute myeloid leukemia [Hazard ratio (HR) = 2.15, 95% confidence interval (CI): 1.31, 3.55), central nervous system tumors (HR = 1.67, CI: 1.13, 2.48) and neuroblastoma (HR = 1.67, CI: 1.07, 2.63). Hepatoblastoma cases had a higher risk of low birth weight (<2,500 g; HR = 3.01, CI: 1.85, 4.91), very preterm birth (<33 weeks gestation; HR = 13.71, CI: 7.45, 25.23), plural pregnancies (HR = 2.37, CI: 1.10, 5.14) and both small (HR = 2.13, CI: 1.23, 3.67) and large (HR = 1.83, CI: 1.01, 3.32) for gestational age. Germ cell tumors were more common among children born in rural areas (HR = 1.63, CI: 1.02, 2.60). Despite that Taiwan has lower rates of both high and low birthweight compared to other developed nations, we observed several similar associations to those reported in Western Countries. Further research should examine unique exposures in Taiwan that may be contributing to higher incidence of certain cancer types.