Growth of extremely preterm survivors from birth to 18 years of age compared with term controls

Romantic and sexual relationships of young adults born very preterm: An individual participant data meta-analysis

AIM

To compare romantic and sexual relationships between adults born very preterm (VP; <32 weeks of gestation) or with very low birth weight (VLBW; <1500 g) and at term, and to evaluate potential biological and environmental explanatory factors among VP/VLBW participants.

METHODS

This individual participant data (IPD) meta-analysis included longitudinal studies assessing romantic and sexual relationships in adults (mean sample age ≥ 18 years) born VP/VLBW compared with term-born controls. Following PRISMA-IPD guidelines, 11 of the 13 identified cohorts provided IPD from 1606 VP/VLBW adults and 1659 term-born controls. IPD meta-analyses were performed using one-stage approach.

RESULTS

Individuals born VP/VLBW were less likely to be in a romantic relationship (OR 0.49; 95% CI 0.31-0.76), to be married/cohabiting (OR 0.70, 95% CI 0.53-0.92), or to have had sexual intercourse (OR 0.21, 95% CI 0.09-0.36) than term-born adults. If sexually active, VP/VLBW participants were more likely to experience their first sexual intercourse after the age of 18 years (OR 1.93, 95% CI 1.24-3.01) than term-born adults. Among VP/VLBW adults, males, and those with neurosensory impairment were least likely to experience romantic relationships.

CONCLUSIONS

These findings reflect less optimal social functioning and may have implications for socioeconomic and health outcomes of adults born VP/VLBW.

Correction: Accelerated weight gain, prematurity, and the risk of childhood obesity: A meta-analysis and systematic review

[This corrects the article DOI: 10.1371/journal.pone.0232238.].

Postnatal growth in small vulnerable newborns: a longitudinal study of 2 million Brazilians using routine register-based linked data

BACKGROUND

Preterm, low-birth weight (LBW) and small-for-gestational age (SGA) newborns have a higher frequency of adverse health outcomes, including linear and ponderal growth impairment.

OBJECTIVE

To describe the growth trajectories and to estimate catch-up growth during the first 5 y of life of small newborns according to 3 vulnerability phenotypes (preterm, LBW, SGA).

METHODS

Longitudinal study using linked data from the 100 Million Brazilian Cohort baseline, the Brazilian National Live Birth System (SINASC), and the Food and Nutrition Surveillance System (SISVAN) from 2011 to 2017. We estimated the length/height-for-age (L/HAZ) and weight-for-age z-score (WAZ) trajectories from children of 6-59 mo using the linear mixed model for each vulnerable newborn phenotype. Growth velocity for both L/HAZ and WAZ was calculated considering the change (Δ) in the mean z-score between 2 time points. Catch-up growth was defined as a change in z-score > 0.67 at any time during follow-up.

RESULTS

We analyzed 2,021,998 live born children and 8,726,599 observations. The prevalence of at least one of the vulnerable phenotypes was 16.7% and 0.6% were simultaneously preterm, LBW, and SGA. For those born at term, all phenotypes had a period of growth recovery from 12 mo. For preterm infants, the onset of L/HAZ growth recovery started later at 24 mo and the growth trajectories appear to be lower than those born at term, a condition aggravated among children with the 3 phenotypes. Preterm and female infants seem to experience slower growth recovery than those born at term and males. The catch-up growth occurs at 24-59 mo for males preterm: preterm + AGA + NBW (Δ = 0.80), preterm + AGA + LBW (Δ = 0.88), and preterm + SGA + LBW (Δ = 1.08); and among females: term + SGA + NBW (Δ = 0.69), term + AGA + LBW (Δ = 0.72), term + SGA + LBW (Δ = 0.77), preterm + AGA + LBW (Δ = 0.68), and preterm + SGA + LBW (Δ = 0.83).

CONCLUSIONS

Children born preterm seem to reach L/HAZ and WAZ growth trajectories lower than those attained by children born at term, a condition aggravated among the most vulnerable.

Effect of preterm birth on growth and blood pressure in adulthood in the Pelotas 1993 cohort

BACKGROUND

Preterm birth has been associated with increased risk of hypertension and cardiovascular disease later in adulthood, attributed to cardiovascular and metabolic alterations in early life. However, there is paucity of evidence from low- and middle-income countries (LMICs).

METHODS

We investigated the differences between preterm (<37 weeks gestational age) and term-born individuals in birth length and weight as well as adult (18 and 20 years) height, weight and blood pressure in the Brazilian 1993 Pelotas birth cohort using linear regressions. Analyses were adjusted for the maternal weight at the beginning of pregnancy and maternal education and family income at childbirth. Additional models were adjusted for body mass index (BMI) and birthweight. Separate analyses were run for males and females. The complete sample was analysed with an interaction term for sex.

RESULTS

Of the 3585 babies included at birth, 3010 were followed up in adulthood at 22 years. Preterm participants had lower length and weight at birth. This difference remained for male participants in adulthood, but female participants were no shorter than their term counterparts by 18 years of age. At 22 years, females born preterm had lower blood pressures (systolic blood pressure -1.00 mmHg, 95%CI -2.7, 0.7 mmHg; diastolic blood pressure -1.1 mmHg, 95%CI -2.4, 0.3 mmHg) than females born at term. These differences were not found in male participants.

CONCLUSIONS

In this Brazilian cohort we found contrasting results regarding the association of preterm birth with blood pressure in young adulthood, which may be unique to an LMIC.

Prematurity and Low Birth Weight and Their Impact on Childhood Growth Patterns and the Risk of Long-Term Cardiovascular Sequelae

Preterm birth (before 37 completed weeks of gestation) is a global health problem, remaining the main reason for neonatal mortality and morbidity. Improvements in perinatal and neonatal care in recent decades have been associated with a higher survival rate of extremely preterm infants, leading to a higher risk of long-term sequelae in this population throughout life. Numerous surveillance programs for formerly premature infants continue to focus on neurodevelopmental disorders, while long-term assessment of the impact of preterm birth and low birth weight on child growth and the associated risk of cardiovascular disease in young adults is equally necessary. This review will discuss the influence of prematurity and low birth weight on childhood growth and cardiovascular risk in children, adolescents and young adults. The risk of cardiovascular and metabolic disorders is increased in adult preterm survivors. In early childhood, preterm infants may show elevated blood pressure, weakened vascular growth, augmented peripheral vascular resistance and cardiomyocyte remodeling. Increased weight gain during the early postnatal period may influence later body composition, promote obesity and impair cardiovascular results. These adverse metabolic alterations contribute to an increased risk of cardiovascular incidents, adult hypertension and diabetes. Preterm-born children and those with fetal growth restriction (FGR) who demonstrate rapid changes in their weight percentile should remain under surveillance with blood pressure monitoring. A better understanding of lifelong health outcomes of preterm-born individuals is crucial for developing strategies to prevent cardiovascular sequelae and may be the basis for future research to provide effective interventions.

DNA methylation age at birth and childhood: performance of epigenetic clocks and characteristics associated with epigenetic age acceleration in the Project Viva cohort

BACKGROUND

Epigenetic age acceleration (EAA) and epigenetic gestational age acceleration (EGAA) are biomarkers of physiological development and may be affected by the perinatal environment. The aim of this study was to evaluate performance of epigenetic clocks and to identify biological and sociodemographic correlates of EGAA and EAA at birth and in childhood. In the Project Viva pre-birth cohort, DNA methylation was measured in nucleated cells in cord blood (leukocytes and nucleated red blood cells, N = 485) and leukocytes in early (N = 120, median age = 3.2 years) and mid-childhood (N = 460, median age = 7.7 years). We calculated epigenetic gestational age (EGA; Bohlin and Knight clocks) and epigenetic age (EA; Horvath and skin & blood clocks), and respective measures of EGAA and EAA. We evaluated the performance of clocks relative to chronological age using correlations and median absolute error. We tested for associations of maternal-child characteristics with EGAA and EAA using mutually adjusted linear models controlling for estimated cell type proportions. We also tested associations of Horvath EA at birth with childhood EAA.

RESULTS

Bohlin EGA was strongly correlated with chronological gestational age (Bohlin EGA r = 0.82, p < 0.001). Horvath and skin & blood EA were weakly correlated with gestational age, but moderately correlated with chronological age in childhood (r = 0.45-0.65). Maternal smoking during pregnancy was associated with higher skin & blood EAA at birth [B (95% CI) = 1.17 weeks (- 0.09, 2.42)] and in early childhood [0.34 years (0.03, 0.64)]. Female newborns and children had lower Bohlin EGAA [- 0.17 weeks (- 0.30, - 0.04)] and Horvath EAA at birth [B (95% CI) = - 2.88 weeks (- 4.41, - 1.35)] and in childhood [early childhood: - 0.3 years (- 0.60, 0.01); mid-childhood: - 0.48 years (- 0.77, - 0.18)] than males. When comparing self-reported Asian, Black, Hispanic, and more than one race or other racial/ethnic groups to White, we identified significant differences in EGAA and EAA at birth and in mid-childhood, but associations varied across clocks. Horvath EA at birth was positively associated with childhood Horvath and skin & blood EAA.

CONCLUSIONS

Maternal smoking during pregnancy and child sex were associated with EGAA and EAA at multiple timepoints. Further research may provide insight into the relationship between perinatal factors, pediatric epigenetic aging, and health and development across the lifespan.

Comparing autism phenotypes in children born extremely preterm and born at term

Children born preterm are at increased risk for autism spectrum disorder (ASD). There is limited knowledge about whether ASD phenotypes in children born preterm differ from children born at term. The objective of this study was to compare ASD core symptoms and associated characteristics among extremely preterm (EP) and term-born children with ASD. EP participants (n = 59) from the Extremely Low Gestational Age Newborn Study who met diagnostic criteria for ASD at approximately 10 years of age were matched with term-born participants from the Simons Simplex Collection on age, sex, spoken language level, and nonverbal IQ. Core ASD symptomatology was evaluated with the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS). Developmental milestones, anthropometrics, seizure disorder, and psychiatric symptoms were also investigated. The EP group had lower parent-reported symptom scores on ADI-R verbal communication, specifically stereotyped language, and restricted, repetitive behaviors. There were no between-group differences on ADI-R nonverbal communication and ADI-R reciprocal social interaction or with direct observation on the ADOS-2. The EP group was more likely to have delayed speech milestones and lower physical growth parameters. Results from female-only analyses were similar to those from whole-group analyses. In sum, behavioral presentation was similar between EP and IQ- and sex-matched term-born children assessed at age 10 years, with the exception of less severe retrospectively reported stereotyped behaviors, lower physical growth parameters, and increased delays in language milestones among EP-born children with ASD.

Gestational age and trajectories of body mass index and height from birth through adolescence in the Danish National Birth Cohort

Preterm birth is associated with smaller body dimensions at birth. The impact on body size in later life, measured by body mass index (BMI) and height, remains unclear. A prospective register-based cohort study with 62,625 singletons from the Danish National Birth Cohort born 1996-2003 for whom information on gestational age (GA) at birth, length or weight at birth, and at least two growth measurements scheduled at the ages of 5 and 12 months, and 7, 11 and 18 years were available. Linear mixed effects with splines, stratified by sex, and adjusted for confounders were used to estimate standardised BMI and height. GA was positively associated with BMI in infancy, but differences between preterm and term children declined with age. By age 7, preterm children had slightly lower BMI than term children, whereas no difference was observed by adolescence (mean difference in BMI z-score - 0.28 to 0.15). GA was strongly associated with height in infancy, but mean differences between individuals born preterm and term declined during childhood. By adolescence, the most preterm individuals remained shorter than their term peers (mean difference in height z-score from - 1.00 to - 0.28). The lower BMI in preterm infants relative to term infants equalizes during childhood, such that by adolescence there is no clear difference. Height is strongly positively associated with GA in early childhood, whilst by end of adolescence individuals born preterm remain slightly shorter than term peers.

A. Sørensen T, Elhakeem A, Santos AC, Pinot de Moira A, Heude B, Iñiguez C, Pizzi C, Simons E, Voerman E, Corpeleijn E, Zariouh F, Santorelli G, Inskip HM, Barros H, Carson J, Harris JR, Nader JL, Ronkainen J, Strandberg-Larsen K, Santa-Marina L, Calas L, Cederkvist L, Popovic M, Charles MA, Welten M, Vrijheid M, Azad M, Subbarao P, Burton P, Mandhane PJ, Huang RC, Wilson RC, Haakma S, Fernández-Barrés S, Turvey S, Santos S, Tough SC, Sebert S, Moraes TJ, Salika T, Jaddoe VWV, Lawlor DA, Nybo Andersen AM. Gestational age at birth and body size from infancy through adolescence: An individual participant data meta-analysis on 253,810 singletons in 16 birth cohort studies

BACKGROUND

Preterm birth is the leading cause of perinatal morbidity and mortality and is associated with adverse developmental and long-term health outcomes, including several cardiometabolic risk factors and outcomes. However, evidence about the association of preterm birth with later body size derives mainly from studies using birth weight as a proxy of prematurity rather than an actual length of gestation. We investigated the association of gestational age (GA) at birth with body size from infancy through adolescence.

METHODS AND FINDINGS

We conducted a two-stage individual participant data (IPD) meta-analysis using data from 253,810 mother-child dyads from 16 general population-based cohort studies in Europe (Denmark, Finland, France, Italy, Norway, Portugal, Spain, the Netherlands, United Kingdom), North America (Canada), and Australasia (Australia) to estimate the association of GA with body mass index (BMI) and overweight (including obesity) adjusted for the following maternal characteristics as potential confounders: education, height, prepregnancy BMI, ethnic background, parity, smoking during pregnancy, age at child's birth, gestational diabetes and hypertension, and preeclampsia. Pregnancy and birth cohort studies from the LifeCycle and the EUCAN-Connect projects were invited and were eligible for inclusion if they had information on GA and minimum one measurement of BMI between infancy and adolescence. Using a federated analytical tool (DataSHIELD), we fitted linear and logistic regression models in each cohort separately with a complete-case approach and combined the regression estimates and standard errors through random-effects study-level meta-analysis providing an overall effect estimate at early infancy (>0.0 to 0.5 years), late infancy (>0.5 to 2.0 years), early childhood (>2.0 to 5.0 years), mid-childhood (>5.0 to 9.0 years), late childhood (>9.0 to 14.0 years), and adolescence (>14.0 to 19.0 years). GA was positively associated with BMI in the first decade of life, with the greatest increase in mean BMI z-score during early infancy (0.02, 95% confidence interval (CI): 0.00; 0.05, p < 0.05) per week of increase in GA, while in adolescence, preterm individuals reached similar levels of BMI (0.00, 95% CI: -0.01; 0.01, p 0.9) as term counterparts. The association between GA and overweight revealed a similar pattern of association with an increase in odds ratio (OR) of overweight from late infancy through mid-childhood (OR 1.01 to 1.02) per week increase in GA. By adolescence, however, GA was slightly negatively associated with the risk of overweight (OR 0.98 [95% CI: 0.97; 1.00], p 0.1) per week of increase in GA. Although based on only four cohorts (n = 32,089) that reached the age of adolescence, data suggest that individuals born very preterm may be at increased odds of overweight (OR 1.46 [95% CI: 1.03; 2.08], p < 0.05) compared with term counterparts. Findings were consistent across cohorts and sensitivity analyses despite considerable heterogeneity in cohort characteristics. However, residual confounding may be a limitation in this study, while findings may be less generalisable to settings in low- and middle-income countries.

CONCLUSIONS

This study based on data from infancy through adolescence from 16 cohort studies found that GA may be important for body size in infancy, but the strength of association attenuates consistently with age. By adolescence, preterm individuals have on average a similar mean BMI to peers born at term.

Preterm birth and subsequent timing of pubertal growth, menarche, and voice break

BACKGROUND

We evaluated pubertal growth and pubertal timing of participants born preterm compared to those born at term.

METHODS

In the ESTER Preterm Birth Study, we collected growth data and measured final height of men/women born very or moderately preterm (<34 gestational weeks, n = 52/55), late preterm (34-<37 weeks, 94/106), and term (≥37 weeks, 131/151), resulting in median 9 measurements at ≥6 years. Timing of menarche or voice break was self-reported. Peak height velocity (PHV, cm/year) and age at PHV (years) were compared with SuperImposition by Translation And Rotation (SITAR) model (sexes separately).

RESULTS

Age at PHV (years) and PHV (cm/year) were similar in all gestational age groups. Compared to term controls, insignificant differences in age at PHV were 0.1 (95% CI: -0.2 to 0.4) years/0.2 (-0.1 to 0.4) for very or moderately/late preterm born men and -0.0 (-0.3 to 0.3)/-0.0 (-0.3 to 0.2) for women, respectively. Being born small for gestational age was not associated with pubertal growth. Age at menarche or voice break was similar in all the gestational age groups.

CONCLUSIONS

Timing of pubertal growth and age at menarche or voice break were similar in participants born preterm and at term.

IMPACT

Pubertal growth and pubertal timing were similar in preterm and term participants in a relatively large cohort with a wide range of gestational ages. Previous literature indicates that small for gestational age is a risk for early puberty in term born children. This was not shown in preterm children. While our study had limited power for children born very preterm, all children born preterm were not at increased risk for early puberty.

Associations between size at birth and size at 6 years among preterm infants: a retrospective cohort study

BACKGROUND

Little is known about the relationship between fetal growth and size at school age in children born prematurely. We evaluated the relationships between gestational age and anthropometric z-scores at birth and size at 6 years of age in very-low-birthweight infants born at <30 weeks' gestation.

METHODS

We collected data from the medical records of 187 preterm children at birth and 6 years of age. We evaluated correlations between gestational age and z-scores for weight, body length, and head circumference at birth and z-scores for weight, height, and body mass index at 6 years of age.

RESULTS

Simple regression analysis showed that, in boys and the overall group, gestational age and z-scores for weight, body length, and head circumference at birth had significant association with z-scores for weight, height, and body mass index at 6 years of age. No significant associations were found in girls, except for weight z-scores at 6 years with gestational age and head circumference z-scores at birth. Multiple regression analysis showed that gestational age and length z-score at birth were significantly and independently associated with weight and height z-score at 6 years. Gestational age was also significantly and independently associated with body mass index z-score at 6 years.

CONCLUSION

Gestational age and fetal growth in length (assessed with the birth-length z-score) were associated with anthropometric z-scores at 6 years in very-low-birthweight children born at <30 weeks of gestation, especially in boys.

Critical examination of relationships between early growth and childhood overweight in extremely preterm infants

OBJECTIVES

To identify the prevalence and risk factors for childhood overweight and obesity (OWO) at 3-year corrected age in children born <1500 g <29 weeks gestation.

STUDY DESIGN

A multicentre retrospective cohort study for preterm infants admitted to neonatal intensive care units between 2001 and 2014.

RESULTS

Data were available for 911 (89.4%) of the 1019 infants who met the inclusion criteria. Of them, 22 (2.4%) had OWO. There were no associations between OWO and being small for gestational age (RR = 1.3, 95% confidence interval (CI): 0.3-5.4) or weight <10th percentile at 36 weeks (RR = 1.1, 95% CI: 0.4-2.8). OWO was associated with low maternal education (RR = 7.4, 95% CI: 2.1-26), maternal diabetes (RR = 5.2, 95% CI: 1.9-15) and neonatal brain injury (RR = 4.9, 95% CI: 1.8-14). Adjusting for concurrent child weight at 3 years of age resulted in an overadjustment bias.

CONCLUSION

Small size at birth or at 36 weeks gestation in extremely preterm infants is not associated with increased risk of early childhood overgrowth or obesity.

CLINICAL TRIAL REGISTRATION

NCT03064022.

Outcomes into adulthood of infants born extremely preterm

As survival of infants born extremely preterm increases, more are now reaching adulthood. It is well documented that survivors born extremely preterm experience more developmental delay and disability in multiple domains compared with term-born controls in early childhood and school age. However, with increasing age, health problems involving physical and mental health become more evident. Despite these challenges, it is reassuring that self-reported quality of life remains good. Future directions of research include development of age-appropriate interventions to optimise health and development of individuals born extremely preterm beyond school age.

Predictors of long-term neurodevelopmental outcomes of children born extremely preterm

Children born extremely preterm (<28 weeks' gestation) are at high risk of a range of adverse neurodevelopmental outcomes in later childhood compared with their peers born at term, including cognitive, motor, and behavioral difficulties. These difficulties can be associated with poorer academic achievement and health outcomes at school age. In this review, we discuss several predictors in the newborn period of early childhood neurodevelopmental outcomes including perinatal risk factors, neuroimaging findings and neurobehavioral assessments, along with social and environmental influences for children born extremely preterm. Given the complexity of predicting long-term outcomes in children born extremely preterm, we recommend multi-disciplinary teams in clinical practice to assist in determining an individual child's risk for adverse long-term outcomes and need for referral to targeted intervention, based upon their risk.

Renal morphology and glomerular capillarisation in young adult sheep born moderately preterm

Preterm birth (delivery <37 weeks of gestation) is associated with impaired glomerular capillary growth in neonates; if this persists, it may be a contributing factor in the increased risk of hypertension and chronic kidney disease in people born preterm. Therefore, in this study, we aimed to determine the long-term impact of preterm birth on renal morphology, in adult sheep. Singleton male sheep were delivered moderately preterm at 132 days (~0.9) of gestation (n = 6) or at term (147 days gestation; n = 6) and euthanised at 14.5 months of age (early adulthood). Stereological methods were used to determine mean renal corpuscle and glomerular volumes, and glomerular capillary length and surface area, in the outer, mid and inner regions of the renal cortex. Glomerulosclerosis and interstitial collagen levels were assessed histologically. By 14.5 months of age, there was no difference between the term and preterm sheep in body or kidney weight. Renal corpuscle volume was significantly larger in the preterm sheep than the term sheep, with the preterm sheep exhibiting enlarged Bowman's spaces; however, there was no difference in glomerular volume between groups, with no impact of preterm birth on capillary length or surface area per glomerulus. There was also no difference in interstitial collagen levels or glomerulosclerosis index between groups. Findings suggest that moderate preterm birth does not adversely affect glomerular structure in early adulthood. The enlarged Bowman's space in the renal corpuscles of the preterm sheep kidneys, however, is of concern and merits further research into its cause and functional consequences.

Impact of very preterm birth and post-discharge growth on cardiometabolic outcomes at school age: a retrospective cohort study

Background

Adverse metabolic outcomes later in life have been reported among children or young adults who were born as preterm infants. This study was conducted to examine the impact of very preterm/very low birth weight (VP/VLBW) birth and subsequent growth after hospital discharge on cardiometabolic outcomes such as insulin resistance, fasting glucose, and systolic and diastolic blood pressure (BP) among children at 6–8 years of age.

Methods

This retrospective cohort study included children aged 6–8 years and compared those who were born at < 32 weeks of gestation or weighing < 1,500 g at birth (n = 60) with those born at term (n = 110). Body size, fat mass, BP, glucose, insulin, leptin, adiponectin, and lipid profiles were measured. Weight-for-age z-score changes between discharge and early school-age period were also calculated, and factors associated with BP, fasting glucose, and insulin resistance were analyzed.

Results

Children who were born VP/VLBW had significantly lower fat masses, higher systolic BP and diastolic BP, and significantly higher values of fasting glucose, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR), compared to children born at term. VP/VLBW was correlated with HOMA-IR and BPs after adjusting for various factors, including fat mass index and weight-for-age z-score changes. Weight-for-age z-score changes were associated with HOMA-IR, but not with BPs.

Conclusions

Although children aged 6–8 years who were born VP/VLBW showed significantly lower weight and fat mass, they had significantly higher BPs, fasting glucose, HOMA-IR, and leptin levels. The associations of VP/VLBW with cardiometabolic factors were independent of fat mass and weight gain velocity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02851-5.

Extremely and very preterm-born children <1500 g show different weight development in childhood compared to their peers

AIM

To develop reference growth charts for body mass index (BMI), weight, length and head circumference in children born extremely preterm (EPT) or very preterm (VPT) with a birth weight <1500 g.

METHODS

We analysed EPT and VPT children from the German Neonatal Network born between 2009 and 2013 without chronic diseases or medications influencing growth. These data of EPT and VPT datasets were split into a training dataset and a validation dataset. In the validation dataset, data from 385 EPT and 491 VPT children from birth to age 6 years were analysed to calculate growth charts.

RESULTS

The percentiles of length of EPT and VPT children were comparable to German reference percentiles. The BMI peak in infancy was attenuated, and BMI was lower in all the EPT and VPT children analysed. From 2 years until 6 years of age, head circumference was lower in EPT and VPT boys and girls.

CONCLUSION

Deficits in height described in EPT cohorts born during the 1980 s and 1990 s were not seen in our cohort. However, EPT and VPT born children showed growth patterns that differed from national reference curves for BMI. The growth charts provided here can be used to judge the growth of EPT and VPT born children.

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

BACKGROUND

Early postanal growth of preterm infants has many effects on early and late health. However, evidence on growth pattern in Chinese preterm infant population during early life is insufficient. This study aims to describe the growth trajectory, catch-up growth, and risk of overweight of preterm infants during the first 2 years of life in a Chinese community population.

METHODS

All preterm infants (n = 10,624) received routine childcare in one primary maternal and child healthcare network in 8 years were included. Body weight and length/height at corrected age (CA) 40 weeks, CA 3 months, 6 months, 9 months, 12 months, 18 months, and 24 months were extracted and converted to z-scores based on the World Health Organization (WHO) standards. According to the intrauterine growth status, infants were divided into small for gestational age (SGA), appropriate for gestational age (AGA), and large for gestational age (LGA) infants. Changes of z-score were used to describe the growth velocity. Generalized estimating equation (GEE) model was used to analyze growth trajectory trends over time.

RESULTS

Body weight and length/height were overall above the WHO standards during the first 2 years of life. Z-score increased significantly by 0.08 (95% CI: 0.06-0.10) in weight and 0.07 (95% CI: 0.04-0.09) in length/height from CA 40 weeks to 3 months and then levelled off until CA 24 months after adjustment. Almost 90% of AGA and LGA infants achieved growth targets (≥25th percentile of WHO standards), and over 85% of SGA infants achieved catch-up growth (≥10th percentile of WHO standards) before CA 24 months. However, the risk of overweight appeared during this period, with the proportion of infants with the risk of overweight being at the peak at CA 3 months (25.6% of all preterm infants and 39.4% of LGA infants). Growth trajectories of SGA showed increasing trends, but those of LGA showed decreasing trends during the first 2 years.

CONCLUSIONS

Body weight and length/height of preterm infants are above the WHO standards in the Chinese community population during the first 2 years of life. Catch-up growth is accompanied by risk of overweight as early as CA 3 months. (349 words).

Extreme prematurity, growth and neurodevelopment at 8 years: a cohort study

OBJECTIVE

Infants born extremely preterm (EP, <28 weeks' gestation) exhibit poorer growth and neurodevelopmental impairment in early childhood compared with their term-born peers. Whether poor growth persists and whether associations of growth with neurodevelopmental functioning have changed in the decades since the introduction of surfactant are not well described. This study aims to (1) compare growth from birth to 2 years then 8 years in children born EP between three different eras, and (2) investigate the associations of growth from birth to 2 years then 8 years with cognitive, academic, executive and motor function at 8 years, and if associations have changed over time.

DESIGN

Prospective observational cohort studies in the State of Victoria, Australia in three discrete eras: 1991-1992, 1997 and 2005. EP children had weight and head circumference measured at birth, and weight, head circumference and height at 2 and 8 years. Cognitive ability, academic performance, executive function and motor skills were assessed at 8 years, corrected for prematurity.

RESULTS

499/546 (91%) of surviving EP children were fully assessed at 8 years. Growth in children born EP did not differ substantially between eras and associations between growth and neurodevelopment did not change over time. Overall, better weight and head growth from birth to 2 years were associated with improved neurodevelopment at 8 years.

CONCLUSIONS

Growth of children born EP has not improved in more recent eras. Better early head and weight growth are associated with improved neurodevelopment in mid-childhood.

Comparison of Postnatal Growth Charts of Singleton Preterm and Term Infants Using World Health Organization Standards at 40-160 Weeks Postmenstrual Age: A Chinese Single-Center Retrospective Cohort Study

There remains controversy regarding whether the growth charts constructed from data of term infants, such as those produced by the World Health Organization (WHO) standards, can appropriately evaluate the postnatal growth of preterm infants. This retrospective cohort study, conducted in the First Affiliated Hospital of Shandong First Medical University in Jinan China, aimed to compare the postnatal growth charts of singleton preterm and term infants using WHO standards at 40-160 weeks postmenstrual age (PMA). A total of 5,459 and 15,185 sets of longitudinal measurements [length/height, weight, head circumference (HC), and body mass index (BMI)] from birth to 160 weeks PMA were used to construct growth charts for 559 singleton preterm (mean PMA at birth, 33.84 weeks) and 1,596 singleton term infants (born at 40 weeks PMA), respectively, using the Generalized Additive Models for Location, Scale, and Shape (GAMLSS) method. Z-scores (prematurity corrected) were calculated using WHO Anthro software. Compared to WHO standards, all parameters of preterm infants were increased, especially in terms of length/height and weight; the gap between the two almost spanned two adjacent centile curves. Compared to term controls, the length/height, weight, and BMI of preterm infants were higher at 40 weeks PMA, surpassed by term infants at 52-64 weeks PMA, and quite consistent thereafter. The HC of preterm infants at 40-160 weeks PMA was quite consistent with both term controls and the WHO standards. The Z-scores for length/height, weight, and BMI of preterm infants relative to the WHO standards gradually decreased from 1.20, 1.13, and 0.74 at 40-44 weeks PMA to 0.67, 0.42, and 0.03 at 132-160 weeks PMA, respectively; Z-scores for HC of preterm infants rapidly decreased from 0.73 to 0.29 at 40-50 weeks PMA, and then fluctuated in the range of 0.08-0.23 at 50-160 weeks PMA. Preterm infants had higher growth trajectories than the WHO standards and similar but not identical trajectories to term infants during the first 2 years of life. These findings reemphasize the necessity of constructing local growth charts for Chinese singleton preterm infants.

Cardiovascular Health Profile at Age 25 Years in Adults Born Extremely Preterm or Extremely Low Birthweight

Being born extremely preterm (EP; <28 weeks' gestation) or extremely low birthweight (ELBW; <1000 g birthweight) may predict increased cardiometabolic risk in adulthood, but other early life predictors are less well described. We aimed to (1) compare cardiovascular health profiles between 165 adults born EP/ELBW and 127 controls at age 25 years, drawn from a prospective longitudinal cohort study, recruited at birth in 1991 to 1992; and (2) in the EP/ELBW group, determine early life associations of cardiovascular health. Cardiovascular health profiles were calculated individually for measures of anthropometry, abdominal visceral fat, blood pressure, fasting plasma glucose, insulin, lipids, C-reactive protein, vascular indices, exercise tolerance and smoking status, and summed for an overall score. Cardiovascular health profiles were compared between groups; using logistic regression (individual scores) and the Mann-Whitney U test (cumulative score). Compared with controls, adults born EP/ELBW had less favorable cardiovascular health profiles; individually for abdominal visceral fat (odds ratio, 0.56 [95% CI, 0.33-0.96], P=0.03), blood pressure (odds ratio 0.38 [95% CI, 0.23-0.63], P<0.001), exercise capacity (odds ratio 0.37 [95% CI, 0.22-0.63], P<0.001), and fasting glucose (odds ratio 0.51 [95% CI, 0.31-0.84], P=0.01) and overall (median [interquartile range] 10 [7-11] versus 11 [9-12], P=0.007). Male sex predicted unfavorable abdominal visceral fat, blood pressure and fasting glucose, and favorable exercise capacity. Greater increases in weight Z scores between 2 and 8, and 8 and 18 years predicted less favorable profiles of exercise capacity and visceral fat. Longer-term follow-up is critical to determine the cardiovascular sequelae of adults born EP/ELBW.

[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.

Impact of extreme prematurity or extreme low birth weight on young adult health and well-being: the Victorian Infant Collaborative Study (VICS) 1991-1992 Longitudinal Cohort study protocol

INTRODUCTION

Infants born extremely preterm (EP, <28 weeks' gestation) or with extremely low birth weight (ELBW,<1000 g) in the era when surfactant has been available clinically are at high risk of health and developmental problems in childhood and adolescence. However, how their health and well-being may be affected in adulthood is not well known. This study aims to compare between EP/ELBW and normal birthweight (NBW) controls: (1) physical health, mental health and socioemotional functioning at 25 years of age and (2) trajectories of these outcomes from childhood to adulthood. In addition, this study aims to identify risk factors in pregnancy, infancy, childhood and adolescence for poor physical health and well-being in EP/ELBW young adults.

METHODS AND ANALYSIS

The Victorian Infant Collaborative Study (VICS) is a prospective geographical cohort of all EP/ELBW survivors to 18 years of age born in the State of Victoria, Australia, from 1 January 1991 to 31 December 1992 (n=297) and contemporaneous term-born/NBW controls (n=262). Participants were recruited at birth and followed up at 2, 5, 8 and 18 years. This 25-year follow-up includes assessments of physical health (cardiovascular, respiratory and musculoskeletal), mental health and socioemotional functioning. Outcomes will be compared between the birth groups using linear and logistic regression, fitted using generalised estimating equations (GEEs). Trajectories of health outcomes from early childhood will be compared between the birth groups using linear mixed-effects models. Risk factors for adult outcomes will be assessed using linear and logistic regression (fitted using GEEs).

ETHICS AND DISSEMINATION

This study was approved by the Human Research Ethics Committees of the Royal Women's Hospital, Mercy Hospital for Women, Monash Medical Centre and the Royal Children's Hospital, Melbourne. Study outcomes will be disseminated through conference presentations, peer-reviewed publications, the internet and social media.

Environmental and birth characteristics as predictors of short stature in early childhood

AIM

To evaluate for environmental and birth characteristic predictors of short stature in a large nationally representative sample.

METHODS

We evaluated 10 127 children from the Early Childhood Longitudinal Study-Kindergarten 2011 cohort, using univariate and multivariable linear and logistic regression to evaluate factors associated with short stature (height <3rd percentile) at kindergarten through second grade. Predictors included birthweight, preterm status, sex, parental education, parental income and race/ethnicity.

RESULTS

Lower birthweight was associated with short stature, with each decreasing kilogram having a 2.45 adjusted odds ratio (aOR; 95% confidence interval [CI] 1.81, 3.33) of short stature for term children in second grade. Preterm children (compared to term children) had an aOR of 2.23 (CI 1.32, 3.78) for short stature. Other predictors of short stature included female sex and lower parental income. African American children had a lower risk of short stature (aOR 0.34, CI 0.14, 0.82) compared to white children.

CONCLUSION

Predictors of short stature include lower birthweight, preterm status, female sex and parental income. Socio-economic disparities and race/ethnicity further influenced height. These data may assist paediatricians in considering contributors to stature outcomes by early school age.

Postnatal growth in preterm infants during the first year of life: A population-based cohort study in China

In preterm infants (i.e. the gestational age less than 37 weeks), postnatal growth remains a concern. This study used multicenter longitudinal data from China's Under 5 Child Nutrition and Health Surveillance System to investigate the postnatal growth in the weight and length of preterm infants. Gender-stratified differences in weight and length were assessed between preterm and term infants. 1221 preterm infants and 1221 matched term infants were included. The rates of growth in weight and length in preterm infants was greater than those in term infants, especially from the first to sixth month. The rates were higher in males compared to females in the first 3 months. The differences of weight and length between preterm and term infants decreased with increasing age, however, these measurements did not reach the level of their term peers until 12 months before adjusting for gestational age. The median values of weight and length were even larger in preterm infants in the first month after adjusting for gestational age.

Metabolic Syndrome in Very Low Birth Weight Young Adults and Controls: The New Zealand 1986 VLBW Study

OBJECTIVE

To assess the physical well-being and components of the metabolic syndrome in a national cohort of very low birth weight (VLBW) young adults and same age controls.

STUDY DESIGN

The New Zealand VLBW Study cohort prospectively included all infants with birth weight <1500 g born in 1986, with 338 (82%) surviving to discharge home. Height and weight were measured at age 7-8 years. The VLBW cohort (n = 229; 71% alive) and term-born controls (n = 100) aged 27-29 years were clinically assessed in a single center over 2 days, including assessment for components of the metabolic syndrome.

RESULTS

Compared with controls, both male and female VLBW adults were significantly shorter (P < .001), but only females were lighter (P < .001) and had lower mean body mass index (P = .044), fat mass, and body fat percentage. Males, but not females, had significantly higher systolic blood pressure (P = .028), but there were no significant differences in other components of the metabolic syndrome. There was no difference in the prevalence of the metabolic syndrome in VLBW adults compared with controls (males, 22.2% vs 11.1%; P = .15: females, 12.8% vs 13.1%; P = .95). Examining the VLBW cohort with logistic regression, male sex, gestational age <28 weeks, Māori/Pacific Island ethnicity, and body mass index >90th percentile at age 7-8 years were significant predictors for the metabolic syndrome at age 27-29 years, with ORs of 2-4.

CONCLUSIONS

Systolic blood pressure in males was the only component of the metabolic syndrome that was significantly elevated in VLBW adults compared with controls. Extreme prematurity (<28 weeks) and body mass index >90th percentile at age 7-8 years were significant predictors of the metabolic syndrome at age 27-29 years.

TRIAL REGISTRATION

Registered at the Australian Clinical Trials Registry: ACTRN12612000995875.

Correcting standardized expiratory flows for prematurity in ex-preterm survivors-Is it necessary?

OBJECTIVE

To determine the effect of correcting for prematurity on standardized values for expiratory flow rates for participants from 5 years through to 70 years of age.

METHODS

In a theoretical model we assumed starting values for expiratory flows that were expected to give ranges within ±2 SD. Keeping expiratory flows, ethnicity and height constant, we then determined how z scores varied between 5 and 16.9 years, and, with two different fixed values for height and expiratory flows, between 16 and 70 years of ages, for both sexes. In a clinical example, we compared expiratory flows with age both corrected and uncorrected for prematurity between 144 survivors born extremely preterm and 141 term-born controls at both 8 and 18 years of age.

RESULTS

In the theoretical models, z scores mostly declined through childhood until the late teenage years, and then began to rise through later life. The maximum difference in z-scores between corrected and uncorrected scores for a participant born 4 months' preterm would occur in the early teenage years, and for the forced vital capacity would be approximately -0.09 SD wider. In the clinical example not correcting for prematurity resulted in a maximum gap between preterm and term cohorts 0.06 SD wider for the forced vital capacity at 8 years than if age was corrected for prematurity.

CONCLUSIONS

Correction for prematurity is not necessary in clinical practice, and is probably not required for research in studies of respiratory airflow through childhood or adulthood.

Earlier achievement of full enteral feeding in extremely low birth weight neonates is not associated with growth improvement in the first 2 years of life

Limiting the number of days until achievement of full enteral feeding in extremely low birth weight neonates (ELBW; < 1000 g) might affect growth in the first years of life. This study compared the Z scores in growth over time of two cohorts of ELBW neonates that were comparable on maternal and neonatal characteristics and characteristics of hospitalization, but differed in enteral feeding strategy during neonatal admission. In the 2010-2014 cohort, full enteral feeding was achieved on average 16 days earlier than in the 2000-2005 cohort. In both cohorts, weight, height, and head circumference were recorded at birth and at the corrected ages of 9 and 24 months. A linear mixed model with repeated measures controlling for neonates small for gestational age showed no significant effect of different strategies in achievement of full enteral feeding on any anthropometric Z scores over time. Although full enteral feeding was achieved earlier in the 2010-2014 cohort, this was not associated with growth patterns during the first two years of life.

CONCLUSION

The effect of a change in strategy to achieve full enteral feeding at an earlier stage in ELBW neonates was assessed. Early enteral feeding strategies do not necessarily improve growth during the first two years of life. What is Known: • Feeding strategies during neonatal stay may affect growth in the first years of life. • Strategies to achieve full enteral feeding earlier were implemented, but data on the impact on subsequent growth after discharge are limited. What is New: • Full enteral feeding was achieved earlier, but this was not associated with improved growth during the first 2 years of life after discharge. • Early enteral feeding strategies do not necessarily improve growth during the first 2 years of life.

Relationship between Epigenetic Maturity and Respiratory Morbidity in Preterm Infants

OBJECTIVE

To assess associations between epigenetic maturity of extremely preterm babies (born at less than 28 weeks of gestation), neonatal interventions, and respiratory outcomes, including the administration of surfactant and postnatal corticosteroids, duration of assisted ventilation, and development of bronchopulmonary dysplasia (BPD).

STUDY DESIGN

DNA was extracted from neonatal blood spots collected after birth from 143 extremely preterm infants born 1991-1992 in Victoria, Australia and used to determined DNA methylation (DNAm). A DNAm based gestational age was determined using our previously published method. The residual of DNAm gestational age and clinically estimated gestational age (referred to as "gestational age acceleration") was used as a measure to assess developmental maturity. Associations between gestational age acceleration and respiratory interventions and morbidities were determined.

RESULTS

Infants with higher gestational age acceleration were less likely to receive surfactant (P = .009) or postnatal corticosteroids (P = .008), had fewer days of assisted ventilation (P = .01), and had less BPD (P = .02). Respiratory measures are known to correlate with gestational age; however, models comparing each with clinically estimated gestational age were improved by the addition of the gestational age acceleration measure in the model.

CONCLUSIONS

Gestational age acceleration correlates with respiratory interventions and outcomes of extremely preterm babies. Surfactant and postnatal corticosteroid use, assisted ventilation days, and BPD rates were all lower in babies who were epigenetically more mature than their obstetrically estimated gestational age. This suggests that gestational age acceleration is a clinically relevant metric of developmental maturity.

Moderate preterm birth affects right ventricular structure and function and pulmonary artery blood flow in adult sheep

KEY POINTS

Preterm birth occurs when the heart muscle is immature and ill-prepared for the changes in heart and lung function at birth. MRI imaging studies show differences in the growth and function of the heart of young adults born preterm, with the effects more pronounced in the right ventricle. The findings of this study, conducted in sheep, showed that following moderate preterm birth the right ventricular wall was thinner in adulthood, with a reduction in the number and size of the heart muscle cells; in addition, there was impaired blood flow in the main artery leading from the right ventricle to the lungs. The findings indicate that being born only a few weeks early adversely affects the cellular structure of the right ventricle and blood flow to the lungs in adulthood. The reduced number of heart muscle cells has the potential to deleteriously affect right ventricular growth potential and function.

ABSTRACT

Preterm birth prematurely exposes the immature heart to the haemodynamic transition at birth, which has the potential to induce abnormal cardiac remodelling. Magnetic resonance imaging studies in young adults born preterm have shown abnormalities in the gross structure of the ventricles (particularly the right ventricle; RV), but the cellular basis of these alterations is unknown. The aim of this study, conducted in sheep, was to determine the effect of moderate preterm birth on RV cellular structure and function in early adulthood. Male singleton lambs were delivered moderately preterm (132 ± 1 days; n = 7) or at term (147 ± 1 days; n = 7). At 14.5 months of age, intra-arterial blood pressure and heart rate were measured. Pulmonary artery diameter and peak systolic blood flow were determined using ultrasound imaging, and RV stroke volume and output calculated. Cardiomyocyte number, size, nuclearity and levels of cardiac fibrosis were subsequently assessed in perfusion-fixed hearts using image analysis and stereological methods. Blood pressure (systolic, diastolic and mean), heart rate, levels of myocardial fibrosis and RV stroke volume and output were not different between groups. There was, however, a significant reduction in RV wall thickness in preterm sheep, and this was accompanied by a significant reduction in peak systolic blood flow in the pulmonary artery and in RV cardiomyocyte number. Cellular changes in the RV wall and reduced pulmonary artery blood flow following preterm birth have the potential to adversely affect cardiac and respiratory haemodynamics, especially when the cardiovascular system is physiologically or pathologically challenged.

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.

Association Between Preterm Birth and Lower Adult Height in Women

We examined whether being born preterm was associated with changes in adult anthropometry in women. We assessed data on 201,382 women (born in 1973-1988) from the Swedish Birth Register. The mean age was 26.0 years. Of the women in our cohort, 663 were born very preterm (<32 weeks of gestation), 8,247 were born moderately preterm (at least 32 weeks but <37 weeks), and 192,472 were born at term (37-41 weeks). Subgroup analyses were carried out among siblings and also after adjustment for maternal anthropometric data. Statistical tests were 2-sided. Decreasing gestational age was associated with lower height (-1.1 mm per week of gestation; P < 0.0001), so that women who were born very preterm were on average 12 mm shorter than women who were born moderately preterm (P < 0.0001) and 17 mm shorter than women born at term (P < 0.0001). Compared with women who were born at term, those who were born very preterm had 2.9 times higher odds of short stature (<155.4 cm), and those born moderately preterm had 1.43 times higher odds. Subgroup analyses showed no differences between women born moderately preterm and those born at term but accentuated differences from women born very preterm. Among siblings (n = 2,388), very preterm women were 23 mm shorter than those born at term (P = 0.003), with a 20-mm difference observed in subgroup analyses (n = 27,395) that were adjusted for maternal stature (P < 0.001). A shorter final height was associated with decreasing gestational age, and this association was particularly marked in women born very preterm.

Growth, metabolic markers, and cognition in 8-year old children born prematurely, follow-up of a randomized controlled trial with essential fatty acids

The study is a follow-up of a randomized, double-blinded, placebo-controlled trial of supplementation with docosahexaenoic acid (DHA) and arachidonic acid (AA) to 129 very low birth weight (VLBW; birth weight <1500 g) infants fed human milk. The main hypothesis was that supplementation would affect growth, metabolic markers, and cognitive function. The secondary aim was to describe predictors of metabolic markers and cognitive status at follow-up. Ninety-eight children met for 8-year follow-up with anthropometric measures, blood biomarkers, and cognitive testing. The intervention group had significantly lower insulin-like growth factor-1 (IGF-1) at 8 years, whereas no differences in growth or intelligence quotient (IQ) were found. For the total cohort, weight gain during first year of life was neither associated with BMI, metabolic markers, nor IQ at follow-up. Blood DHA at 8 years was positively associated with IQ.

CONCLUSIONS

The study is the first long-term follow-up of a randomized controlled trial with essential fatty acids investigating growth, metabolic factors, and IQ. IGF-1 levels were significantly lower in the intervention group at 8 years. First-year growth was not associated with BMI, metabolic markers, or IQ at follow-up. Current DHA status was a significant predictor of higher IQ at follow-up.

WHAT IS KNOWN

• Preterm children have increased risk of lower intelligence quotient (IQ), reduced growth, and abnormal metabolic status. • Early intake of docosahexaenoic acid (DHA) and arachidonic acid (AA), as well as early growth pattern, may influence both IQ and metabolic status. What is New: • Early intervention with DHA and AA led to reduced insulin-like growth factor-1 in blood at 8 years of age. • Weight gain during first year of life was neither associated with impaired metabolic markers nor improved IQ at follow-up. • Current DHA status was a significant predictor of higher IQ at 8 years, also when maternal education and birth weight were included in the model.

Trajectories of length, weight, and bone mineral density among preterm infants during the first 12 months of corrected age in China

Background

Limited evidence has been provided on the trajectories of length, weight, and bone mineral density (BMD) among preterm infants in early life in Asian countries.

Methods

We conducted a longitudinal study, which included 652 late preterm (gestational age: 34–36.9 weeks), 486 moderate preterm (32–33.9), 291 very preterm (28–31.9), 149 extremely preterm infants (≤28.9) and 1434 full-term peers (≥37) during the first 12 months of corrected age in Wuhan, China. Weight and length were measured at birth, once randomly before term, and every month thereafter. BMD was examined at 3, 6, 9 and 12 months using dual-energy X-ray absorptiometry.

Results

From birth to 12 months of corrected age, growth peaks in length and weight were observed at 1–3 months among preterm infants. No catch-up growth in length, weight, and BMD was observed among preterm infants. However, accelerated growth in length, weight, and BMD was found. Among extremely preterm infants, relative to full-term infants, length was −6.77 cm (95 % CI: −7.14, −6.40; P for trend < 0.001) lower during the first 12 months; weight was −1.23 kg (−1.33, −1.13; P for trend < 0.001) lower; and BMD was −0.070 g/cm²(−0.087, −0.053; P for trend < 0.001) lower; however, average growth rates of these measures were higher (Ps < 0.05). Small gestational age and low birth weight were independently associated with lower length, weight, and BMD.

Conclusion

Growth peaks in length and weight among preterm infants were observed at 1–3 months. No catch-up growth in length, weight, and BMD was observed, however, there was accelerated growth in length, weight, and BMD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0396-6) contains supplementary material, which is available to authorized users.

Influence of H-HOPE intervention for premature infants on growth, feeding progression and length of stay during initial hospitalization

OBJECTIVE

To examine whether premature infants receiving the maternally administered H-HOPE (Hospital to Home Transition-Optimizing Premature Infant's Environment) intervention had more rapid weight gain and growth, improved feeding progression and reduced length of hospital stay, compared with controls.

STUDY DESIGN

Premature infants born at 29-34 weeks gestational age and their mothers with at least two social-environmental risk factors were randomly assigned to H-HOPE intervention (n=88) or an attention control (n=94) groups. H-HOPE consists of a 15-min multisensory intervention (Auditory, Tactile, Visual and Vestibular stimuli) performed twice daily prior to feeding plus maternal participatory guidance on preterm infant behavioral cues.

RESULT

H-HOPE group infants gained weight more rapidly over time than infants in the control group and grew in length more rapidly than control infants, especially during the latter part of the hospital stay.

CONCLUSION

For healthy preterm infants, the H-HOPE intervention appears to improve weight gain and length over time from birth to hospital discharge.

Human active X-specific DNA methylation events showing stability across time and tissues

The phenomenon of X chromosome inactivation in female mammals is well characterised and remains the archetypal example of dosage compensation via monoallelic expression. The temporal series of events that culminates in inactive X-specific gene silencing by DNA methylation has revealed a 'patchwork' of gene inactivation along the chromosome, with approximately 15% of genes escaping. Such genes are therefore potentially subject to sex-specific imbalance between males and females. Aside from XIST, the non-coding RNA on the X chromosome destined to be inactivated, very little is known about the extent of loci that may be selectively silenced on the active X chromosome (Xa). Using longitudinal array-based DNA methylation profiling of two human tissues, we have identified specific and widespread active X-specific DNA methylation showing stability over time and across tissues of disparate origin. Our panel of X-chromosome loci subject to methylation on Xa reflects a potentially novel mechanism for controlling female-specific X inactivation and sex-specific dimorphisms in humans. Further work is needed to investigate these phenomena.

Long-term growth and general health for the tiniest or most immature infants

Given the improving survival rates of extremely preterm (EP, gestational age <28 weeks) infants, there is a need to understand their general growth and health outcomes not only in childhood, but also into adulthood. EP children are shorter and lighter compared with term children at term-equivalent age; with time, the weight disadvantage diminishes but the height disadvantage remains relatively unchanged. EP children and young adults also have higher rates of reported health concerns, medical conditions and visual impairment. Hospital readmissions are higher in early childhood, mostly attributed to respiratory illness. Individuals born EP have reduced bone health and are at increased risk for metabolic disorders. Increased rates of conditions such as diabetes or pathological fractures are not reported in the literature, although follow-up studies so far have only tracked EP individuals into young adulthood. Consequently, health care utilization and costs are increased in EP children and young adults. A thorough knowledge of the health risks related to EP birth is essential in planning surveillance and intervention strategies to optimize their health and wellbeing. Despite the increased risk of health problems, EP young adults generally report their quality of life to be similar to that reported in their term counterparts.

Effects of multimicronutrient supplementation during pregnancy on postnatal growth of children under 5 years of age: a meta-analysis of randomized controlled trials

Background

The beneficial effect of antenatal multiple micronutrients supplementation on infant birth outcomes has been proposed by previous meta-analyses. However, their benefits on postnatal health of children have not been summarized. A meta-analysis of randomized controlled trials was conducted to evaluate the effect of maternal multimicronutrient supplementation on postnatal growth of children under 5 years of age.

Methods

We searched both published and ongoing trials through the PubMed, EMBASE, CENTRAL (OVID platform), Web of Science, BIOSIS Previews, Chinese Science Citation Database, Scopus, ProQuest, ClinicalTrials.gov, Chinese Biomedical Database, and WANFANG database for randomized controlled trials. Reference lists of included studies and relevant reviews were also reviewed for eligible studies. Standard mean difference (SMD) was employed as the index for continuous variables by using fixed effects models. Trend analysis by visual inspection was applied to evaluate the change of mean difference of weight and height between the groups over time.

Results

Nine trials (12 titles) from nine different countries were retrieved for analysis. Pooled results showed that antenatal multimicronutrient supplementation increased child head circumference (SMD = 0.08, 95% CI: 0.00–0.15) compared with supplementation with two micronutrient or less. No evidence was found for the benefits of antenatal multimicronutrient supplementation on weight (P = 0.11), height (P = 0.66), weight-for-age z scores (WAZ) (P = 0.34), height-for-age z scores (HAZ) (P = 0.81) and weight-for-height z scores (WHZ) (P = 0.22). A positive effect was found on chest circumference based on two included studies.

Conclusions

Antenatal multimicronutrient supplementation has a significant positive effect on head circumference of children under 5 years. No impact of the supplementation was found on weight, height, WAZ, HAZ and WHZ.

Antenatal and postnatal growth and 5-year cognitive outcome in very preterm infants

OBJECTIVES

To study how antenatal growth affects cognitive outcome in very preterm infants and to determine whether there is an association between growth in any particular time period between birth and 5 years of age and cognitive outcome. Small for gestational age (SGA) and non-SGA infants were analyzed separately, because antenatal growth may affect postnatal growth.

METHODS

Very low birth weight (<1501 g) infants born between 2001 and 2006 and infants born at <32 gestational weeks between 2004 and 2006 who were treated at Turku University Hospital (n = 181) were followed. Weight, length, and head circumference (HC) of the infants were measured at 9 time points between birth and 5 years. The growth was determined as a z score change between measurement points. Cognitive development was assessed at 5 years of age with the Wechsler Preschool and Primary Scales of Intelligence-Revised. The association between growth and full-scale IQ (FSIQ) was studied.

RESULTS

Growth in length and height was not associated with 5-year cognitive outcome. However, weight (r = 0.18, P = .04) and HC growth (r = 0.25, P = .01) between birth and 2 years of corrected age correlated to FSIQ in non-SGA children. In SGA children, HC growth (r = 0.33, P = .03) around term age correlated to FSIQ.

CONCLUSIONS

Cognitive outcome was similar in SGA and non-SGA very preterm infants. Growth affected cognition positively in both subgroups, but the critical time period was different.