Co‐causation of reduced newborn size by maternal undernutrition,infections, and inflammation

More than 20 million babies are born with low birthweight annually. Small newborns have an increased risk for mortality, growth failure, and other adverse outcomes. Numerous antenatal risk factors for small newborn size have been identified, but individual interventions addressing them have not markedly improved the health outcomes of interest. We tested a hypothesis that in low‐income settings, newborn size is influenced jointly by multiple maternal exposures and characterized pathways associating these exposures with newborn size. This was a prospective cohort study of pregnant women and their offspring nested in an intervention trial in rural Malawi. We collected information on maternal and placental characteristics and used regression analyses, structural equation modelling, and random forest models to build pathway maps for direct and indirect associations between these characteristics and newborn weight‐for‐age Z‐score and length‐for‐age Z‐score. We used multiple imputation to infer values for any missing data. Among 1,179 pregnant women and their babies, newborn weight‐for‐age Z‐score was directly predicted by maternal primiparity, body mass index, and plasma alpha‐1‐acid glycoprotein concentration before 20 weeks of gestation, gestational weight gain, duration of pregnancy, placental weight, and newborn length‐for‐age Z‐score (p < .05). The latter 5 variables were interconnected and were predicted by several more distal determinants. In low‐income conditions like rural Malawi, maternal infections, inflammation, nutrition, and certain constitutional factors jointly influence newborn size. Because of this complex network, comprehensive interventions that concurrently address multiple adverse exposures are more likely to increase mean newborn size than focused interventions targeting only maternal nutrition or specific infections.     

Feeding effects on growth during infancy

OBJECTIVE: To examine the effects of formula, other milks, other liquids, cereals, and other solid foods on growth during infancy. STUDY DESIGN: Observational cohort study nested within a large (n=17,046), cluster-randomized trial. We compared growth [weight-for-age, length-for-age, and weight-for-length z scores (WAZ, LAZ, WLZ) and head circumference (HC)] during the intervals 1 to 3, 3 to 6, 6 to 9, and 9 to 12 months, using hierarchical multivariate regression to control for size at the beginning of each interval, maternal education, geographic region, and urban versus rural location. RESULTS: Mixed BF and formula/other milk were associated with significantly higher (versus breast milk only) LAZ at 1 to 3 months (+0.038 and +0.047, respectively). In the 3- to 6-month interval, mixed BF and formula/other milk led to significantly higher WAZ (+0.125 and +0.139) and LAZ (+0.081 and +0.075), whereas cereal intake was associated with large and highly significant reductions in both measures (-0.293 and -0.240) and in HC (-0.291 cm). Mixed BF and formula/other milk continued to have positive albeit smaller associations with WAZ and LAZ in the 6- to 9-month and 9- to 12-month intervals. CONCLUSIONS: Our results confirm the growth-accelerating effects of formula and other milks (versus breast milk) on weight and length gain throughout infancy, with a dose-response gradient and largest associations observed at 3 to 6 months.     

Feeding and growth of normal birth weight infants during the first year of life in Shanghai

Aim

This study aimed to explore the relationship between infant feeding practices and growth outcomes in the first 12 months of life.

Design

Investigators completed 262 questionnaires, which included infant feeding patterns, feeding environment, feeding beliefs/attitudes and caregivers' feeding behaviors through on-site face-to-face interviews with the main caregivers of infants at 12 months of age. The infant's weight and length at ages 6 and 12 months were measured.

Setting

The study was conducted in urban Shanghai, China.

Subjects

This study included 262 healthy normal birth weight full-term singleton 6-month-old infants and their main caregivers.

Results

Among 262 infants, 86 (32.82%) infants were overweight [BMI-for-age z scores (BAZ) > + 1] at 12 months. Compared with normal weight infants, the overweight infants had higher birth weights (P = 0.009). Furthermore, the overweight infants gained significantly more weight (P < 0.001) in the first year of life. In normal weight infants, caregivers worried more about infants being “underweight” and “eating less” (P < 0.001) whereas caregivers with overweight infants worried more about infants being “overweight” (P < 0.001). Consequently, the total score of caregivers' over-feeding behaviors was significantly higher in normal weight infants (P = 0.029). However, in overweight infants, the scores of “fed quickly within 10 min” (r = 0.223, P = 0.039) and “feeding was the best way to stop the infant's fussiness” (r = 0.285, P = 0.008) were positively correlated with BAZ.

Conclusions

Overweight in early life is associated with carelessness about excessive appetite and some particular infant feeding behaviors of caregivers in Shanghai.     

Newborn length predicts early infant linear growth retardation and disproportionately high weight gain in a low-income population

Background

Stunting is prevalent by the age of 6 months in the indigenous population of the Western Highlands of Guatemala.

Aim

The objective of this study was to determine the time course and predictors of linear growth failure and weight-for-age in early infancy.

Study design and subjects

One hundred and forty eight term newborns had measurements of length and weight in their homes, repeated at 3 and 6 months. Maternal measurements were also obtained.

Results

Mean ± SD length-for-age Z-score (LAZ) declined from newborn − 1.0 ± 1.01 to − 2.20 ± 1.05 and − 2.26 ± 1.01 at 3 and 6 months respectively. Stunting rates for newborn, 3 and 6 months were 47%, 53% and 56% respectively. A multiple regression model (R² = 0.64) demonstrated that the major predictor of LAZ at 3 months was newborn LAZ with the other predictors being newborn weight-for-age Z-score (WAZ), gender and maternal education ∗ maternal age interaction. Because WAZ remained essentially constant and LAZ declined during the same period, weight-for-length Z-score (WLZ) increased from − 0.44 to + 1.28 from birth to 3 months. The more severe the linear growth failure, the greater WAZ was in proportion to the LAZ.

Conclusion

The primary conclusion is that impaired fetal linear growth is the major predictor of early infant linear growth failure indicating that prevention needs to start with maternal interventions.     

Determinants of growth in HIV‐exposed and HIV‐uninfected infants in the Kabeho Study

HIV‐exposed and HIV‐uninfected (HEU) infants may be at increased risk of poor health and growth outcomes. We characterized infant growth trajectories in a cohort of HEU infants to identify factors associated with healthy growth. HIV‐positive women participating in prevention of mother‐to‐child HIV transmission programmes in Kigali, Rwanda, were followed until their infants were 2 years old. Infant anthropometrics were regularly collected. Latent class analysis was used to categorize infant growth trajectories. Multiple logistic regression was used to estimate the odds of infants belonging to each growth trajectory class. On average, this population of HEU infants had moderate linear growth faltering, but only modest faltering in weight, resulting in mean weight‐for‐length z‐score (WLZ) above the World Health Organization (WHO) median. Mean WLZ was 0.53, and mean length‐for‐age z‐score (LAZ) was ?1.14 over the first 2 years of life. We identified four unique WLZ trajectories and seven trajectories in LAZ. Low neonatal weight‐for‐age and a high rate of illness increased the likelihood that infants were in the lightest WLZ class. Shorter mothers were more likely to have infants with linear growth faltering. Female infants who were older at the end of exclusive breastfeeding were more likely to be in the second tallest LAZ class. In conclusion, the current WHO recommendations of Option B+ and extended breastfeeding may induce higher WLZ and lower LAZ early in infancy. However, there is considerable heterogeneity in growth patterns that is obscured by simply analysing average growth trends, necessitating the analysis of growth in subpopulations.