Growth trajectories of preterm infants: birth to 12 years

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.

Prevalence and predictive factors associated with stunting in preschool children in a governorate of Iraq: a community-based cross-sectional study

Introduction

The prevalence and risk factors of stunting in various geographical regions have been well investigated. However, not enough data exists regarding the communities in Iraq. This study investigated the prevalence and risk factors of stunting in preschool children in Halabja governorate.

Methods

The required data for the study was collected through a structured questionnaire form from the children's parents. Then, the height and weight of the children were measured. According to the World Health Organization Child Growth Standards and using the WHO Anthro Survey Analyser software, children were classified as "stunted" when their height-for-age z-score was below two standard deviations.

Results

A total of 646 children were included, of which 310 (48%) were male and 336 (52%) were female. The gestational age of 556 (86%) children was 9 months, while 84 (13%) were born between 7-9 months, and 6 (1%) were born in 7 months. Regarding feeding during the first 2 years of life, 229 children (35.4%) were exclusively breastfed, 93 (14.4%) were bottle-fed, and 324 (50.2%) had mixed feeding. The prevalence of stunting was 7.9% in the sample pool, with 4.6% of females and 3.3% of males. Among stunted children, 6.35% were term babies, and 1.55% were preterm babies. None of the studied factors had a significant association with stunting.

Conclusion

The prevalence of stunting in the studied population was 7.9%. However, we could not find any significant association between the studied factors and stunting. Thus, the factors that may significantly affect stunting in our area of study, especially the historical chemical warfare side effects, need to be more extensively investigated in future studies.

Comprehensive assessment of the genetic characteristics of small for gestational age newborns in NICU: from diagnosis of genetic disorders to prediction of prognosis

BACKGROUND

In China, ~1,072,100 small for gestational age (SGA) births occur annually. These SGA newborns are a high-risk population of developmental delay. Our study aimed to evaluate the genetic profile of SGA newborns in the newborn intensive care unit (NICU) and establish a prognosis prediction model by combining clinical and genetic factors.

METHODS

A cohort of 723 SGA and 1317 appropriate for gestational age (AGA) newborns were recruited between June 2018 and June 2020. Clinical exome sequencing was performed for each newborn. The gene-based rare-variant collapsing analyses and the gene burden test were applied to identify the risk genes for SGA and SGA with poor prognosis. The Gradient Boosting Machine framework was used to generate two models to predict the prognosis of SGA. The performance of two models were validated with an independent cohort of 115 SGA newborns without genetic diagnosis from July 2020 to April 2022. All newborns in this study were recruited through the China Neonatal Genomes Project (CNGP) and were hospitalized in NICU, Children's Hospital of Fudan University, Shanghai, China.

RESULTS

Among the 723 SGA newborns, 88(12.2%) received genetic diagnosis, including 42(47.7%) with monogenic diseases and 46(52.3%) with chromosomal abnormalities. SGA with genetic diagnosis showed higher rates in severe SGA(54.5% vs. 41.9%, P=0.0025) than SGA without genetic diagnosis. SGA with chromosomal abnormalities showed higher incidences of physical and neurodevelopmental delay compared to those with monogenic diseases (45.7% vs. 19.0%, P=0.012). We filtered out 3 genes (ITGB4, TXNRD2, RRM2B) as potential causative genes for SGA and 1 gene (ADIPOQ) as potential causative gene for SGA with poor prognosis. The model integrating clinical and genetic factors demonstrated a higher area under the receiver operating characteristic curve (AUC) over the model based solely on clinical factors in both the SGA-model generation dataset (AUC=0.9[95% confidence interval 0.84-0.96] vs. AUC=0.74 [0.64-0.84]; P=0.00196) and the independent SGA-validation dataset (AUC=0.76 [0.6-0.93] vs. AUC=0.53[0.29-0.76]; P=0.0117).

CONCLUSION

SGA newborns in NICU presented with roughly equal proportions of monogenic and chromosomal abnormalities. Chromosomal disorders were associated with poorer prognosis. The rare-variant collapsing analyses studies have the ability to identify potential causative factors associated with growth and development. The SGA prognosis prediction model integrating genetic and clinical factors outperformed that relying solely on clinical factors. The application of genetic sequencing in hospitalized SGA newborns may improve early genetic diagnosis and prognosis prediction.

Late preterm birth and growth trajectories during childhood: a linked retrospective cohort study

BACKGROUND

Evidence suggests that accelerated postnatal growth in children is detrimental for adult cardiovascular health. It is unclear whether children born late preterm (34-36 weeks) compared to full term (≥ 39 weeks), have different growth trajectories. Our objective was to evaluate the association between gestational age groups and growth trajectories of children born between 2006-2014 and followed to 2021 in Ontario, Canada.

METHODS

We conducted a retrospective cohort study of children from singleton births in TARGet Kids! primary care network with repeated measures of weight and height/length from birth to 14 years, who were linked to health administrative databases. Piecewise linear mixed models were used to model weight (kg/month) and height (cm/month) trajectories with knots at 3, 12, and 84 months. Analyses were conducted based on chronological age.

RESULTS

There were 4423 children included with a mean of 11 weight and height measures per child. The mean age at the last visit was 5.9 years (Standard Deviation: 3.1). Generally, the more preterm, the lower the mean value of weight and height until early adolescence. Differences in mean weight and height for very/moderate preterm and late preterm compared to full term were evident until 12 months of age. Weight trajectories were similar between children born late preterm and full term with small differences from 84-168 months (mean difference (MD) -0.04 kg/month, 95% CI -0.06, -0.03). Children born late preterm had faster height gain from 0-3 months (MD 0.70 cm/month, 95% CI 0.42, 0.97) and 3-12 months (MD 0.17 cm/month, 95% CI 0.11, 0.22).

CONCLUSIONS

Compared to full term, children born late preterm had lower average weight and height from birth to 14 years, had a slightly slower rate of weight gain after 84 months and a faster rate of height gain from 0-12 months. Follow-up is needed to determine if growth differences are associated with long-term disease risk.

Early-Life Weight Status and Risk of Childhood Asthma or Recurrent Wheeze in Preterm and Term Offspring

BACKGROUND

Excessive weight is associated with the development of childhood asthma. However, trends among preterm and term offspring may differ.

OBJECTIVE

To assess whether the association of longitudinal weight for age (WFA) and odds of asthma/recurrent wheeze in early life differs between children born preterm and those born at term.

METHODS

This study used prospectively collected data from the Vitamin D Antenatal Asthma Reduction Trial. Children (n = 804) were followed-up and anthropometric measurements, including WFA, were taken at birth and annually until the age of 6 years. The primary outcome was asthma/recurrent wheeze by age 3 and 6 years.

RESULTS

Among the offspring, 71 (8.8%) were premature. In all the children, the odds of asthma/recurrent wheeze increased by 15% (adjusted odds ratio [aOR], 1.15; 95% CI, 1.10-1.20; P < .001) by age 3 years and 9% (aOR, 1.09; 95% CI, 1.07-1.11; P < .001) by age 6 years for each unit increase in WFA z score. Odds were different between term and preterm offspring (Pinteraction < .001). In term offspring, the odds of having asthma/recurrent wheeze by age 3 and 6 years increased by 22% and 15%, respectively (aOR, 1.22, 95% CI, 1.16-1.27, P < .001, and aOR, 1.15, 95% CI, 1.11-1.18, P < .001). In preterm offspring, by age 3 years, odds of asthma/recurrent wheeze decreased by 10% for each unit increase in WFA z score (aOR, 0.90; 95% CI, 0.81-0.99; P = .030) and decreased by 27% by age 6 years (aOR, .73; 95% CI, 0.61-0.86; P < .001).

CONCLUSIONS

During early life, increasing standardized WFA is associated with higher odds of asthma/recurrent wheeze in term children. In contrast, in preterm children, a higher standardized WFA during catch-up growth may decrease the odds of asthma/recurrent wheeze associated with prematurity.

Molding influences of prematurity: Interviews with adults born preterm

BACKGROUND

Tremendous medical advancements over the last several decades have supported the survival of younger and sicker newborns. Substantial quantitative research exists about health and developmental outcomes following preterm birth, however, limited published literature has explored what this experience means to the survivors.

AIM

The purpose was to describe, interpret and understand how adults born preterm perceive prematurity to have affected their lives.

STUDY DESIGN

Qualitative thematic analysis.

METHODS

Semi-structured interviews were conducted with 33 adults born preterm from the RHODĒ Study, a longitudinal preterm birth cohort. A cross-section of participants with high and low early life medical and environmental risk was interviewed. Data were analyzed using a constructionist method of latent theme analysis.

RESULTS

From the data, 3 themes were identified: 1) My parents call me their miracle, 2) It's not a big deal, I'm the same as everyone else, 3) I've overcome a lot. Themes represent a continuum of experience, from positive to neutral to negative. Common life experiences of family, education, friends, and health are subthemes that help to illuminate how participants assign meaning to their prematurity. Meaning was linked to how typical or not participants perceive their health, learning and friends compared to peers.

CONCLUSION

Perceptions about prematurity and adversity are influenced by the ways parents and families represent prematurity in shared stories and actions. These findings should inform future research with adult survivors of prematurity. Participants identified ongoing need for support and advocacy, particularly from healthcare and education communities.

Growth patterns of preterm infants in Korea

With advancements in neonatal care and nutrition, the postnatal growth of preterm infants has improved; however, it remains an issue. Accurate assessments of growth using a standardized reference are needed to interpret the intrauterine and postnatal growth patterns of preterm infants. Growth in the earlier periods of life can contribute to later outcomes, and the refinement of postnatal growth failure is needed to optimize outcomes. Catchup growth occurs mainly before discharge and until 24 months of age, and very low birth weight infants in Korea achieve retarded growth later in life. Knowing an infant's perinatal history, reducing morbidity rates during admission, and performing regular monitoring after discharge are required. Preterm infants with a lower birth weight or who were small for gestational age are at increased risk of poor neurodevelopmental outcomes. Furthermore, poor postnatal growth is predictive of adverse neurodevelopmental outcomes. Careful monitoring and early intervention will contribute to better development outcomes and national public health improvements.

Effects of dibutyl phthalate on lipid metabolism in liver and hepatocytes based on PPARα/SREBP-1c/FAS/GPAT/AMPK signal pathway

Phateacid esters (PAEs), such as dibutyl phthalate (DBP), have been widely used and human exposure results into serious toxic effects; such as the development of fatty liver disease. In the present study, SD rat models for in vivo study (normal and fatty liver model group) and hepatocytes for in vitro study (normal and abnormal lipid metabolism model group) were established to determine the effects of DBP on liver function and discover the possible mechanisms. Meanwhile, the peroxisome proliferator activated receptor (PPARα) blocker, GW6471, with the Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) activator, AICAR, were applied in vitro study to clarify the role of PPARα/SREBP-1c/FAS/GPAT/AMPK signal pathway in the process. Results suggested that DBP could activate PPARα signaling pathway and affected the protein expression of SREBP, FAS and GPAT to cause hyperlipidemia and abnormal liver function. DBP also could inhibit the phosphorylation and activation of AMPK to inhibit the decomposition and metabolism of lipids. Interestingly, the effects of DBP could be alleviated by GW6471 and AICAR. Our experimental results provide reliable evidence that DBP exposure could further induce liver lipid metabolism disorder and other hepatic toxicity through PPARα/SREBP-1c/FAS/GPAT/AMPK signal pathway.

Body mass index trajectories and adiposity rebound during the first 6 years in Korean children: Based on the National Health Information Database, 2008-2015

PURPOSE

We analyzed the nationwide longitudinal data to explore body mass index (BMI) growth trajectories and the time of adiposity rebound (AR).

METHODS

Personal data of 84,005 subjects born between 2008 and 2012 were obtained from infant health check-ups which were performed at 5, 11, 21, 33, 45, 57, and 69 months. BMI trajectories of each subject were made according to sex and the timing of AR, which was defined as the lowest BMI occurred. Subjects were divided according to birth weight and AR timing as follows: very low birth weight (VLBW), 0.5 kg ≤ Bwt ≤ 1.5 kg; low birth weight (LBW), 1.5 kg < Bwt ≤ 2.5 kg; non-LBW, 2.5 kg < Bwt ≤ 5.0 kg; very early AR, before 45 months; early AR, at 57 months; and moderate-to-late AR, not until 69 months.

MAIN RESULTS

Median time point of minimum BMI was 45 months, and the prevalence rates of very early, early, and moderate-to-late AR were 63.0%, 16.6%, and 20.4%, respectively. BMI at the age of 57 months showed a strong correlation with AR timing after controlling for birth weight (P < 0.001). Sugar-sweetened beverage intake at 21 months (P = 0.02) and no-exercise habit at 57 months (P < 0.001) showed correlations with early AR. When VLBW and LBW subjects were analyzed, BMI at 57 months and breastfeeding at 11 months were correlated with rapid weight gain during the first 5 months (both P < 0.001).

CONCLUSIONS

Based on this first longitudinal study, the majority of children showed AR before 57 months and the degree of obesity at the age of 57 months had a close correlation with early AR or rapid weight gain during infancy.

The Maternal-Fetal Interface in Small-for-Gestational-Age Pregnancies Is Associated With a Reduced Quantity of Human Decidual NK Cells With Weaker Functional Ability

Small for gestational age (SGA) refers to a birth weight that is less than the 10th percentile of the mean weight of infants at the same gestational age. This condition is associated with a variety of complications, and a high risk of cardiovascular and cerebrovascular diseases in adulthood. Decidual natural killer (dNK) cells at the maternal–fetal interface have received significant research attention in terms of normal pregnancy or miscarriage; however, data relating to SGA are limited. In this study, we aimed to investigate the characteristics and regulatory role of dNK cells at the maternal–fetal interface in SGA. Using immunofluorescence assays, we found that dNK cells maintained close contact with extra-villous trophoblasts, and the proportion of dNK cells in SGA decreased more than in appropriate for gestational age (AGA). Flow cytometry also showed that there was a significantly lower percentage of dNK cells in SGA (25.01 ± 2.43%) than in AGA (34.25 ± 2.30%) (p = 0.0103). The expression of the inhibitory receptor NKG2A on dNK cells and the secretion levels of both perforin and TGF-β1 from dNK cells were significantly higher in SGA than in AGA, while the cytotoxicity of dNK cells in SGA against K562 cells was attenuated. Compared to AGA, the functional ability of dNK cells in SGA showed significant functional impairment in promoting proliferation, migration, invasion, and tube formation in trophoblast cells or vascular endothelial cells. The abnormal function of dNK cells may affect fetal growth and development, and could therefore participate in the pathogenesis of SGA.

Growth Assessment in Preterm Children from Birth to Preschool Age

Preterm infant growth is a major health indicator and needs to be monitored with an appropriate growth curve to achieve the best developmental and growth potential while avoiding excessive caloric intake that is linked to metabolic syndrome and hypertension later in life. New international standards for size at birth and postnatal growth for preterm infants are available and need implementation in clinical practice. A prospective, single center observational study was conducted to evaluate the in-hospital and long-term growth of 80 preterm infants with a mean gestational age of 33.3 ± 2.2 weeks, 57% males. Size at birth and at discharge were assessed using the INTERGROWTH-21^ST standards, at preschool age with World Health Organization (WHO) child growth standards. The employment of INTERGROWTH-21^ST Preterm Postnatal longitudinal standards during the in-hospital follow-up significantly reduced the diagnosis of short term extrauterine growth restriction when compared to commonly used cross sectional neonatal charts, with significant lower loss of percentiles between birth and term corrected age (p < 0.0001). The implementation of a package of standards at birth, preterm postnatal growth standards and WHO child growth standards proved to be consistent, with correlation between centile at birth and at follow-up, and therefore effective in monitoring growth in a moderate and late preterm infant cohort without chronic or major morbidities. Infants identified as small for gestational age at birth showed significantly more frequently a need for auxological referral.

[Catch-up growth and associated factors in very low birth weight infants]

INTRODUCTION

The characteristics of catch-up growth in very low birth weight infants (VLBW) have not been clearly established. The aim of this study was to analyse the height catch-up and some associated factors in a cohort of VLBW (birth weight<1,500g) from birth to age 14 years.

METHODS

We obtained retrospective data on weight and height at birth and ages one, 2, 3, 4, 6, 8, 10, 12 and 14 years in a cohort of 170 VLBW. We compared these anthropometric values with those documented in a control group.

RESULTS

Thirty-seven children (21.8%) were born with an extremely low birth weight and 32 (18.8%) extremely preterm. At 10 years of age, 7% of VLBW (1,000-1,500g) and 35% of extremely low birth weight (<1,500g) children had short stature (P=.001). Almost all VLBW children who had a normal height at ages 2, 4 and 10 years had exhibited adequate weight catch-up in previous evaluations. We found that extremely low birth weight and extremely preterm were independent predictors for inadequate height catch-up.

CONCLUSION

The growth pattern of VLBW children has specific characteristics. The catch-up in weight seems to be an important factor for catch-up in height, and therefore a thorough nutritional follow-up is recommended in these children.

Longitudinal growth changes from birth to 8-9 years in preterm and full term births

BACKGROUND

The aim of this study is to assess the effect of age at adiposity rebound (AR) and changes in growth between birth and 6 months on growth status at 8-9 years in children born term and preterm. Age at AR is inversely correlated with risk for later obesity in children born full term, but has not been analyzed in children born preterm.

METHODS

Birth anthropometrics, and weight and length/height data from age 6 months through 8-9 years were recorded for 175 children born in 2008 in the military health system. Calculated variables include body mass index (BMI, kg/m2), Z-scores, and age at AR.

RESULTS

Age at AR could be calculated for 150 children (32% preterm); average age was 5.4 years and 5.3 years for children born term and preterm, respectively (NS). For children born term and preterm, there was a significant correlation between younger age at AR and higher BMI Z-score at 8-9 years (r = - 0.685), and a direct relationship between weight Z-score change from birth to 6 months and weight Z-scores at 8-9 years (p = 0.034).

CONCLUSIONS

Younger age at AR correlates with higher BMI Z-score at 8-9 years in children born both term and preterm. Weight gain from birth to 6 months correlates with weight Z-score at 8-9 years. These results emphasize the importance of younger age at AR in addition to greater early weight gain as an indicator of later obesity.

Gastrointestinal sequelae and growth impairment at school age following necrotising enterocolitis in the newborn period

AIM

To evaluate gastrointestinal sequelae and growth impairment at school age in children who suffered from necrotising enterocolitis (NEC).

METHODS

This historic cohort study compared all surviving children born in Denmark between 1 January 2002 and 31 December 2011 with NEC in the newborn period, to surviving children without NEC, but same gestational age, birthweight and year of birth. Outcomes were investigated through a parental questionnaire, including gastrointestinal and growth-related outcomes. We performed exploratory ad hoc analysis, by adjusting for possible confounding and by dividing NEC children into surgical and medical.

RESULTS

In total, 163 children with NEC (50%) and 237 (36%) without NEC completed the parental questionnaire. Episodes of diarrhoea were more often reported in the NEC group (p = 0.0002). The increased risk seemed to be limited to those who underwent surgery for NEC. The absence from school (1.67 versus 1.31 days), rate of low height for age (17.9 versus 12.1%) and weight (29.9 versus 31.6 kg) did not differ significantly between children with NEC and children without NEC.

CONCLUSION

Our findings suggest that long-term gastrointestinal complications following NEC appeared to be of little clinical importance at the population level and therefore do not encourage specific routine follow-up.

Growth patterns during early childhood in children born small for gestational age and moderate preterm

Today we lack knowledge if size at birth and gestational age interact regarding postnatal growth pattern in children born at 32 gestational weeks or later. This population-based cohort study comprised 41,669 children born in gestational weeks 32–40 in Uppsala County, Sweden, between 2000 and 2015. We applied a generalized least squares model including anthropometric measurements at 1.5, 3, 4 and 5 years. We calculated estimated mean height, weight and BMI for children born in week 32 + 0, 35 + 0 or 40 + 0 with birthweight 50^th percentile (standardized appropriate for gestational age, sAGA) or 3^rd percentile (standardized small for gestational age, sSGA). Compared with children born sAGA at gestational week 40 + 0, those born sAGA week 32 + 0 or 35 + 0 had comparable estimated mean height, weight and BMI after 3 years of age. Making the same comparison, those born sSGA week 32 + 0 or 35 + 0 were shorter and lighter with lower estimated mean BMI throughout the whole follow-up period. Our findings suggest that being born SGA and moderate preterm is associated with short stature and low BMI during the first five years of life. The association seemed stronger the shorter gestational age at birth.

Development of growth equations from longitudinal studies of body weight and height in the full term and preterm neonate: From birth to four years postnatal age

Physiologically based pharmacokinetic (PBPK) models are developed from compound-independent information to describe important anatomical and physiological characteristics of an individual or population of interest. Modeling pediatric populations is challenging because of the rapid changes that occur during growth, particularly in the first few weeks and months after birth. Neonates who are born premature pose several unique challenges in PBPK model development. To provide appropriate descriptions for body weight (BW) and height (Ht) for age and appropriate incremental gains in PBPK models of the developing preterm and full term neonate, anthropometric measurements collected longitudinally from 1,063 preterm and 158 full term neonates were combined with 2,872 cross-sectional measurements obtained from the NHANES 2007-2010 survey. Age-specific polynomial growth equations for BW and Ht were created for male and female neonates with corresponding gestational birth ages of 25, 28, 31, 34, and 40 weeks. Model-predicted weights at birth were within 20% of published fetal/neonatal reference standards. In comparison to full term neonates, postnatal gains in BW and Ht were slower in preterm subgroups, particularly in those born at earlier gestational ages. Catch up growth for BW in neonates born at 25, 28, 31, and 34 weeks gestational age was complete by 13, 8, 6, and 2 months of life (males) and by 10, 6, 5, and 2 months of life (females), respectively. The polynomial growth equations reported in this paper represent extrauterine growth in full term and preterm neonates and differ from the intrauterine growth standards that were developed for the healthy unborn fetus.

Tobacco Exposure and Conditional Weight-for-Length Gain by 2 Years of Age

Objective

To prospectively examine dose-response and timing effects of prenatal (PTE) and postnatal tobacco exposure on obesity risk assessed by conditional weight-for-length gain (CWFLG), by 2 years of age. CWFLG over the first 2 years of life was examined for 117 PTE and 57 nonexposed children. Repeated assessments of PTE were conducted beginning in the first trimester of pregnancy, using multiple methods. PTE or postnatal exposure status was not predictive of CWFLG. However, there was a dose-response association and an association with fetal exposure ascertained by infant meconium positive for nicotine and metabolites. PTE is related to restricted growth at birth, yet associated with accelerated CWFLG by 2 years of age, a measure that controls for birthweight differences. Results highlight the importance of examining dose-response and timing of exposure associations, along with the importance of obesity risk-reduction interventions within the first 2 years of life among PTE children.

MANAGEMENT OF ENDOCRINE DISEASE: Growth and growth hormone therapy in short children born preterm

Approximately 15 million babies are born preterm across the world every year, with less than 37 completed weeks of gestation. Survival rates increased during the last decades with the improvement of neonatal care. With premature birth, babies are deprived of the intense intrauterine growth phase, and postnatal growth failure might occur. Some children born prematurely will remain short at later ages and adult life. The risk of short stature increases if the child is also born small for gestational age. In this review, the effects of being born preterm on childhood growth and adult height and the hormonal abnormalities possibly associated with growth restriction are discussed, followed by a review of current information on growth hormone treatment for those who remain with short stature during infancy and childhood.

The association of maternal vitamin D status with infant birth outcomes, postnatal growth and adiposity in the first 2 years of life in a multi-ethnic Asian population: the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort study

Maternal vitamin D status during pregnancy has been associated with infant birth and postnatal growth outcomes, but reported findings have been inconsistent, especially in relation to postnatal growth and adiposity outcomes. In a mother-offspring cohort in Singapore, maternal plasma vitamin D was measured between 26 and 28 weeks of gestation, and anthropometric measurements were obtained from singleton offspring during the first 2 years of life with 3-month follow-up intervals to examine birth, growth and adiposity outcomes. Associations were analysed using multivariable linear regression. Of a total of 910 mothers, 13·2 % were vitamin D deficient (<50 nmol/l) and 26·5 % were insufficient (50-75 nmol/l). After adjustment for potential confounders and multiple testing, no statistically significant associations were observed between maternal vitamin D status and any of the birth outcomes - small for gestational age (OR 1·00; 95 % CI 0·56, 1·79) and pre-term birth (OR 1·16; 95 % CI 0·64, 2·11) - growth outcomes - weight-for-age z-scores, length-for-age z-scores, circumferences of the head, abdomen and mid-arm at birth or postnatally - and adiposity outcomes - BMI, and skinfold thickness (triceps, biceps and subscapular) at birth or postnatally. Maternal vitamin D status in pregnancy did not influence infant birth outcomes, postnatal growth and adiposity outcomes in this cohort, perhaps due to the low prevalence (1·6 % of the cohort) of severe maternal vitamin D deficiency (defined as of <30·0 nmol/l) in our population.

Three-year growth response to growth hormone treatment in very young children born small for gestational age-data from KIGS

CONTEXT

Children born small for gestational age (SGA) with poor growth during the first years of life may remain short in stature during childhood and as adults.

OBJECTIVE

To evaluate the 3-year growth response to GH treatment in very young short children born SGA, and to test the existing predictions models for growth response developed for older SGA children.

SETTING

KIGS (The Pfizer International Growth Database).

PATIENTS

A total of 620 SGA children (birth length and/or weight below -2 SD score [SDS]) on GH treatment, 156 in the 2- to 4-year-old group (100 boys; median age, 3.3 y), and 464 in the 4- to 6-year-old group (284 boys; median age, 4.9 y).

RESULTS

Median values and 10th-90th percentiles are presented. Both groups presented a significant increase in height velocity during GH treatment. Median height SDS increased from -3.9 (-5.4 to -2.9) at the start to -2.2 (-3.8 to -1.0) at 3 years in the 2- to 4-year-old group (P < .01) and from -3.4 (-4.5 to -2.6) to -2.0 (-3.3 to -0.9) in the 4- to 6-year-old group (P < .01). Median weight SDS increased from -3.8 (-5.9 to -2.4) to -2.1 (-4.1 to -0.5) in the 2- to 4-year-old group (P < .01). Respective values for the 4- to 6-year-old group were -3.1 (-4.8 to -1.8) to -1.6 (-3.1 to -0.1) SDS (P < .01). First- and second-year growth response could be estimated by the SGA model.

CONCLUSION

Very young children born SGA without spontaneous catch-up growth presented a significant improvement in height and weight during the 3 years of GH treatment. Growth response could be estimated by the SGA model.

[Growth of preterm-born children]

Children born prematurely might experience a period of growth restriction just after birth. Catch-up growth begins during the first months of life and can be slow and progressive. These children may remain shorter and thinner throughout infancy and childhood compared to children born at term. In some cases, complete catch-up growth occurs only during adolescence. However, some children do not completely recover growth, and adults born prematurely are at increased risk of short stature. Impaired growth is more frequent in those born preterm and small for gestational age. Factors such as target height, birth weight, gestational age, neonatal morbidities and maternal education interfere in growth potential. Special attention should be given to children born preterm during the whole growth period.

17-year outcome of preterm infants with diverse neonatal morbidities: Part 1--Impact on physical, neurological, and psychological health status

PURPOSE

The purpose of this study was to comprehensively examine physical, neurological, and psychological health in a U.S. sample of 180 infants at age 17.

DESIGN AND METHODS

The World Health Organization International Classification of Functioning, Disability and Health model framed the health-related domains and contextual factors. Assessments included growth, chronic conditions, neurological status, and psychological health.

RESULTS

Physical health, growth, and neurological outcomes were poorer in the preterm groups. Minor neurological impairment was related to integrative function. Preterm survivors reported higher rates of depression, anxiety, and inattention/hyperactivity.

PRACTICE IMPLICATIONS

Complex health challenges confront preterm survivors at late adolescence, suggesting the necessity of continued health surveillance.

Characteristic Processes in Close Peer Friendships of Preterm Infants at Age 12

Close friendships become important at middle-school age and are unexplored in adolescents born prematurely. The study aimed to characterize friendship behaviors of formerly preterm infants at age 12 and explore similarities and differences between preterm and full-term peers on dyadic friendship types. From the full sample of N=186, one hundred sixty-six 12-year-old adolescents (40 born full term, 126 born preterm) invited a close friend to a 1.5 hour videotaped laboratory play session. Twenty adolescents were unable to participate due to scheduling conflicts or developmental disability. Characteristic friendship behaviors were identified by Q-sort followed by Q-factoring analysis. Friendship duration, age, and contact differed between the full-term and preterm groups but friendship activities, behaviors, and quality were similar despite school service use. Three Q-factors, leadership, distancing, and mutual playfulness, were most characteristic of all dyads, regardless of prematurity. These prospective, longitudinal findings demonstrate diminished prematurity effects at adolescence in peer friendship behavior and reveal interpersonal dyadic processes that are important to peer group affiliation and other areas of competence.

Growth hormone treatment in short children born prematurely--data from KIGS

CONTEXT

Children born prematurely with growth failure might benefit from GH treatment.

OBJECTIVES

The aim was to evaluate the first year growth response to GH treatment in short children born prematurely and to identify predictors of the growth response.

DESIGN/PATIENTS

A total of 3215 prepubertal children born prematurely who were on GH treatment were selected from KIGS (The Pfizer International Growth Database), a large observational database. They were classified according to gestational age as preterm (PT; 33 to no more than 37 wk) and very preterm (VPT; <33 wk), and according to birth weight as appropriate for gestational age [AGA; between -2 and +2 sd score (SDS)] and small for gestational age (SGA; -2 SDS or below).

RESULTS

Four groups were identified: PT AGA (n = 1928), VPT AGA (n = 629), PT SGA (n = 519), and VPT SGA (n = 139). GH treatment was started at a median age of 7.5, 7.2, 6.7, and 6.0 yr, respectively. After the first year of GH treatment, all four groups presented a significant increase in weight gain and height velocity, with a median increase in height SDS higher than 0.6. Using multiple stepwise regression analysis, 27% of the variation in height velocity could be explained by the GH dose, GH peak during provocative test, weight and age at GH start, adjusted parental height, and birth weight SDS. The first year growth response of the children born PT and SGA could be estimated by the SGA model published previously.

CONCLUSION

Short children born prematurely respond well to the first year of GH treatment. Long-term follow-up is needed.

Serum dioxins and polychlorinated biphenyls are associated with growth among Russian boys

OBJECTIVE

We evaluated the associations of serum dioxins and polychlorinated biphenyls (PCBs) with longitudinally assessed growth measurements among peripubertal Russian boys.

METHODS

A total of 499 boys from Chapaevsk, Russia, aged 8 to 9 years were enrolled in the study from 2003 to 2005 and were followed prospectively for 3 years. Blood samples were collected and physical examinations were conducted at entry and repeated at annual study visits. Multivariate mixed-effects regression models for repeated measures were used to examine the associations of serum dioxins and PCBs with longitudinal measurements of BMI, height, and height velocity.

RESULTS

Serum dioxin (total 2005 toxic equivalency [TEQ] median: 21.1 pg/g lipid) and PCBs (median sum of PCBs: 250 ng/g lipid) were measured in 468 boys. At study entry and during 3 years of follow-up, >50% of the boys had age-adjusted BMI and height z scores within 1 SD of World Health Organization-standardized mean values for age. Boys in the highest exposure quintile of the sum of dioxin and PCB concentrations and total TEQs had a significant decrease in mean BMI z scores of 0.67 for dioxins and TEQs and 1.04 for PCBs, compared with boys in the lowest exposure quintile. Comparison of the highest versus the lowest quintile revealed that higher serum PCB concentrations were associated with significantly lower height z scores (mean z-score decrease: 0.41) and height velocity (mean decrease: 0.19 cm/year) after 3 years of follow-up.

CONCLUSIONS

Our findings suggest that exposures to dioxins and PCBs are associated with reduced growth during the peripubertal period and may compromise adult body mass, stature, and health.

Calculating postnatal growth velocity in very low birth weight (VLBW) premature infants

OBJECTIVE

Currently, there is no standardized approach to the calculation of growth velocity (GV; g kg (-1) day(-1)) in hospitalized very low birth weight (VLBW) infants. Thus, differing methods are used to estimate GV, resulting in different medical centers and studies reporting growth results that are difficult to compare. The objective of this study was to compare actual GV calculated from infant daily weights during hospitalization in a Neonatal Intensive Care Unit (NICU) with estimated GV using two mathematical models that have been shown earlier to provide good estimated GVs in extremely low birth weight (ELBW) infants: an exponential model (EM) and a 2-Point model (2-PM).

STUDY DESIGN

Daily weights from 81 infants with birth weights (BWs) of 1000 to 1499 g were used to calculate actual GV in daily increments from two starting points: (1) birth and (2) day of life (DOL) of regaining BW. These daily GV values were then averaged over the NICU stay to yield overall NICU GV from the two starting points. We compared these actual GV with estimated GV calculated using the EM and 2-PM methods.

RESULTS

The mean absolute difference between actual and EM estimates of GV showed <1% error for 100% of infants from both starting points. The mean absolute difference between actual and 2-PM estimates showed <1% error for only 38 and 44% of infants from birth and regaining BW, respectively. The EM was unaffected by decreasing BW and increasing length of NICU stay, whereas the accuracy of the 2-PM was diminished significantly (P<0.001) by both factors.

CONCLUSION

In contrast to the 2-PM, the EM provides an extremely accurate estimate of GV in larger VLBW infants, and its accuracy is unaffected by common infant factors. The EM has now been validated for use in all VLBW infants to assess growth and provides a simple-to-use and consistent approach.

Triplets across the first 5 years: the discordant infant at birth remains at developmental risk

OBJECTIVES

To examine whether the risk posed to infant development by triplet birth persists into childhood and whether growth-discordant triplets are at a particularly high developmental risk.

METHODS

Twenty-one sets of triplets were matched with 21 sets of twins and 21 singletons (N = 126) for medical and demographic conditions and were followed from birth to 5 years. At 6, 12, and 24 months, cognitive development was assessed and mother-infant interactions were coded for maternal sensitivity and child social engagement. At 5 years, the children's cognitive development and neuropsychological skills were tested, social engagement was coded from mother-child interactions, and behavior problems were examined. Maternal adjustment was assessed during interviews at 1 and 5 years.

RESULTS

Although triplets showed lower cognitive performance at 6, 12, and 24 months as compared with singletons and twins, differences were attenuated by 5 years in both global IQ and executive functions. Similarly, the lower social engagement observed across infancy and the higher internalizing symptoms reported at 2 years for those in the triplet group were no longer found at 5 years. Difficulties in maternal adjustment among mothers of triplets decreased from 1 to 5 years. However, in 65.2% of the initial sample there was a weight discordance of >15% at birth, and the discordant triplets showed poorer cognitive and social development as compared with their siblings across infancy. At 5 years, the discordant children demonstrated lower cognitive and executive functions performance, decreased social engagement, and higher internalizing symptoms as compared with both siblings and peers.

CONCLUSIONS

Whereas most triplets catch up after an early developmental delay, the risk for discordant triplets seems to persist into childhood. Such infants, who are at both biological and environmental risk, should receive special and consistent professional care.