Prenatal and perinatal risk factors for solid childhood malignancies: A questionnaire-based study.

IMPORTANCE:Childhood solid tumors account for the highest proportion of childhood cancers and are one of the leading causes of death in childhood. However, their pathogenesis is unclear. OBJECTIVE:To explore prenatal and perinatal risk factors for solid malignancies in children. METHODS:We enrolled 71 consecutive pediatric patients (44 boys and 27 girls; median age, 30 months) with solid tumors who were diagnosed and treated at our center from January 2013 to December 2016 as the case group. We also enrolled 211 age- and residence-matched healthy children (ratio of approximately 3:1 with the case group) as the control group. We conducted a questionnaire-based survey with the parents of these 282 children. Univariate and multivariate conditional logistic regression analyses of the collected data were performed. RESULTS:Confirmed solid malignancies included neuroblastoma (n = 32), rhabdomyosarcoma (n = 18), retinoblastoma (n = 7), renal tumors (n = 3), and other tumors (n = 11). Risk factors for solid childhood tumors in the univariate analysis were the parents' age, gravidity, parity, abortion history, vaginal bleeding, family history of malignancy, and prenatal use of folic acid or hematinics/iron supplements (P < 0.05), and those in the multivariate analysis were higher parity (odds ratio [OR], 2.482; 95% confidence interval [CI], 1.521-4.048), family history of malignancy (OR, 3.667; 95% CI, 1.679-8.009), and prenatal use of hematinics/iron supplements (OR, 2.882; 95% CI, 1.440-5.767). In contrast, use of prenatal folic acid was protective (OR, 0.334; 95% CI, 0.160-0.694). INTERPRETATION:A family history of malignancy, use of prenatal hematinics/iron supplements, and higher parity are risk factors for solid childhood tumors, whereas use of prenatal folic acid is a protective factor.