Postnatal growth of preterm infants during the first two years of life: catch-up growth accompanied by risk of overweight

Inadequate linear catch-up growth in children born small for gestational age: Influencing factors and underlying mechanisms

A minority of children born small for gestational age (SGA) may experience catch-up growth failure and remain short in adulthood. However, the underlying causes and mechanisms of this phenomenon are not yet fully comprehended. We reviewed the present state of research concerning the growth hormone-insulin-like growth factor axis and growth plate in SGA children who fail to achieve catch-up growth. Additionally, we explored the factors influencing catch-up growth in SGA children and potential molecular mechanisms involved. Furthermore, we considered the potential benefits of supplementary nutrition, specific dietary patterns, probiotics and drug therapy in facilitating catch-up growth.

Growth patterns of preterm and small for gestational age children during the first 10 years of life

Background

Preterm and small for gestational age (SGA) remain significant public health concerns worldwide. Yet limited evidence exists on their growth patterns during childhood from low-or middle-income countries.

Objectives

We investigated the postnatal growth patterns of preterm and SGA compared to term appropriate for gestational age (AGA) children from birth to 10-11y, and examined the impact of birth status on child nutritional status during the school age years.

Methods

Children born to women who participated in a double-blinded randomized controlled trial of preconception micronutrient supplementation in Vietnam were classified into three groups: preterm AGA (n = 130), full-term SGA (n = 165) and full-term AGA (n = 1,072). Anthropometric data (weight and height) were collected prospectively at birth, 3, 6, 12, 18, 24 months and at 6-7 and 10-11y. We used ANOVA and multiple regression models to examine the differences in growth patterns from birth to 10-11y as well as child undernutrition and overnutrition by birth status.

Results

Children who were born preterm exhibited rapid postnatal growth, but still had lower HAZ at 1y and 2y and showed catch up to the AGA group at 6y. Compared to those born AGA, SGA infants had higher risk of thinness (BMIZ < -2) at 2y and 6y (adjusted Odds Ratio, AOR [95% CI] 2.5 [1.0, 6.1] and 2.6 [1.4, 4.6], respectively); this risk reduced at 10-11y (1.6 [0.9, 2.8]). The risk of stunting (HAZ < -2) was also 2.4 [1.5, 3.8] and 2.3 times [1.2, 4.1] higher in SGA than AGA group at ages 2y and 6-7y, respectively, with no differences at 10y. Although preterm children had higher rates of thinness and stunting at 2y compared to AGA children, these differences were not statistically significant. No associations were found between preterm or SGA and overweight /obesity at age 10-11y.

Conclusion

Children who were born term-SGA continued to demonstrate deficits in weight and height during childhood whereas those born preterm showed catch-up growth by age 6-7y. Additional efforts to reduce the burden of these conditions are needed, particularly during school-age and early adolescents when children are exposed to challenging environments and have higher demands for nutrition.

[Longitudinal study on catch-up growth in preterm infants with small for gestational age at corrected ages 0-24 months]

OBJECTIVES

To understand the growth and development status and differences between small for gestational age (SGA) and appropriate for gestational age (AGA) preterm infants during corrected ages 0-24 months, and to provide a basis for early health interventions for preterm infants.

METHODS

A retrospective study was conducted, selecting 824 preterm infants who received regular health care at the Guangzhou Women and Children's Medical Center from July 2019 to July 2022, including 144 SGA and 680 AGA infants. The growth data of SGA and AGA groups at birth and corrected ages 0-24 months were analyzed and compared.

RESULTS

The SGA group had significantly lower weight and length than the AGA group at corrected ages 0-18 months (P<0.05), while there were no significant differences between the two groups at corrected age 24 months (P>0.05). At corrected age 24 months, 85% (34/40) of SGA and 79% (74/94) of AGA preterm infants achieved catch-up growth. Stratified analysis by gestational age showed that there were significant differences in weight and length at corrected ages 0-9 months between the SGA subgroup with gestational age <34 weeks and the AGA subgroups with gestational age <34 weeks and 34 weeks (P<0.05). In addition, the weight and length of the SGA subgroup with gestational age 34 weeks showed significant differences compared to the AGA subgroups with gestational age <34 weeks and 34 weeks at corrected ages 0-18 months and corrected ages 0-12 months, respectively (P<0.05). Catch-up growth for SGA infants with gestational age <34 weeks and 34 weeks mainly occurred at corrected ages 0-12 months and corrected ages 0-18 months, respectively.

CONCLUSIONS

SGA infants exhibit delayed early-life physical growth compared to AGA infants, but can achieve a higher proportion of catch-up growth by corrected age 24 months than AGA infants. Catch-up growth can be achieved earlier in SGA infants with a gestational age of <34 weeks compared to those with 34 weeks.

Maternal weight, blood lipids, and the offspring weight trajectories during infancy and early childhood in twin pregnancies

BACKGROUND

The intrauterine environment has a profound and long-lasting influence on the health of the offspring. However, its impact on the postnatal catch-up growth of twin children remains unclarified. Therefore, this study aimed to explore the maternal factors in pregnancy associated with twin offspring growth.

METHODS

This study included 3142 live twin children born to 1571 mothers from the Beijing Birth Cohort Study conducted from 2016 to 2021 in Beijing, China. Original and corrected weight-for-age standard deviation scores of the twin offspring from birth to 36 months of age were calculated according to the World Health Organization Child Growth Standards. The corresponding weight trajectories were identified by the latent trajectory model. Maternal factors in pregnancy associated with the weight trajectories of the twin offspring were examined after adjustment for potential confounders.

RESULTS

Five weight trajectories of the twin children were identified, with 4.9% (154/3142) exhibiting insufficient catch-up growth, 30.6% (961/3142), and 46.8% (1469/3142) showing adequate catch-up growth from different birth weights, and 15.0% (472/3142) and 2.7% (86/3142) showing various degrees of excessive catch-up growth. Maternal short stature [adjusted odds ratio (OR) = 0.691, 95% confidence interval (CI) = 0.563-0.848, P = 0.0004] and lower total gestational weight gain (GWG) (adjusted OR = 0.774, 95% CI = 0.616-0.972, P = 0.03) were associated with insufficient catch-up growth of the offspring. Maternal stature (adjusted OR = 1.331, 95% CI = 1.168-1.518, P < 0.001), higher pre-pregnancy body mass index (BMI) (adjusted OR = 1.230, 95% CI = 1.090-1.387, P < 0.001), total GWG (adjusted OR = 1.207, 95% CI = 1.068-1.364, P = 0.002), GWG rate (adjusted OR = 1.165, 95% CI = 1.027-1.321, P = 0.02), total cholesterol (TC) (adjusted OR = 1.150, 95% CI = 1.018-1.300, P = 0.03) and low-density lipoprotein-cholesterol (LDL-C) (adjusted OR = 1.177, 95% CI = 1.041-1.330) in early pregnancy were associated with excessive growth of the offspring. The pattern of weight trajectories was similar between monochorionic and dichorionic twins. Maternal height, pre-pregnancy BMI, GWG, TC and LDL-C in early pregnancy were positively associated with excess growth in dichorionic twins, yet a similar association was observed only between maternal height and postnatal growth in monochorionic twins.

CONCLUSION

This study identified the effect of maternal stature, weight status, and blood lipid profiles during pregnancy on postnatal weight trajectories of the twin offspring, thereby providing a basis for twin pregnancy management to improve the long-term health of the offspring.

[Research hotspots in post-discharge follow-up management of preterm infants]

Preterm infants, especially those born extremely or very prematurely, are at high risk for growth retardation and neurodevelopmental disorders. Regular follow-up after discharge, early intervention, and timely catch-up growth are important guarantees for improving the quality of life of preterm infants and improving the quality of the population. This article provides an overview of the research hotspots in follow-up management of preterm infants after discharge over the past two years, including follow-up modes, nutritional metabolism and body composition follow-up, growth pattern follow-up, neurodevelopmental follow-up, early intervention, etc., in order to provide clinical guidance and research ideas for domestic peers.

The trajectories of physical growth in 4 months postnatal corrected age among preterm infants discharged from neonatal intensive care units and associated factors: A prospective study

Objectives

Growth retardation is a risk for premature infants. In addition to demographic and perinatal factors, preterm infants' physical growth may be affected by neonatal intensive care unit (NICU) stress, maternal postpartum depression, and mother-infant interaction. This study aimed to investigate the trajectories of physical growth in 4 months corrected age among preterm infants discharged from the NICU and the impactors on these trajectories.

Methods

A prospective study was conducted among 318 preterm infants from September 2019 to April 2021 in Shanghai, China. Latent growth modeling was applied to identify the weight, length, and head circumference growth trajectories in 4 months corrected age and explore the effects of demographic and medical characteristics, infant stress during NICU stay, maternal postpartum depression, and mother-infant interaction on each trajectory.

Results

Unconditional latent growth models showed curve trajectories with increasingly slower growth in weight, length, and head circumference until 4 months of corrected age. Conditional latent growth models showed that a longer length of stay in the NICU and more skin punctures were negatively associated with weight at 40 weeks corrected gestational age (β = -0.43 and -0.19, respectively, P < 0.05). The maternal postpartum depression between 40 weeks corrected gestational age and 1 month corrected postnatal age was associated with a lower growth rate of length (β = -0.17, P = 0.040), while between 2 and 3 months corrected postnatal age, there were lower growth rates of weight and head circumference (β = -0.15 and -0.19, respectively, P < 0.05). The mother-infant interaction scores between 40 weeks corrected gestational age and 1 month corrected postnatal age negatively predicted the growth rate of weight (β = -0.19, P = 0.020).

Conclusion

The physical growth trajectories of preterm infants discharged from the NICU were influenced by infant stress during the NICU stay, maternal postpartum depression and mother-infant interaction.

Postnatal growth of small for gestational age late preterm infants: determinants of catch-up growth

BACKGROUND

Failure to recover growth is a risk reported in late preterm population. This study aimed to evaluate the auxological outcome of late preterm infants and identify factors associated with failure to recover growth.

METHODS

We enrolled late preterm infants with birth weight ≤10th percentile, followed up at High-Risk Infant Follow-up Service. We collected data at birth and at follow-up visits. A logistic regression analysis was performed to assess variables independently associated with growth failure.

RESULTS

The population consisted of 175 preterms. The percentage of children showing no weight recovery was 34% at 36 months. At logistic regression analysis, infants who had not regained weight at 12 months had a higher risk of not regaining weight even at 36 months. The same risk factor was highlighted for length catch-up growth. Moreover, infants fed any human milk at discharge were protected from not achieving both weight and length catch-up growth at 36 months.

CONCLUSION

These results indicate that children born late preterm and small for gestational age could fail to recover weight and stature growth in the first 36 months. The protective effect of human milk on failure to thrive highlights the importance of promoting breastfeeding in this population.

IMPACT

A significant number of SGA late preterms show a failure to recover weight and statural growth. Having experienced intrauterine growth restriction is associated with a greater chance of achieving statural catch-up growth. Being born singleton represents a risk factor for slower weight and height growth velocity. Breastmilk has a protective effect on failure to recover adequate weight and length in preterm SGA infants. This finding highlights the importance of promoting breastfeeding in this population.

Growth Patterns of Children With Short Stature in Adulthood According to Auxological Status and Maturity at Birth

CONTEXT

Prematurity carries a risk for impaired postnatal growth and long-term growth restriction. Especially children born SGA seem vulnerable for poor growth, as a persistent short stature can be observed in app 10-15% of these children.

OBJECTIVE

In this study we aimed to recognize differences in growth patterns of children according to sex, maturity, and auxological status at birth facilitating earlier identification of small-for-gestational-age (SGA) children with adult short stature.

METHODS

The growth data of 44 791 infants born between January 1, 1980, and December 30, 2012, among 2 pediatric cohorts with follow-up through December 31, 2020, were analyzed. A total of 5698 children with birth data had measurements at near final height (nfh) and at least 2 further points.

RESULTS

Preterm children (gestational age < 37 weeks) had a significantly lower mean nfh SDS than term children (preterm, -0.61; term, -0.18) and a higher likelihood of nfh < third percentile (preterm, 20.5%; term, 12.2%). SGA born children also had a lower mean nfh SD score (SDS) than children born appropriate for gestational age (AGA) (SGA, -1.06; AGA, -0.15) and a higher likelihood of nfh < third percentile (SGA, 28.2%; AGA 10.1%). Of 1204 SGA children, 672 (56%) showed successful catch-up growth (CUG) to nfh greater than or equal to the 10th percentile (SGA-CU), and 532 children (44%) did not (SGA-S). The difference in their mean nfh SDS (SGA-CU, -0.12; SGA-S -2.26) can only partly be explained by the differences in mean mid-parental height SDS (SGA-CU, -0.3; SGA-S, -1.19). During the first year, SGA-CU showed higher CUG (SGA-CU, +1.2 SDS; SGA-S, +0.45 SDS), which helps to discriminate between groups earlier.

CONCLUSION

Final growth outcome was influenced by prematurity and auxological status at birth, but not by sex. Height/length SDS increments during year 1 are instrumental to discern SGA children with later normal or short stature. While observing CUG until year 2 and 3 can add specificity, discrimination thereafter becomes difficult.