Table A5. .

Interaction between Fetal GSTT1 Genotypes and Maternal Smoking

Population and Phenotype	RR (unexpa)	95% CI of RR–	RR (expb)	95% CI of RR–	RR (interactionc)	95% CI of RR	χ2	P	Adjusted Pd
DBS:
Alle	.84	.48–1.46	2.34	1.12–4.91	2.79	1.11–7.01	4.9	.03f	.03
CPO	.87	.35–2.19	4.22	1.39–12.85	4.83	1.14–20.43	4.5	.03	.03
CL/P	.83	.44–1.55	1.97	.89–4.38	2.38	.86–6.55	2.8	.09	.12
Iowa triad:
Alle	.65	.37–1.15	4.54	1.20–17.15	7.03	1.67–28.98	8.7	.003f	.02
No anomaliesg	.60	.33–1.10	4.61	1.20–17.76	7.72	1.80–32.83	9.2	.002	.03
CLO	.48	.15–1.50	6.21	1.20–31.64	12.9	1.90–88.01	7.3	.007	.01
CPO	.63	.26–1.55	6.95	1.48–31.76	11.1	1.95–60.70	8.3	.004	.04
CL/P	.75	.39–1.41	3.33	.78–14.12	4.45	.94–21.43	3.8	.05	.13
DBS and Iowa triad:
Alle	.70	.47–.97	2.23	1.20–3.71	3.17	1.59–6.13	9.5	.002	<.001
No anomaliesg	.69	.45–.96	2.21	1.19–3.72	3.21	1.62–6.34	9.5	.002	<.001
CPO	.60	.37–1.19	4.25	1.51–7.33	7.13	1.88–13.41	11.4	<.001	<.001
CL/P	.79	.49–1.13	1.76	.91–3.17	2.23	1.08–4.81	3.7	.05	.03

^aRR of GSTT1-null genotype in nonsmoking mothers.

^bRR of GSTT1-null genotype in smoking mothers.

^cRR of the interaction effect between GSTT1-null genotype and maternal cigarette smoking.

^dAdjusted for vitamin and alcohol use.

^eIncludes data from all subjects with nonsyndromic OC.

^fThe combined P value by use of Fisher’s method is .0009, which remains significant after correction for multiple tests (see the “Material and Methods” section).

^gIncludes data from subjects without other minor anomalies.