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

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

		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)

^ Crude ORs are unadjusted for covariates or offspring born to the same mother or father
* ORs are unadjusted for covariates, but adjusted for offspring born to the same mother or father
** 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

ISSN: 1476-069X