. Author manuscript; available in PMC: 2012 Nov 1.

Published in final edited form as: Breast Cancer Res Treat. 2011 May 20;130(1):273–279. doi: 10.1007/s10549-011-1582-3

Table 3.

Odds ratios (and 95% confidence intervals) for breast cancer by category of maternal weight gain in pregnancy, according to age at diagnosis and ER status of the tumor

Maternal weight gain in pregnancy	Age at diagnosis				ER status of tumor
Maternal weight gain in pregnancy	Cases <50 years		Cases ≥ 50 years		ER+ Cases		ER- Cases
Wt gain <10 lbs	19/69	0.95 (0.59–1.54)	9/69	0.93 (0.46–1.89)	15/69	0.95(0.55–1.63)	8/69	1.23 (0.57–2.63)
Wt gain 10–14 lbs	54/222	0.93 (0.69–1.27)	45/222	1.22 (0.83–1.80)	56/222	1.13 (0.82–1.56)	20/222	1.06 (0.62–1.79)
Wt gain 15–19 lbs	113/322	1.05 (0.83–1.34)	47/324	1.09 (0.75–1.61)	83/322	1.08 (0.81–1.43)	30/324	0.95 (0.60–1.51)
Wt gain 20–29 lbs	173/514	1.00 (ref)	64/514	1.00 (ref)	120/514	1.00 (ref)	50/514	1.00 (ref)
Wt gain 30–40 lbs	78/207	1.11 (0.85–1.45)	34/207	1.22 (0.80–1.86)	54/207	1.11(0.80–1.53)	29/207	1.54 (0.97–2.45)
Wt gain 40+ lbs	21/79	0.90 (0.57–1.42)	6/79	0.65 (0.28–1.49)	19/79	1.09 (0.66–1.78)	4/79	0.59 (0.21–1.65)
p-trend^*		0.69		0.56		0.99		0.56

Odds ratios are adjusted for birth year of nurse, cohort, family history of breast cancer in nurses' mother or sister (yes/no; as reported by nurse), maternal smoking during pregnancy (no, yes <25 cigs/day, yes >=25 cigs/day).

p-trend from model using the midpoint of each weight gain category as a continuous variable.