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Table 2 Odds ratios (OR) for a male birth among offspring from parents in the Michigan Long-Term PBB Study with enrollment serum PBB concentrations

From: A cohort study of the association between secondary sex ratio and parental exposure to polybrominated biphenyl (PBB) and polychlorinated biphenyl (PCB)

   N (%) Crude^ Unadjusted * Adjusted **
Exposure Variables (μg/L)   Offspring OR (95% CI) OR (95% CI) OR (95% CI)
Model 1 (Maternal enrollment PBB only):     
   Maternal PBB   865    
   < 3   477 (55) 1.00 1.00 1.00
   ≥ 3   388 (45) 0.92 (0.70, 1.21) 0.93 (0.72, 1.20) 0.93 (0.72, 1.20)
Model 2 (Paternal enrollment PBB only):     
   Paternal PBB   300    
   < 6   160 (53) 1.00 1.00 1.00
   ≥ 6   140 (47) 1.11 (0.70, 1.75) 0.95 (0.65, 1.39) 1.18 (0.76, 1.83)
Model 3 (Maternal and Paternal enrollment PBB combined):   
Maternal PBB Paternal PBB 300    
< 3 < 6 120 (40) 1.00 1.00 1.00
other combinations 70 (23) 0.99 (0.55, 1.79) 0.84 (0.52, 1.37) 0.92 (0.61, 1.40)
≥ 3 ≥ 6 110 (37) 1.35 (0.80, 2.28) 1.14 (0.73, 1.79) 1.43 (0.89, 2.29)
  1. ^ Crude ORs are unadjusted for covariates or offspring born to the same mother or father
  2. * ORs are unadjusted for covariates, but adjusted for offspring born to the same mother or father
  3. ** AORs are adjusted for covariates (Model 1 adjusted for year of offspring's birth; Models 2 and 3 adjusted for year of offspring's birth and paternal BMI as low and normal vs. high) and adjusted for offspring born to the same mother or father