Introduction: The first 1000 days of an infant’s life is a critical period of development, and presents a key window for understanding disease origins and maximising future health. The influence of the maternal antenatal environment in programming fetal development is increasingly recognised, however significant knowledge gaps remain regarding the influence of maternal health and lifestyle on infant growth beyond the neonatal period. This study investigated the impact of maternal cardiometabolic health and lifestyle on infant growth during the first year of life.
Methods: This sub-study of the longitudinal Microbiome Understanding in Maternity Study followed 92 mother-infant dyads throughout pregnancy until twelve months post-partum. Maternal anthropometrics and body composition were collected at each trimester (T). Diet was assessed using the Australian Eating Survey at T1 and T3, and diet quality (Australian Recommended Food Score) calculated. Physical activity was self-reported at T1, T2 and T3 using The International Physical Activity Questionnaire, and individually categorised as ‘inactive’, ‘minimally active’ or ‘highly active’. Infant anthropometrics were measured at birth, 6 weeks, 6 months and 12 months. Changes in weight, weight-for-age z-scoreand length-for-age z-score were calculated. Rapid weight gain (RWG) was defined as an increase in weight-for-age z-score of at least 0.67 between time points. Conditional weight gain (CWG) was calculated to account for the natural regression of infant growth to the mean, using standardised residuals of the change in weight-for-age z-score, controlling for birthweight, sex and age. Statistical analysis was conducted using IBM SPSS Statistics.
Results: Maternal T1 weight (p=0.032) and fat mass (p=0.024) were positively associated with infant CWG from 6 weeks-6 months, and maternal gestational weight gain was positively associated with infant weight z-score change (p=0.039), RWG (p=0.003) and CWG (p=0.044) from 6-12 months. Maternal T1 diet quality was positively associated with gains in infant length z-score from 0-6 weeks (p<0.001), 0-6 months (p<0.001) and 0-12 months (p=0.003). T1 energy intake from core foods was positively associated with infant growth from 0-12 months (weight z-score change p=0.020, length z-score change p=0.037, CWG p=0.028). Physical activity was positively associated with gains in infant weight z-score from 6-12 months (T2 p=0.011, T3 p=0.030).
Conclusions: Our results suggest that increased maternal adiposity and gestational weight gain and healthier lifestyle behaviours were associated with increased infant growth. Further investigation is required in larger cohorts with longer infant follow-up to confirm findings and investigate links with future health sequelae.