The Association Between Maternal Adiposity and Breastfeeding Initiation and Duration: Evidence from the Southampton Women’s Survey

Most mothers in the UK are not meeting the breastfeeding recommendations set by the World Health Organisation (WHO, Breastfeeding - Recommendations. https://www.who.int/health-topics/breastfeeding#tab=tab_2 , 2023). Maternal obesity has variably been associated with lower initiation and shorter duration of breastfeeding, but few studies have examined the impact of maternal adiposity estimated from skinfold thicknesses. To investigate the relationship between maternal adiposity and breastfeeding initiation and duration. Data from 2,873 mother-offspring pairs in the Southampton Women’s Survey (SWS) mother-offspring cohort study were used to assess the relationship between a mother’s adiposity and breastfeeding initiation and duration. The exposure variables were body mass index (BMI) and body fat percentage, calculated from 4-site skinfold thickness measurements measured prior to conception. The outcome variables were breastfeeding initiation and duration. All analyses were adjusted for confounders identified using a Directed Acyclic Graph. After adjustment for confounders, no associations were found between maternal BMI (RR 0.99 per 5 kg/m2, 95% CI 0.97, 1.01) or body fat percentage (RR 0.99 per 5%, 95% CI 0.97, 1.00) and initiation of breastfeeding. After adjustment for confounders, amongst women who initiated breastfeeding, higher maternal BMI (β −0.09 SDs per 5 kg/m2, 95% CI −0.13, −0.04) and body fat percentage (β −0.10 SDs per 5%, 95% CI −0.16, −0.04) were associated with shorter breastfeeding duration. In this study maternal adiposity had little impact on breastfeeding initiation but higher maternal adiposity was associated with shorter breastfeeding duration. This study suggests that more support should be given to mothers with overweight and obesity to promote longer duration of breastfeeding. Currently, the evidence base surrounding this topic is conflicted. Some evidence suggests there is no association between maternal adiposity and breastfeeding, whilst other studies suggest that there is an association between maternal adiposity and breastfeeding. One possible explanation for the discrepancy is related to multiple adiposity measures used across the evidence base. This study uses a large mother-offspring cohort study based in England and is one of the few to recruit women prior to pregnancy. Two of the most commonly used methods for measuring adiposity were used to test for an association, addressing one of the current challenges within this topic area.