How is pregnancy‐related weight changes and breastfeeding related to long‐term maternal weight and waist circumference? A path analysis

Abstract

Pregnancy is a potential risk factor for excessive weight gain and may lead to long‐term maternal weight gain. This study examined how breastfeeding, gestational weight gain and postpartum weight changes were related to weight and waist circumference for given body mass index 7 y after birth. Also, we distinguish the direct effect from the one mediated through weight changes on the pathway. Women (n=23,701) from the Danish National Birth Cohort with singleton births and no birth during follow‐up were included. Information on anthropometry, breastfeeding, and covariates was obtained from interviews conducted at pregnancy wk 16, at mo 6 and 18 postpartum, and from a web‐based‐survey 7 y after birth. Using path analysis, we assessed the direct, indirect, and total effect. Gestational weight gain was positively associated with long‐term weight; 87 % of the effect was mediated through increased postpartum weight. Postpartum weight changes were highly associated with both outcomes and 1kg increase in weight retention at 6 mo corresponded to an increase of 0.5kg at 7 y. For both outcomes, breastfeeding duration showed an inverse association. It was strongest for waist circumference, where 97% of the effect was direct and not mediated through postpartum weight loss. These data suggest that breastfeeding has a beneficial effect on fat distribution. Weight changes in early motherhood are important for long‐term weight gain.