MATERNAL AND PERINATAL RISK-FACTORS FOR CHILDHOOD BRAIN-TUMORS (SWEDEN)

Childhood brain tumors (CBT) include a diversity of rare neoplasms of largely unknown etiology. To assess possible maternal and perinatal ri sk factors for CBT according to subtype, we carried out a nested (with in Swedish birth-cohorts, 1973-89) case-control study utilizing data f rom the nationwide Birth Registry. We ascertained incident brain tumor cases through linkage of the nationwide Birth and Cancer Registries a nd randomly selected five living controls from the former, matching ea ch case on gender and birthdate. There were 570 CBT cases, including 2 05 low grade astrocytomas, 58 high grade astrocytomas, 93 medulloblast omas, 54 ependymomas, and 160 'others.' Risks for all brain tumors com bined were elevated in relation to: (i) three maternal exposures - ora l contraceptives prior to conception (odds ratios [OR] = 1.6, 95 perce nt confidence interval [CI] = 1.0-2.8), use of narcotics (OR = 1.3, CI = 1.0-1.6), or penthrane (OR = 1.5, CI = 1.1-2.0) during delivery); ( ii) characteristics of neonatal distress (a combined variable includin g low one-minute Apgar score, asphyxia [OR = 1.5, CI = 1.1-2.0]) or tr eatments for neonatal distress (use of supplemental oxygen, ventilated on mask, use of incubator, scalp vein infusion, feeding with a jejuna l tube [DR = 1.6, CI = 0.9-2.6]); and (iii) neonatal infections (OR = 2.4, CI = 1.5-4.0). Higher subtype-specific risks, observed for a few risk factors, did not differ significantly from the risk estimates for all subtypes combined for the corresponding risk factors. Childhood b rain tumors were not associated significantly with other maternal repr oductive, lifestyle, or disease factors; perinatal pain, anesthetic me dications, birth-related complications; or with birthweight,birth defe cts, or early neonatal diseases. These findings suggest several new le ads, but only weak evidence of brain tumor subtype-specific difference s.