Table 8. .

ORs by Fetal GSTT1 Genotype and Maternal Smoking Categories

Population, GSTT1 Genotype, and No. of Daily Cigarettes	Case	Control	OR	95% CI
DBS:
+/+ or +/−a:
0	113	223	Reference
1–9	34	61	1.10	.68–1.77
10–19	54	82	1.30	.86–1.96
20+	8	18	.88	.37–2.08
−/−b:
0	18	44	Reference
1–9	8	9	2.17	.72–6.52
10–19	12	7	4.19	1.42–12.36
20+	3	3	2.44	.45–13.27
Iowa:
+/+ or +/−c:
0	172	180	Reference
1–4	8	15	0.56	.23–1.35
5–14	22	14	1.64	.82–3.32
15+	24	14	1.79	.90–3.58
−/−d:
0	30	57	Reference
1–4	3	3	1.90	.36–10
5–14	6	2	5.70	1.83–29.99
15+	9	1	17.10	2.07–141.4

^aCochran-Armitage trend test Z=.83; P=.409.

^bCochran-Armitage trend test Z=2.56; P=.011.

^cCochran-Armitage trend test Z=1.85; P=.064.

^dCochran-Armitage trend test Z=3.87; P=.0001.