Table 2.

Risk estimates for maternal and paternal cigarette smoking by case groupings

Maternal no. of cigarettes smoked/day
Paternal no. of cigarettes smoked/day			0		1–19
		*N	OR &95% CI	P-value	N*	OR &95% CI	P-value
Isolated	0	38	ref**		20	19.2 (6.2-59.5)	0.021
CL±P (n= 76)	1–19	7	0.45 (0.2-1.05)	0.254	11	6 (2.2-16.6)	0.005
Isolated CP	0	3	ref		4	48.7 (8-293)	0.041
(n= 29)	1–19	14	11.2 (3.1-40.3)	0.031	8	55.6 (12-256)	0.023

^*Number of case mothers/fathers in a given category. Number in parentheses is the number of control mothers/fathers.

^**Reference group