Table 3

Association between estimated paternal serum TCDD concentration at time of birth and the probability of a male offspring, stratified by father's age of first exposure (estimated by father's age at start of employment)

Fathers employed at plant (n=127)
Age of father at start of employmentGirls (n)Boys (n)Sex ratioCrude OR95% CIOR*95% CI
23–30
 <4 pg/g lipid15240.621.00ref1.00ref
 4–20 pg/g lipid490.691.370.36 to 5.312.000.35 to 11.4
 20–100 pg/g lipid450.560.510.16 to 1.680.170.04 to 0.68
 ≥100 pg/g lipid310.250.200.03 to 1.370.040.01 to 0.26
p trend0.128p trend0.016
30–37
 <4 pg/g lipid24430.641.00ref1.00ref
 4–20 pg/g lipid350.630.940.19 to 4.751.260.20 to 8.08
 20–100 pg/g lipid12110.480.510.25 to 1.070.370.16 to 0.85
 ≥100 pg/g lipid870.470.490.12 to 2.090.590.18 to 1.95
p trend0.148p trend0.062
>37
 <4 pg/g lipid20210.511.00ref1.00ref
 4–20 pg/g lipid8100.561.200.42 to 3.482.020.78 to 5.21
 20–100 pg/g lipid14110.440.750.28 to 2.050.870.34 to 2.25
 ≥100 pg/g lipid22200.480.860.35 to 2.121.220.48 to 3.13
p trend0.625p trend0.934
  • *OR (modelling the probability of a male birth) adjusted for: age of parent at year of birth, current BMI of parent, smoking status of parent.

  • BMI, body mass index; TCDD, 2,3,7,8-tetrachlorodibenzo-p-dioxin.