Mother and Infant Predictors of Rapid Infant Weight Gain

Growth trajectory of full-term small-for-gestational-age infants: a 3-year longitudinal study in China

OBJECTIVE

Small-for-gestational-age (SGA) infants are at risk of impaired growth and developmental outcomes, even for those who were born at full term. The growth trajectory of full-term SGA infants remains unknown. Therefore, this study aimed to evaluate the growth trajectory of full-term SGA infants from birth to 3 years old in East China.

METHODS

Full-term SGA infants were followed up from birth to 3 years old. The weight and length were measured at 3, 6, 12, 18, 24, 30 and 36 months. Rate of catch-up growth and rates of growth deviations including short stature, emaciation, underweight, overweight and obesity, were calculated at different time points. Latent class analysis was applied to describe growth trajectories from birth to 36 months.

RESULTS

A total of 816 full-term SGA infants were enrolled in this study and 303 had complete follow-up data at 3, 6, 12, 18, 24, 30 and 36 months. At 24 months, the rate of catch-up growth was 42.4% in girls and 48.6% in boys; while at 36 months, this rate was 43.3% in girls and 52.1% in boys. The latent class analysis identified two trajectories of weight and length in boys and girls. Girls showed different growth trajectories of weight since 12 months compared with boys.

CONCLUSIONS

Our study reported a relatively low rate of catch-up growth in full-term SGA infants and has identified different growth trajectories of length and weight in boys and girls. We call for attention from health professionals on the growth trajectory of full-term SGA infants to eventually promote their health potentials.

Prenatal oxidative stress and rapid infant weight gain

BACKGROUND AND OBJECTIVES

Infant weight patterns predict subsequent weight outcomes. Rapid infant weight gain, defined as a >0.67 increase in weight-for-age z-score (WAZ) between two time points in infancy, increases obesity risk. Higher oxidative stress, an imbalance between antioxidants and reactive oxygen species, has been associated with low birthweight and paradoxically also with later obesity. We hypothesized that prenatal oxidative stress may also be associated with rapid infant weight gain, an early weight pattern associated with future obesity.

METHODS

Within the NYU Children's Health and Environment Study prospective pregnancy cohort, we analyzed associations between prenatal lipid, protein, and DNA urinary oxidative stress biomarkers and infant weight data. Primary outcome was rapid infant weight gain (>0.67 increase in WAZ) between birth and later infancy at the 8 or 12 month visit. Secondary outcomes included: very rapid weight gain (>1.34 increase in WAZ), low (<2500 g) or high (≥4000 g) birthweight, and low (< -1 WAZ) or high (>1 WAZ) 12 month weight.

RESULTS

Pregnant participants consented to the postnatal study (n = 541); 425 participants had weight data both at birth and in later infancy. In an adjusted binary model, prenatal 8-iso-PGF2α, a lipid oxidative stress biomarker, was associated with rapid infant weight gain (aOR 1.44; 95% CI: 1.16, 1.78, p = 0.001). In a multinomial model using ≤0.67 change in WAZ as a reference group, 8-iso-PGF2α was associated with rapid infant weight gain (defined as >0.67 but ≤1.34 WAZ; aOR 1.57, 95% CI: 1.19, 2.05, p = 0.001) and very rapid infant weight gain (defined as >1.34 WAZ; aOR 1.33; 95% CI: 1.02, 1.72, p < 0.05) Secondary analyses detected associations between 8-iso-PGF2α and low birthweight outcomes.

CONCLUSIONS

We found an association between 8-iso-PGF2α, a lipid prenatal oxidative stress biomarker, and rapid infant weight gain, expanding our understanding of the developmental origins of obesity and cardiometabolic disease.

Capacity for Regulation of Energy Intake in Infancy

Importance

The capacity for regulation of energy intake (REI) to match energy needs is thought to contribute to differences in weight gain, and preventing excess infant weight gain is a priority.

Objective

To determine capacity for REI across infancy.

Design, Setting, and Participants

For this cohort study, a convenience sample of mother-infant dyads was recruited from the community in Michigan between 2015 and 2019. Inclusion criteria were healthy, full-term infants with weight appropriate for gestational age; biological mothers who were 18 years or older, English speaking, and a legal and custodial guardian; and infant having had consumed 2 oz or more in 1 feeding from an artificial nipple at least once per week. Infants were followed in the home setting with staff support for up to 12 months.

Interventions

Mother-infant dyads participated at infant age 1, 2.5, 5, 7, 10, and 12 months. In the intervention condition, mothers offered a feeding every hour for 6 hours. In the control condition, mothers fed infants as they typically would for 6 hours. Intake was recorded and kilocalories calculated.

Main Outcomes and Measures

Capacity for REI was indexed as the difference in intake in kilocalories per kilogram of body weight (intervention minus control condition); a value of 0 indicated perfect REI. Maternal and infant characteristics were obtained by questionnaire, and anthropometry was measured. Using multiple imputation, the intercept and slope for difference in kilocalories per kilogram across the 6 age points were estimated using mixed models accounting for repeated measures within participants. Statistical analyses were conducted between September 2021 and February 2023.

Results

The sample included 175 infants (87 [49.71%] female, 88 [50.29%] male; 494 pairs of intervention and control conditions and 4630 feedings). The mean (SD) 12-month weight-for-age z score was 0.1 (0.8). Mean (SD) gestational age as 39.55 (1.05) weeks, and mean (SD) birth weight was 3.43 (0.41) kg. Mean (SD) breastfeeding duration for those who reported stopping by 12 months was 17.83 (12.03) weeks. As designed, the intervention (compared with control) condition included more feedings at shorter intervals. After collapsing the data across age points in a mixed model accounting for repeated measures within participants, the REI estimate at 1 month differed from 0. On average, infants ate 5.21 kcal/kg (95% CI, 2.89-7.54 kcal/kg) more in the frequent feeding intervention condition than in the ad lib feeding control condition. This difference did not significantly change over 12 months of infancy (REI slope = -0.01 kcal/kg per month; 95% CI, -0.02 to 0.03 kcal/kg per month).

Conclusions and Relevance

The study's findings suggested that, on average, when offered more frequent feedings, healthy, full-term infants may overeat. The results provide support for responsive feeding as a strategy for preventing excess infant weight gain.

The care of infants with rapid weight gain: Should we be doing more?

Rapid weight gain (RWG) during infancy is a known risk factor for later childhood obesity. It can be measured using a range of definitions across various time periods in the first 2 years of life. In recent years, some early childhood obesity prevention trials have included a focus on preventing RWG during infancy, with modest success. Overall, RWG during infancy remains common, yet little work has examined whether infants with this growth pattern should receive additional care when it is identified in health-care settings. In this viewpoint, we contend that RWG during infancy should be routinely screened for in health-care settings, and when identified, viewed as an opportunity for health-care professionals to instigate non-stigmatising discussions with families about RWG and general healthy practices for their infants. If families wish to engage, we suggest that six topics from early life obesity prevention studies (breastfeeding, formula feeding, complementary feeding, sleep, responsive parenting, and education around growth charts and monitoring) could form the foundations of conversations to help them establish and maintain healthy habits to support their infant's health and well-being and potentially lower the risk of later obesity. However, further work is needed to develop definitive guidelines in this area, and to address other gaps in the literature, such as the current lack of a standardised definition for RWG during infancy and a clear understanding of the time points over which it should be measured.

Infant appetite and weight gain in early infancy: Moderating effects of controlling feeding styles

Excessive infant weight gain is a strong predictor of later obesity. While controlling feeding has been linked to negative weight outcomes, research has not considered associations between infant appetite and maternal feeding simultaneously in relation to infant weight. This longitudinal study examined infant food responsiveness and slowness in eating as predictors of infant weight outcomes and tested controlling feeding styles (restrictive and pressuring) as moderators. Data came from a diverse sample of mothers and their infants participating in an ongoing longitudinal study. Mothers (n = 159) reported infant appetite and feeding styles at 2 postnatal timepoints (2-month visits and 6-month visits). The infant weight outcomes included change in weight-for-age z-scores (WAZ-change) and rapid weight gain (RIWG; WAZ-change ≥ 0.67 SD) from birth to the second postnatal visit. Data were analyzed using hierarchical multiple and logistic regressions, controlling for birthweight, gestational age, maternal race/ethnicity, feeding mode, and residing with an intimate partner. Over 25% of infants exhibited RIWG. Greater infant food responsiveness predicted both greater infant weight gain and RIWG status. Infant food responsiveness and slowness in eating interacted with controlling feeding styles in a unique way. Infants with higher food responsiveness whose mothers were less restrictive had greater weight gain (b = 0.61, p < 0.001) and increased probability of RIWG (b = 2.71, p < 0.01) than infants with more restrictive mothers. Higher slowness in eating was associated with a lower RIWG probability among infants of mothers with lower pressuring feeding (b = -1.86, p < 0.05). For infants with a large appetite, some level of restrictive feeding may be beneficial for preventing excessive weight gain while pressuring may exacerbate the positive association between faster eating and RIWG.

Maternal Stress and Excessive Weight Gain in Infancy

Rapid weight gain in infancy increases the risk of developing obesity early in life and contributes significantly to racial and ethnic disparities in childhood obesity. While maternal perceived stress is associated with childhood obesity, little is known about the impact it has on infant weight gain. Therefore, this study explores the impact of maternal perceived stress on change in weight-for-length (WFL) z-scores and the risk of rapid weight gain in infancy. We conducted a secondary data analysis of the longitudinal Nurture birth cohort (n = 666). Most mothers in the cohort were non-Hispanic/Latinx Black (71.6%). About one-half of mothers had a body mass index (BMI) greater than 25 prior to pregnancy, were unemployed, and had a low income. Most infants in the cohort were born full-term and were of normal weight. Data were collected at 3-, 6-, 9-, and 12-months postpartum. At each assessment, mothers completed the Cohen’s Perceived Stress Scale (PSS), and research assistants weighed and measured each infant. Tertiles were used to compare mothers with high and low perceived stress. A mixed model analysis of repeated measures assessed the associations between baseline perceived stress and the change in infant WFL z-scores over time. Log-binomial models assessed the association between baseline perceived stress and rapid weight gain, defined as a change in WFL z-score > 0.67 standard deviations from three to twelve months. Just under one-half of the infants (47%) experienced rapid weight gain between three and twelve months of age. Birthweight for gestational age (RR = 1.18, 95% CI = 1.08−1.29, p-value = 0.004), gestational age at birth (RR = 1.07, 95% CI = 1.01−1.14, p-value = 0.031), and weeks breastfed (0.99, 95% CI 0.99−1.00, p-value 0.044) were associated with risk of rapid weight gain in unadjusted analyses. WFL z-scores increased significantly over time, with no effect of perceived stress on change in WFL z-score or risk of rapid weight gain. Rapid weight gain in infancy was prevalent in this sample of predominately Black infants in the Southeastern US. We did not find evidence to support the hypothesis that maternal perceived stress influenced the risk of rapid weight gain. More work is needed to identify and assess the risk factors for rapid weight gain in infancy and to understand the role that maternal stress plays in the risk of childhood obesity so that prevention efforts can be targeted.

Age of Bottle Cessation and BMI-for-Age Percentile among Children Aged Thirty-Six Months Participating in WIC

Background: Children's age at bottle weaning typically ranges from 12 to 24 months. The recommended age of bottle weaning varies. The American Academy of Pediatrics recommends weaning by 12 months; The American Academy of Pediatric Dentistry recommends 12-15 months; The US Department of Agriculture recommends 18 months. Prolonged bottle use is associated with dental caries, iron-deficiency anemia, and child overweight or obesity. We examined factors associated with age of bottle cessation, and the association between age of bottle cessation and BMI-for-age percentile at age 36 months among Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) participants. Methods: Data were from the WIC Infant and Toddler Feeding Practices Study-2 (ITFPS-2). The ITFPS-2, a longitudinal study of WIC participants (mothers and their children) began in 2013. We used Cox proportional hazards models to identify factors associated with bottle cessation and multivariate linear regression to examine the association between age of bottle cessation and BMI. Results: About 34% of children used a bottle longer than 12 months, and 13% longer than 18 months. Bottle cessation at older ages was associated with Hispanic ethnicity, multiparity, low income, low education, higher caregiver weight, and not initiating breastfeeding. The adjusted children's BMI-for-age percentile at age 36 months increased by 0.47 for each additional month of bottle use. Conclusion: Prolonged bottle use was associated with increased children's BMI-for-age percentile. Future research is warranted to determine the optimal age to recommend bottle cessation for WIC participants.

Associations between KCNQ1 and ITIH4 gene polymorphisms and infant weight gain in early life

BACKGROUND

An earlier meta-analysis of genome-wide association studies in Asian populations detected five novel body mass index-associated single-nucleotide polymorphisms (SNPs), including potassium voltage-gated channel subfamily Q member 1 (KCNQ1) (rs2237892), ALDH2/MYL2 (rs671, rs12229654), ITIH4 (rs2535633), and NT5C2 (rs11191580). Whether these SNPs take effect in early life, for example, affect infant rapid weight gain (RWG), is unclear.

METHODS

We obtained genomic DNA from 460 term infants with normal birth weight. RWG was defined as the change of weight-for-age standardized Z-score, calculated according to the Children Growth Standard released by the World Health Organization, from birth to 3 months of age >0.67. Using genetic models, associations between the candidate SNPs and infant RWG were examined, along with the interaction between the SNPs and the potential risk factors.

RESULTS

RWG was presented in 225 of 460 infants. SNP rs2535633 and rs2237892 were associated with the risk of RWG. Both additive and multiplicative interaction effects were found between infant delivery mode and rs2237892. The negative association between the rs2237892 T allele and infant RWG was only observed in vaginally delivered infants.

CONCLUSIONS

Obesity-related loci rs2535633 and rs2237892 are associated with infant RWG in the first 3 months of infancy. The relationship between rs2237892 and infant RGW might be moderated by cesarean delivery.

IMPACT

Genetic predisposition is an essential aspect to understand infant weight gain. Obesity-related SNPs, rs2535633 and rs2237892, are associated with RWG in very early years of life. The negative association between rs2237892 T allele and RWG is only observed in infants delivered vaginally instead of cesarean section.

Associations between infant growth and pubertal onset timing in a multiethnic prospective cohort of girls

Background

Early puberty increases risk of adverse health conditions throughout the life course. US girls are experiencing earlier puberty without clear reasons. Studies suggest early life factors, such as infant growth, may influence pubertal timing. We assessed the associations between infant growth and onset of breast development (thelarche), pubic hair development (pubarche), and menarche in girls.

Methods

A prospective cohort of girls born at a Kaiser Permanente Northern California medical facility in 2005–11 was used. Weight-for-age z-scores were calculated at birth and 24 months. Difference in z-scores greater than 0.67 represent rapid “catch-up” growth, less than -0.67 represent delayed “catch-down” growth, and between -0.67 and 0.67 represent “normal” growth. Pubertal onset was measured using clinician-assessed sexual maturity ratings (SMRs) and defined as the age at transition from SMR 1 to SMR 2 + for both thelarche and pubarche. SMR data was collected through June 2020. Menarche was analyzed as a secondary outcome. Weibull and modified Poisson regression models were used. Models were adjusted for potential confounders.

Results

There were 15,196 girls included in the study. Approximately 30.2% experienced catch-up growth, 25.8% experienced catch-down growth, and 44% had normal growth. Girls with catch-up growth had increased risk of earlier thelarche (hazard ratio = 1.26, 95% confidence interval (CI): 1.18, 1.35), pubarche (1.38, 95% CI: 1.28, 1.48), and menarche (< 12y, relative risk = 1.52, 95% CI: 1.36, 1.69) compared to those with normal growth, after adjusting for covariates. These associations were partially mediated by childhood body mass index. Catch-down growth was associated with later pubertal onset.

Conclusions

Girls who experience infant catch-up growth have higher risk of earlier pubertal development compared to girls with normal growth and the associations are partially explained by childhood obesity. This information may help clinicians to monitor girls who are at high risk of developing earlier.

Factors Associated with the Initiation of Added Sugar among Low-Income Young Children Participating in the Special Supplemental Nutrition Program for Women, Infants, and Children in the US

Added sugar intake at a young age is associated with chronic diseases including cardiovascular diseases, asthma, elevated blood pressure, and overweight. The Dietary Guidelines for Americans 2020–2025 and the American Heart Association recommend delaying the introduction of added sugar until age 2. The aims of this study were to identify the timing of added sugar initiation; factors associated with added sugar initiation; and the top five added sugar foods and beverages consumed by infants and children at three age ranges (<7 months, 8–13 months, and 14–24 months). Data were from the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) Infant and Toddler Feeding Practices Study-2, a longitudinal, national population of WIC participants enrolled in WIC eligible clinics (n = 3835). The Cox proportional hazards model was used to examine the factors associated with introducing added sugar. About 25% of children were given added sugar at or before 7 months. Contributing factors were caregivers’ race/ethnicity, education, employment, weight status, parity, child sex, and premature birth (all p < 0.05). The top added sugar foods consumed between 1–24 months were cereal, crackers, apple sauce, dessert, yogurt, sweetened beverages, syrup and preserves, and cookies. Further research to examine the impact of early initiation of added sugar on health outcomes and taste preferences is warranted.

What Links Maternal Prepregnancy BMI to Early Childhood BMI: A Serial Mediation Analysis

OBJECTIVE

The aim of this study was to explore the potential impact of maternal gestational weight gain (GWG), infant birth weight, and postnatal weight change (ΔWAZ) on the relationship between maternal prepregnancy BMI (ppBMI) and childhood BMI.

METHODS

This retrospective cohort study analyzed a data set from Wuhan, China. The mediation effect of targeted mediators on the association between maternal BMI and childhood BMI at the age of 2 years was analyzed.

RESULTS

In the mediation model comprising maternal GWG, infant birth weight, and the first-6-month ΔWAZ as mediators of the association between ppBMI and children's BMI, the per unit increase in ppBMI resulted in a 0.01-kg/m² increase in children's BMI, through all three mediators. For the model comprising infant birth weight and the first-6-month ΔWAZ as mediators but maternal GWG as a moderator, the indirect effects of the first-6-month ΔWAZ on the relationship between ppBMI and childhood BMI was 0.0018 higher when maternal GWG increased from average values to 1 SD above the average values.

CONCLUSIONS

Maternal GWG, infant birth weight, and the first-6-month ΔWAZ mediated the effects of maternal ppBMI on children's BMI. Interventions targeting these factors can mitigate the risk of childhood obesity.

Nutrition- and feeding practice-related risk factors for rapid weight gain during the first year of life: a population-based birth cohort study

Background

Rapid weight gain (RWG) during infancy increases the risk of excess weight later in life. Nutrition- and feeding practices associated with RWG need to be further examined. The present study aimed to examine nutrition- and feeding practice-related risk factors for RWG during the first year of life.

Methods

A population-based longitudinal birth cohort study of 1780 infants, classified as having RWG or non-RWG during 0–3-4, 0–6 and 6–12 months. RWG was defined as a change > 0.67 in weight standard deviation scores. Associations between nutrition- and feeding practice-related factors and RWG were examined with logistic regression models.

Results

Of the participating infants, 47% had RWG during 0–3-4 months, 46% during 0–6 months and 8% during 6–12 months. In the fully adjusted models, bottle-feeding at birth and at 3–4 months and nighttime meals containing formula milk were positively associated with RWG during 0–3-4 months (p < 0.05 for all). Breastfeeding at 3–4 months and nighttime meals containing breast milk were negatively associated with RWG during this period (p < 0.001). Bottle-feeding at birth, 3–4 and 6 months and nighttime meals containing formula milk at 3–4 months were positively associated with RWG during 0–6 months (p < 0.01 for all). Breastfeeding at 3–4 and 6 months was negatively associated with RWG (p < 0.01). During 6–12 months, only bottle-feeding at 3–4 months was positively associated with RWG (p < 0.05).

Conclusions

RWG was more common during the first 6 months of life and bottle-feeding and formula milk given at night were risk factors for RWG during this period.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12887-020-02391-4.