Maternal antenatal health and infant growth outcomes: a Microbiome Understanding in Maternity Study.

The influence of the maternal antenatal environment on infant growth and development beyond the neonatal period is not well understood. This study investigated associations between maternal cardiometabolic health and lifestyle on infant growth during the first year of life. This sub-study of the longitudinal Microbiome Understanding in Maternity Study included 87 mother-infant dyads. Maternal anthropometrics were collected at each trimester. Lifestyle was assessed through the Australian Eating Survey (Trimester T1 and T3) and International Physical Activity Questionnaire (T1, T2 and T3). Infant anthropometrics were measured at birth, 6 weeks, 6 months and 12 months. Changes in weight, weight-for-age z-score, length-for-age z-score, rapid weight gain and conditional weight gain (CWG) were determined. Multiple linear regression was used to assess associations between maternal parameters and infant growth, adjusting for common confounders. Maternal T1 weight (CWG: p = 0.03), T3 weight (CWG: p = 0.03) and GWG (weight z-score change: p = 0.031) were positively associated with increased infant growth from 0 to 6 months. Greater maternal fat mass was associated with increased CWG (p = 0.042) from 6 weeks to 6 months. Higher quality maternal T1 diet was associated with increased infant growth (weight z-score change: p = 0.022, CWG: p = 0.013) from 0 to 12 months. Increased maternal physical activity was associated with increased CWG (p = 0.022) and length z-score change (p = 0.024) from 0 to 12 months in T1, and increased CWG from 6 to 12 months in T2 (p = 0.014) and T3 (p = 0.047). Markers of maternal cardiometabolic health risk and healthier lifestyle were associated with increased infant growth. Further investigation is required to confirm findings and investigate links with future health sequelae.