MedicalResearch.com Interview with:
Yeyi Zhu, PhD
IRTA Postdoctoral Fellow
Division of Intramural Population Health Research
Eunice Kennedy Shriver National Institute of Child Health and Human Development,
MedicalResearch: What is the background for this study? What are the main findings?
Dr. Zhu: Currently in the US, nearly two thirds of reproductive-aged women are overweight or obese. Moreover, the amount of weight gained during pregnancy can have immediate and long-lasting impacts on health of a woman and her infant. Previous evidence implicates that excessive gestational weight gain above the Institute of Medicine guidelines is related to high birthweight (>4000 g), a marker of intrauterine over-nutrition which may impose a greater risk of offspring’s obesity and metabolic diseases in later life.
Given that more than one third of children and adolescents are overweight or obese in the US, it is of great public health significance to improve our understanding of determinants and mediators of childhood obesity. The length of breast feeding and age at introduction of solid foods are infant feeding practices that are potentially modifiable in early life. We therefore examined whether birthweight and infant feeding practices, specifically length of breast feeding, mediate the relationship between maternal gestational weight gain and childhood growth in the National Children’s Study Formative Research in Anthropometry, a cross-sectional multi-ethnic study of 1387 mothers and their children aged 0-5.9 years in the US (2011-2012).
We illustrated that the intergenerational relationship between maternal gestational weight gain and early childhood growth (i.e., z scores for weight-for-age, weight-for-height, and body mass index-for-age) largely acts through birthweight rather than directly on childhood growth. Further, given the negative association of breastfeeding duration with childhood anthropometrics, longer length of breastfeeding suppressed the positive associations of gestational weight gain and birthweight with childhood growth. In addition, analysis by ethnicity revealed that these associations were only significant in non-Hispanic White and non-Hispanic Black participants as opposed to Hispanics and other ethnicities.
MedicalResearch: What should clinicians and patients take away from your report?
Dr. Zhu: Findings suggest that promoting longer breastfeeding duration may be a strategy for women who have gained a lot of weight in pregnancy and had high birthweight infants to mitigate offspring’s obesity risk. In addition, our findings reinforce the importance of promoting appropriate gestational weight gain and preventing high birthweight, which are positively associated with childhood anthropometrics as reported in our study and previously.
MedicalResearch: What recommendations do you have for future research as a result of this study?
Dr. Zhu: Due to the cross-sectional nature of our data, our ability to establish causal inferences was limited. Further investigation that can longitudinally examine the interplay among maternal gestational weight gain, child’s birthweight, and childhood growth/obesity is needed to confirm our findings. There is also a need to investigate the ethnic-specific pathways from maternal gestational weight gain to childhood growth trajectories.
J Epidemiol Community Health jech-2014-204794Published Online First: 13 February 2015 doi:10.1136/jech-2014-204794
MedicalResearch.com Interview with: Yeyi Zhu, PhD (2015). NIH Study Examines Links Between Breastfeeding Duration and Childhood Obesity