Pregnancy and delivery characteristics of women whose infants develop child cancer. A study based on registry information.

Data on all cancers among children born 1973-1984 were extracted from the Swedish Cancer Registry and linked to data in the Medical Birth Registry (1,268 cancer cases). For each case, two controls were selected, matched for maternal age, parity, county, and month of birth. A marginally increased risk of childhood malignancy was seen in the offspring of teenage mothers and at parity 1 and 4+. There was an excess among cases of the diagnosis physiological icterus. No statistically significant associations were found between childhood malignancy and infant sex, twinning, birthweight, non-chromosomal malformations, maternal smoking, or complications during pregnancy.