Table 4.

Weight retention at 18 months postpartum in relation to breast-feeding duration (n 27 187), Norwegian Mother and Child Cohort Study (MoBa)

	β	95 % CI	P value
Duration of breast-feeding†
All women‡
Full breast-feeding up to 6 months (kg/month)	−0·10	−0·17, −0·03	0·006
Partial breast-feeding up to 6 months (kg/month)	−0·01	−0·07, 0·05	0·73
Partial breast-feeding for 6–11 months, yes/no (kg)	0·01	−0·20, 0·21	0·97
Partial breast-feeding for 12–18 months, yes/no (kg)	−0·29	−0·42, −0·16	<0·001
Full breast-feeding × household income	−0·12	−0·19, −0·04	0·003
Stratified analyses
Full breast-feeding up to 6 months (kg/month)
Low income	−0·20	−0·30, −0·09	<0·001
High income	−0·11	−0·18, −0·04	<0·01

†Results from multivariate regression models. Both full and partial breast-feeding in the same model; all models adjusted for pre-pregnant BMI, pregnancy weight gain, maternal age and parity.

‡Interactions between income and education (respectively, 1 for lower levels/0 for higher levels) and full and partial breast-feeding were all tested. The only significant interaction was for full breast-feeding and household income.