TABLE 1

Maternal Risk Factors for Cancer in the Offspring

VariableNo. of ChildrenOR95% CITest for Trend
With Cancer (n = 6458)In the Population (n = 2 417 878)zP
Maternal age, ya1.47.14
    <2018660 8070.980.85–1.14
    20–241347464 9260.960.90–1.02
    25–292334861 0740.990.94–1.04
    30–341783695 0931.050.99–1.11
    35–39699284 1731.030.95–1.11
    40–4410449 9300.890.73–1.08
    ≥45518751.180.49–2.86
Paritya0.25.39
    126421 011 8041.000.95–1.06
    22317863 3571.000.95–1.06
    31034375 4600.980.91–1.05
    ≥4465167 2561.030.93–1.14
Smokinga1.48.13
    Unknown793202 276
    No42731 770 9341.00Reference
    <10 cigarettes per d834282 0910.990.92–1.07
    ≥10 cigarettes per d558162 5771.080.99–1.19
Previous miscarriageb0.94.26
    055072 007 7901.00Reference
    1737320 3000.960.88–1.03
    215766 2151.020.87–1.19
    ≥35723 5731.060.82–1.38
Years of unwanted childlessnessb1.18.26
    060512 267 0211.00Reference
    112844 5941.040.87–1.24
    29540 1350.940.77–1.15
    35022 0480.910.69–1.20
    43813 4661.130.80–1.55
    ≥59730 6141.180.96–1.44
BMIc0.89.27
    Unknown375227 366
    <19.8171109 5420.970.82–1.14
    19.8–25.91172752 6771.00Reference
    26.0–29.9272180 7481.020.89–1.16
    30.0–39.913996 5441.010.85–1.21
    ≥40.0863560.970.49–1.95
No. of infants in birthd
    162952 358 0461.00Reference
    215060 5131.070.90–1.27
    3415781.130.87–1.49
  • Women with perinatally dead infants and with infants without complete identification numbers were excluded.

  • a Adjusted for year of birth and for the other variables. For maternal age and parity, each group is compared with all other groups. One infant in population lacked parity information.

  • b Adjusted for year of birth and for the other variables.

  • c Adjusted for year of birth, number of previous miscarriages, and years of unwanted childlessness. Restricted to children who were born 1992–2005.

  • d Adjusted only for year of birth.