Table 4

Reproductive factors in the Swedish population (1980) and in the female cabin crew (1946–96) together with estimates from a Nordic meta-analysis of relative risk of breast cancer due to reproductive factors22

Reproductive factorsRR*PopulationCabin crew
No.%No.%
*Relative risks associated with reproductive factors in the Nordic countries.22
Parity
    Parous1.00217813973.2168572.5
    Nulliparous1.2979607726.863927.5
Number of children
    1–21.00154983171.1131478.0
    3–40.8454619725.136321.5
    5 or more0.69821113.880.5
Age at birth of first child (y)
    <201.0026171912.0110.6
    20–241.0485006439.01136.7
    25–291.1765597330.174844.4
    30–341.3027715212.862337.0
    >341.401332316.119011.3