Table 2.

Odds Ratios for Breast Cancer by Tertile of Human Chorionic Gonadotropin and α-Fetoprotein Concentrations in Pregnancy, Northern Sweden Maternity Cohort, 1975–2001

	Tertile											P-Trend
	1			2				3
	OR	No. of Cases	No. of Controls	OR	95% CI	No. of Cases	No. of Controls	OR	95% CI	No. of Cases	No. of Controls
	Human Chorionic Gonadotropina
All women	1.00	63	98	1.03	0.63, 1.69	61	98	0.86	0.52, 1.42	49	98	0.54
Age at sampling, years
<30	1.00	30	45	0.92	0.44, 1.92	27	45	0.77	0.37, 1.61	22	45	0.49
≥30	1.00	31	53	1.19	0.63, 2.24	36	53	0.91	0.46, 1.81	27	53	0.84
Parity
Primiparous	1.00	35	44	0.68	0.32, 1.44	21	44	0.68	0.33, 1.41	22	45	0.29
Multiparous	1.00	34	53	0.817	0.46, 1.66	31	54	0.92	0.48, 1.75	30	54	0.78
Lag time to diagnosis, yearsb
<14	1.00	21	47	2.20	0.95, 5.10	35	48	1.67	0.72, 3.86	26	48	0.25
≥14	1.00	41	50	0.58	0.30, 1.15	27	50	0.53	0.27, 1.03	23	51	0.06
Age at cancer diagnosis, years
<45	1.00	31	50	1.25	0.63, 2.46	33	50	0.82	0.40, 1.70	24	51	0.66
≥45	1.00	34	47	0.71	0.35, 1.44	26	48	0.72	0.36, 1.44	25	48	0.36
Nonsmoker at blood donation	1.00	38	43	0.68	0.33, 1.38	25	43	0.73	0.37, 1.44	26	44	0.33
	α-Fetoprotein
Full data set	1.00	67	116	1.08	0.67, 1.73	73	116	0.91	0.55, 1.50	64	117	0.63
Restricted datac	1.00	54	99	1.21	0.75, 1.95	66	99	0.96	0.58, 1.58	54	99	0.80

Abbreviations: CI, confidence interval; OR, odds ratio.

^aAll models for human chorionic gonadotropin were adjusted for smoking.

^bTest for homogeneity of results below and above the median lag time to cancer diagnosis: P = 0.10.

^cWomen who donated blood before January 1, 1988 (174 cases and 297 controls).