Poster Presentation ANZOS Annual Scientific Meeting 2021

Child and maternal determinants of infant rapid weight gain: a meta-analysis of seven Australian and New Zealand cohorts (#249)

Miaobing Zheng 1 , Kylie Hesketh 1 , Peter Vuillermin 2 , Jodie Dodd 3 , Li Ming Wen 4 , Louise Baur 4 , Rachael Taylor 5 , Rebecca Byrne 6 , Seema Mihrshahi 7 , Karen Campbell 1
  1. Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
  2. Barwon Health, Geelong, Victoria, Australia
  3. Discipline of Obstetrics and Gynaecology, The Robinson Research Institute, The University of Adelaide, Adelaide, South Australia, Australia
  4. School of Public Health and Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia
  5. Department of Medicine, University of Otago, Dunedin, New Zealand
  6. School of Exercise and Nutrition Sciences, Faculty of Health, Queensland University of Technology, Kelvin Grove, Queensland, Australia
  7. Department of Health Systems and Populations, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, New South Wales, Australia

Background/Aims: Despite the extensive research linking infant rapid weight gain (RWG) with later obesity risk, the examination of factors associated with RWG during infancy is scarce. This study examined the association between a broad range of child and maternal factors and RWG in the first year of life.

Methods: Data from seven Australian and New Zealand cohorts were used (INFANT, INFANT Extend, Barwon Infant Study, LIMIT, Healthy Beginnings, NOURISH, POI) (n=4534). Weight z-scores at birth and around one year of age were calculated using WHO growth charts.  Infant RWG was defined as a change in weight z-score≥0.67 from birth to age one year. Multivariable logistic regression was used to assess the child and maternal determinants of infant RWG in each study. Meta-analysis was conducted to obtain pooled effect sizes.

Results: Boys were more likely to experience RWG (OR 1.38 95%CI 1.19, 1.60) than girls. Higher birth weight in kg (OR 0.09, 95%CI 0.04, 0.20) and greater gestational age in weeks (OR 0.69, 95%CI 0.48, 0.98) were associated with lower RWG risk.  Children who were breastfed for≥ 6 months were less likely to experience RWG (OR 0.47, 95%CI 0.40, 0.50). Solid introduction after age 6 months was associated with lower RWG risk (0R 0.77, 95% 0.63, 0.94). In contrast, children of smoking mothers showed higher odds (OR 1.60, 95%CI 1.28, 2.01) of experiencing RWG than those of non-smoking mothers. No evidence of association was found for maternal age, education level, marital status, and pre-pregnancy BMI.

Conclusion: The current study contributes to the limited body of evidence on determinants and aetiology of RWG. Child sex, birth weight, gestational age, infant feeding and maternal smoking status were identified as significant determinants of infant RWG. The findings provide valuable insights for obesity prevention policy and practice regarding the key factors to target and intervene.