Characteristics of pregnancy and birth and malignancy in the offspring (Sweden)

The aim of the study was to investigate whether factors of pregnancy and birth influence the risk of malignancy in the offspring.

Data on all deliveries (248,701 births) in two counties in Sweden 1955-90 were extracted from two birth registries. The follow-up period closed at the end of 1994 and the subjects were followed up to early middle-age at most (39 years). Incidence rates of malignancy were obtained from the Cancer Register 1958-1994. Standardized incidence ratios (SIR) and relative risks (RR) were calculated.

Overall, few associations were detected. A significantly increased standardized incidence ratio (SIR) of 50.00 (95% CI = 13.45-99.99) was found for the relationship between Down's syndrome and lymphatic leukaemia. Elder maternal age (> or =35 years) and lymphatic leukaemia were associated with a significantly enhanced risk (SIR = 2.00; 95% CI, 1.16-3.20). Maternal age 25-34 years, compared to younger age, was associated with a reduced risk of cervical cancer (RR = 0.47; 95% CI = 0.26-0.86).

Although some associations, the consistent pattern of non-association indicated a low impact of intrauterine environment or changed genetic material on the future development of malignancy in the offspring up to early middle-age.