CHILDBEARING AND MORTALITY FROM CANCER OF THE CORPUS UTERI

Background. To investigate the mortality from cancer of the corpus ute ri in relation to parity and age at first and last birth. Methods. A c ohort of 431,604 married women aged 45-74 years at the Norwegian Censu s in 1970 was followed over 15 years. A total of 752 deaths from cance r of the corpus uteri were diagnosed during follow-up. Results. All ag e groups showed significant trends of decreasing mortality rates with increasing number of children. The age-adjusted reduction in mortality was 9.2% (95% CI 5.2-13.0) for each child. Women with 8-11 children h ad a relative risk of 0.35 (95% CI 0.14-0.85) compared to nulliparous women. For first birth at age >=35 years versus <=19 years, the relati ve risk was 0.53 (95% CI 0.34-0.83). No significant effect of age at l ast birth was found. Conclusions. This study supports the notion that high parity and postponing the first delivery may reduce the risk of u terine cancer death.