Late preterm infants have worse 24-month neurodevelopmental outcomes than term infants

Developmental Outcomes of Late Preterm Infants From Infancy to Kindergarten

OBJECTIVE

To compare developmental outcomes of late preterm infants (34-36 weeks' gestation) with infants born at early term (37-38 weeks' gestation) and term (39-41 weeks' gestation), from infancy through kindergarten.

METHODS

Sample included 1000 late preterm, 1800 early term, and 3200 term infants ascertained from the Early Childhood Longitudinal Study, Birth Cohort. Direct assessments of development were performed at 9 and 24 months by using the Bayley Short Form-Research Edition T-scores and at preschool and kindergarten using the Early Childhood Longitudinal Study, Birth Cohort reading and mathematics θ scores. Maternal and infant characteristics were obtained from birth certificate data and parent questionnaires. After controlling for covariates, we compared mean developmental outcomes between late preterm and full-term groups in serial cross-sectional analyses at each timepoint using multilinear regression, with pairwise comparisons testing for group differences by gestational age categories.

RESULTS

With covariates controlled at all timepoints, at 9 months late preterm infants demonstrated less optimal developmental outcomes (T = 47.31) compared with infants born early term (T = 49.12) and term (T = 50.09) (P < .0001). This association was not seen at 24 months, (P = .66) but reemerged at preschool. Late preterm infants demonstrated less optimal scores in preschool reading (P = .0006), preschool mathematics (P = .0014), and kindergarten reading (P = .0007) compared with infants born at term gestation.

CONCLUSIONS

Although late preterm infants demonstrate comparable developmental outcomes to full-term infants (early term and full-term gestation) at 24 months, they demonstrate less optimal reading outcomes at preschool and kindergarten timepoints. Ongoing developmental surveillance for late preterm infants is warranted into preschool and kindergarten.

Predictors of Poor School Readiness in Children Without Developmental Delay at Age 2

BACKGROUND AND OBJECTIVES

Current recommendations emphasize developmental screening and surveillance to identify developmental delays (DDs) for referral to early intervention (EI) services. Many young children without DDs, however, are at high risk for poor developmental and behavioral outcomes by school entry but are ineligible for EI. We developed models for 2-year-olds without DD that predict, at kindergarten entry, poor academic performance and high problem behaviors.

METHODS

Data from the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B), were used for this study. The analytic sample excluded children likely eligible for EI because of DDs or very low birth weight. Dependent variables included low academic scores and high problem behaviors at the kindergarten wave. Regression models were developed by using candidate predictors feasibly obtainable during typical 2-year well-child visits. Models were cross-validated internally on randomly selected subsamples.

RESULTS

Approximately 24% of all 2-year-old children were ineligible for EI at 2 years of age but still had poor academic or behavioral outcomes at school entry. Prediction models each contain 9 variables, almost entirely parental, social, or economic. Four variables were associated with both academic and behavioral risk: parental education below bachelor's degree, little/no shared reading at home, food insecurity, and fair/poor parental health. Areas under the receiver-operating characteristic curve were 0.76 for academic risk and 0.71 for behavioral risk. Adding the mental scale score from the Bayley Short Form-Research Edition did not improve areas under the receiver-operating characteristic curve for either model.

CONCLUSIONS

Among children ineligible for EI services, a small set of clinically available variables at age 2 years predicted academic and behavioral outcomes at school entry.

Diabetes in Pregnancy and Childhood Cognitive Development: A Systematic Review

CONTEXT

The effect of diabetes during pregnancy on the cognitive development of offspring is unclear because of inconsistent findings from limited studies.

OBJECTIVE

This review was aimed to provide the best available scientific evidence on the associations between maternal pregnancy diabetes and the cognitive development of offspring.

DATA SOURCES

A search was conducted in the Embase, CINAHL, PubMed, PsycINFO, and Scopus databases.

STUDY SELECTION

Studies addressing the cognitive development of offspring (aged ≤12 years) as outcome and any diabetes in pregnancy as an exposure were included.

DATA EXTRACTION

Data were extracted and evaluated for quality by 2 independent reviewers.

RESULTS

Fourteen articles were eligible for the review. Ten studies investigated the associations between maternal pregestational diabetes or both pregestational and gestational diabetes and offspring's cognitive development; 6 studies found at least 1 negative association. Four studies exclusively examined the relationships between gestational diabetes and offspring's cognitive development; 2 studies found a negative association, 1 a positive association, and 1 a null association. The use of diverse cognitive and diabetes assessment tools/criteria, as well as statistical power, contributed to the inconsistent findings.

LIMITATIONS

The English-language restriction and publication bias in the included studies are potential limitations.

CONCLUSIONS

Although there are few data available regarding the associations between maternal pregnancy diabetes and offspring's cognitive development, this review found that maternal diabetes during pregnancy seems to be negatively associated with offspring's cognitive development. Large prospective studies that address potential confounders are needed to confirm the independent effect of maternal diabetes during pregnancy.

Long-term cognitive and school outcomes of late-preterm and early-term births: a systematic review

BACKGROUND

Children born before full term (39-41 weeks' gestation) are at increased risk of adverse cognitive outcomes. Risk quantification is important as late-preterm (LPT; 34-36 weeks) and early-term (ET; 37-38 weeks) births are common.

METHOD

This review analyses the effect of LPT and ET births on long-term cognitive and educational outcomes. The primary outcome was general cognitive ability. Secondary outcomes included verbal/non-verbal intelligence quotient, subject-specific school performance and special educational needs. The search strategy included Medline and Embase from January 1975 to June 2013. Eligible studies investigated specified outcomes and included suitable gestational age participants assessed at 2 years and older. Outcome measures and socio-demographic descriptors were extracted, and data meta-analysed where possible.

RESULTS

Eight studies compared ET birth with full-term birth. Fourteen studies compared LPT birth with either term birth (>37 weeks, n = 12 studies) or full-term birth (39-41 weeks, n = 2 studies). Substantial between-study heterogeneity existed. LPT and ET children underperformed in most outcomes compared with their term/full-term counterparts, respectively. For example, LPT children had an increased risk of lower general cognitive ability (adjusted risk ratio 1.38 [95% confidence interval 1.06-1.79]), and full-term children performed 5% of a standard deviation higher (z-score 0.05 [0.02, 0.08]) than ET children. Poorer outcomes persist into adulthood; term cohorts performed 5% of a standard deviation higher than LPT cohorts (z-score 0.05 [0.04, 0.07]), and full-term cohorts performed 3% of a standard deviation higher than ET cohorts (z-score 0.03 [0.02, 0.04]).

CONCLUSION

This review critically examines the knowledge around long-term cognitive outcomes of LPT and ET births, demonstrating multiple, small, adverse differences between LPT/ET and term/full-term births.

Delayed growth, motor function and learning in preterm pigs during early postnatal life

Preterm birth interrupts normal fetal growth with consequences for postnatal growth and organ development. In preterm infants, many physiological deficits adapt and disappear with advancing postnatal age, but some may persist into childhood. We hypothesized that preterm birth would induce impaired organ growth and function during the first postnatal week in pigs, while motor abilities and behavioral characteristics would show more persistent developmental delay. Cesarean-delivered preterm ( n = 112, 90% gestation) or term ( n = 56, 100% gestation) piglets were reared under identical conditions and euthanized for blood and organ collection on postnatal days 0, 5, or 26. Body weight gain remained lower in preterm vs. term pigs up to day 26 (25.5 ± 1.5 vs. 31.0 ± 0.5 g·kg−1·day−1, P < 0.01) when relative weights were higher for brain and kidneys and reduced for liver and spleen. Neonatal preterm pigs had reduced values for blood pH, Po2, glucose, lactate, hematocrit, and cortisol, but at day 26, most values were normalized, although plasma serotonin and IGF 1 levels remained reduced. Preterm pigs showed delayed neonatal arousal and impaired physical activity, coordination, exploration, and learning, relative to term pigs (all P < 0.05). Supplementation of parenteral nutrition during the first 5 days with an enteral milk diet did not affect later outcomes. In preterm pigs, many physiological characteristics of immaturity disappeared by 4 wk, while some neurodevelopmental deficits remained. The preterm pig is a relevant animal model to study early dietary and pharmacological interventions that support postnatal maturation and neurodevelopment in preterm infants.

Mono-(2-Ethylhexyl) Phthalate Promotes Pro-Labor Gene Expression in the Human Placenta

Women exposed to phthalates during pregnancy are at increased risk for delivering preterm, but the mechanism behind this relationship is unknown. Placental corticotropin-releasing hormone (CRH) and cyclooxygenase-2 (COX-2) are key mediators of parturition and are regulated by the non-canonical NF-kB (RelB/p52) signaling pathway. In this study, we demonstrate that one of the major phthalate metabolites, mono-(2-ethylhexyl)-phthalate (MEHP), increased CRH and COX-2 mRNA and protein abundance in a dose-dependent manner in primary cultures of cytotrophoblast. This was coupled with an increase in nuclear import of RelB/p52 and its association with the CRH and COX-2 promoters. Silencing of NF-kB inducing kinase, a central signaling component of the non-canonical NF-kB pathway, blocked MEHP-induced upregulation of CRH and COX-2. These results suggest a potential mechanism mediated by RelB/p52 by which phthalates could prematurely induce pro-labor gene activity and lead to preterm birth.

Association between Apnea of Prematurity and Respiratory Distress Syndrome in Late Preterm Infants: An Observational Study

BACKGROUND

Late preterm infants (34-36 weeks' gestation) remain a population at risk for apnea of prematurity (AOP). As infants affected by respiratory distress syndrome (RDS) have immature lungs, they might also have immature control of breathing. Our hypothesis is that an association exists between RDS and AOP in late preterm infants.

OBJECTIVE

The primary objective of this study was to assess the association between RDS and AOP in late preterm infants. The secondary objective was to evaluate if an association exists between apparent RDS severity and AOP.

METHODS

This retrospective observational study was realized in a tertiary care center between January 2009 and December 2011. Data from late preterm infants who presented an uncomplicated perinatal evolution, excepted for RDS, were reviewed. Information related to AOP and RDS was collected using the medical record. Odds ratios were calculated using a binary logistic regression adjusted for gestational age and sex.

RESULTS

Among the 982 included infants, 85 (8.7%) had an RDS diagnosis, 281 (28.6%) had AOP diagnosis, and 107 (10.9%) were treated with caffeine for AOP. There was a significant association between AOP treated with caffeine and RDS for all infants (OR = 3.3, 95% CI: 2.0-5.7). There was no association between AOP and RDS in 34 weeks infants [AOR: 1.6 (95% CI: 0.7-3.8)], but an association remains for 35 [AOR: 5.7 (95% CI: 2.5-13.4)] and 36 [OR = 7.8 (95% CI: 3.2-19.4)] weeks infants. No association was found between apparent RDS severity and AOP, regarding mean oxygen administration duration or complications associated with RDS.

CONCLUSION

The association between RDS and AOP in late preterm infants reflects that patients affected by RDS are not only presenting lung immaturity but also respiratory control immaturity. Special consideration should be given before discontinuing monitoring after RDS resolution in those patients.

Prevalence of suspected developmental delays in early infancy: results from a regional population-based longitudinal study

Background

Prevalence estimates on suspected developmental delays (SDD) in young infants are scarce and a necessary first step for planning an early intervention. We investigated the prevalence of SDD at 4, 6 and 12 months, in addition to associations of SDD with gender, prematurity and maternal education.

Methods

This study is based on a Norwegian longitudinal sample of 1555 infants and their parents attending well-baby clinics for regular health check-ups. Moreover, parents completed the Norwegian translation of the Ages and Stages Questionnaires (ASQ) prior to the check-up, with a corrected gestational age being used to determine the time of administration for preterm infants. Scores ≤ the established cut-offs in one or more of the five development areas: communication, gross motor, fine motor, problem solving and personal-social, which defined SDD for an infant were reported. Chi-square tests were performed for associations between the selected factors and SDD.

Results

According to established Norwegian cut-off points, the overall prevalence of SDD in one or more areas was 7.0 % (10.3 % US cut-off) at 4 months, 5.7 % (12.3 % US cut-off) at 6 months and 6.1 % (10.3 % US cut-off) at 12 months. The highest prevalence of SDD was in the gross motor area at all three time points. A gestational age of < 37 weeks revealed a significant association with the communication SDD at 4 months, and with the fine motor and personal social SDD at 6 months. Gender was significantly associated with the fine motor and problem solving SDD at 4 months and personal- social SDD at 6 months: as more boys than girls were delayed. No significant associations were found between maternal education and the five developmental areas of the ASQ.

Conclusion

Our findings indicate prevalence rates of SDD between 5.7 and 7.0 % in Norwegian infants between 4 and 12 months of age based on the Norwegian ASQ cut-off points (10.3–12.3 %, US cut-off points). During the first year of life, delay is most frequent within the gross motor area. Special attention should be paid to infants born prematurely, as well as to boys. Separate norms for boys and girls should be considered for the ASQ.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0528-z) contains supplementary material, which is available to authorized users.

Neonatal outcomes and delivery of care for infants born late preterm or moderately preterm: a prospective population-based study

OBJECTIVE

To describe neonatal outcomes and explore variation in delivery of care for infants born late (34-36  weeks) and moderately (32-33 weeks) preterm (LMPT).

DESIGN/SETTING

Prospective population-based study comprising births in four major maternity centres, one midwifery-led unit and at home between September 2009 and December 2010. Data were obtained from maternal and neonatal records.

PARTICIPANTS

All LMPT infants were eligible. A random sample of term-born infants (≥37 weeks) acted as controls.

OUTCOME MEASURES

Neonatal unit (NNU) admission, respiratory and nutritional support, neonatal morbidities, investigations, length of stay and postnatal ward care were measured. Differences between centres were explored.

RESULTS

1146 (83%) LMPT and 1258 (79% of eligible) term-born infants were recruited. LMPT infants were significantly more likely to receive resuscitation at birth (17.5% vs 7.4%), respiratory (11.8% vs 0.9%) and nutritional support (3.5% vs 0.3%) and were less likely to be fed breast milk (64.2% vs 72.2%) than term infants. For all interventions and morbidities, a gradient of increasing risk with decreasing gestation was evident. Although 60% of late preterm infants were never admitted to a NNU, 83% required medical input on postnatal wards. Clinical management differed significantly between services.

CONCLUSIONS

LMPT infants place high demands on specialist neonatal services. A substantial amount of previously unreported specialist input is provided in postnatal wards, beyond normal newborn care. Appropriate expertise and planning of early care are essential if such infants are managed away from specialised neonatal settings. Further research is required to clarify optimal and cost-effective postnatal management for LMPT babies.

Transactional processes in children born preterm: Influences of mother-child interactions and parenting stress

This prospective, longitudinal study examined the transactional relations among perceived maternal parenting stress, maternal insensitivity, and child behavior across toddlerhood through age 6 within families of a child born preterm. A sample of 173 mother-child dyads were followed from just before the infant was discharged from the neonatal intensive care unit to 6 years of age, with observational measurements of maternal insensitivity and child noncompliance (24 and 36 months), maternal self-reports of perceived parenting stress (24 months, 36 months, 6 years), and maternal reports of child externalizing behavior at 6 years. Results indicated that maternal insensitivity at 36 months significantly mediated the relation between parenting stress at 24 months and externalizing behaviors at 6 years. Parenting stress was also directly associated with child noncompliance at 36 months and with child externalizing behavior at 6 years. Neonatal risk was associated with increased maternal insensitivity at 24 months, but also decreased parenting stress at 24 months. No significant "child effects" from child behavior to either maternal insensitivity or parenting stress were found. Parenting stress appears to play a critical role for children born preterm, and it is associated with children's behavior both directly and through its influence on parenting. The role of neonatal risk needs continued investigation, as families traditionally considered to be at lower risk may still face significant challenges.

Randomised trial of neonatal hypoglycaemia prevention with oral dextrose gel (hPOD): study protocol

Background

Neonatal hypoglycaemia is common, affecting up to 15 % of newborn babies and 50 % of those with risk factors (preterm, infant of a diabetic, high or low birthweight). Hypoglycaemia can cause brain damage and death, and babies born at risk have an increased risk of developmental delay in later life.

Treatment of hypoglycaemia usually involves additional feeding, often with infant formula, and admission to Neonatal Intensive Care for intravenous dextrose. This can be costly and inhibit the establishment of breast feeding.

Prevention of neonatal hypoglycaemia would be desirable, but there are currently no strategies, beyond early feeding, for prevention of neonatal hypoglycaemia. Buccal dextrose gel is safe and effective in treatment of hypoglycaemia. The aim of this trial is to determine whether 40 % dextrose gel given to babies at risk prevents neonatal hypoglycaemia and hence reduces admission to Neonatal Intensive Care.

Methods/design

Design: Randomised, multicentre, placebo controlled trial.

Inclusion criteria: Babies at risk of hypoglycaemia (preterm, infant of a diabetic, small or large), less than 1 h old, with no apparent indication for Neonatal Intensive Care Unit admission and mother intends to breastfeed.

Trial entry & randomisation: Eligible babies of consenting parents will be allocated by online randomisation to the dextrose gel group or placebo group, using a study number and corresponding trial intervention pack.

Study groups: Babies will receive a single dose of 0.5 ml/kg study gel at 1 h after birth; either 40 % dextrose gel (200 mg/kg) or 2 % hydroxymethylcellulose placebo. Gel will be massaged into the buccal mucosal and followed by a breast feed.

Primary study outcome: Admission to Neonatal Intensive Care.

Sample size: 2,129 babies are required to detect a decrease in admission to Neonatal Intensive Care from 10–6 % (two-sided alpha 0.05, 90 % power, 5 % drop-out rate).

Discussion

This study will investigate whether admission to Neonatal Intensive Care can be prevented by prophylactic oral dextrose gel; a simple, cheap and painless intervention that requires no special expertise or equipment and hence is applicable in almost any birth setting.

Trial registration

Australian New Zealand Clinical Trials Registry - ACTRN 12614001263684.

Late Preterm Infants and Neurodevelopmental Outcomes at Kindergarten

BACKGROUND AND OBJECTIVE

Late preterm infants (LPIs) (gestation 34 weeks and 0 days to 36 weeks and 6 days) compared with full-term infants (FTIs) are at increased risk for mortality and short- and long-term morbidity. The objective of this study was to assess the neurodevelopmental outcomes in a longitudinal cohort study of LPIs from infancy to school age and determine predictive values of earlier developmental testing compared with school-age testing.

METHODS

We used general estimating equations to calculate the odds of school readiness in a nationally representative cohort of 4900 full-term and 950 late preterm infants. We generated positive and negative predictive values of the ability of the 24-month Mental Developmental Index (MDI) scores of the Bayley Short Form, Research Edition, to predict Total School Readiness Score (TSRS) at kindergarten age.

RESULTS

In multivariable analysis, late preterm infants had higher odds of worse TSRSs (adjusted odds ratio 1.52 [95% confidence interval 1.06-2.18], P = .0215). The positive predictive value of a child having an MDI of <70 at 24 months and a TSRS <5% at kindergarten was 10.4%. The negative predictive value of having an MDI of >70 at 24 months and a TSRS >5% was 96.8%. Most infants improved score ranking over the study interval.

CONCLUSIONS

LPIs continue to be delayed at kindergarten compared with FTIs. The predictive validity of having a TSRS in the bottom 5% given a MDI <70 at 24 months was poor. A child who tested within the normal range (>85) at 24 months had an excellent chance of testing in the normal range at kindergarten.

Macro preemies: no thresholds for risks or concerns

PURPOSE OF REVIEW

To provide an overview of the literature regarding medical and developmental risks for moderate to late preterm infants (32-36 weeks gestation), with particular attention to the pediatrician's role in care during both inpatient and outpatient periods.

RECENT FINDINGS

Although the risks of medical issues and developmental delays decrease with increasing gestational age, research suggests that infants born after 32 weeks' gestation often exhibit significant morbidities associated with prematurity. These infants, often referred to as 'macro preemies', have been found to be at a greater risk for medical complications secondary to immature organ systems including impairments in temperature regulation, respiratory functioning, feeding coordination, bilirubin excretion, glucose control, and infection susceptibility. Recent studies of macro preemies also suggest a higher incidence of significant deficits noted in gross and fine motor skills, speech and communication, and learning and behavior compared to their full-term counterparts. Without careful attention from birth, macro preemie infants could be susceptible to both medical issues and developmental delays.

SUMMARY

Physicians should be aware of the research regarding increased medical and developmental risks for all infants born before term in order to provide their patients with comprehensive medical and neurodevelopmental follow-up care.

ADHD and developmental speech/language disorders in late preterm, early term and term infants

OBJECTIVE

We sought to compare the long-term neurodevelopmental outcomes of late preterm, early term and term infants while controlling for a wide range of maternal complications and comorbidities.

STUDY DESIGN

Data for the study was obtained from the South Carolina Medicaid claims and vital records databases from 1 January 2000 to 31 December 2003. We included infants weighing between 1500 and 4500 g, born between 34 0/7 and 41 6/7 weeks, and with no congenital anomalies. Outcome measures were based on the presence of ICD-9-CM codes for attention deficit hyperactivity disorders and developmental speech or language disorders.

RESULT

A total of 3270 late preterm (LPIs), 11,527 early term (ETIs) and 24,005 term infants met the eligibility criteria. Rates for all outcome variables were statistically significant and elevated for LPI, but adjusted hazard ratios (AHRs) were only significant for the risk of developmental speech and/or language delay (LPI: AHR 1.36 95% confidence interval (CI) 1.23 to 1.50; ETI: AHR 1.27 95% CI 1.17 to 1.37).

CONCLUSION

Late preterm and early term deliveries have adverse long-term neurodevelopmental outcomes, and these outcomes should be considered when determining the timing of delivery.

Is the increased risk of preterm birth following excision for cervical intraepithelial neoplasia restricted to the first birth post treatment?

OBJECTIVE

To explore whether the increased risk of preterm birth following treatment for cervical disease is limited to the first birth following colposcopy.

DESIGN

Nested case-control study.

SETTING

Twelve NHS hospitals in England.

POPULATION

All nonmultiple births from women selected as cases or controls from a cohort of women with both colposcopy and a hospital birth. Cases had a preterm (20-36 weeks of gestation) birth. Controls had a term birth (38-42 weeks) and no preterm.

METHODS

Obstetric, colposcopy and pathology details were obtained.

MAIN OUTCOME MEASURES

Adjusted odds ratio of preterm birth in first and second or subsequent births following treatment for cervical disease.

RESULTS

A total of 2798 births (1021 preterm) from 2001 women were included in the analysis. The risk of preterm birth increased with increasing depth of treatment among first births post treatment [trend per category increase in depth, categories <10 mm, 10-14 mm, 15-19 mm, ≥20 mm: odds ratio (OR) 1.23, 95% confidence interval (95% CI) 1.12-1.36, P < 0.001] and among second and subsequent births post treatment (trend OR 1.34, 95% CI 1.15-1.56, P < 0.001). No trend was observed among births before colposcopy (OR 0.98, 95% CI 0.83-1.16, P = 0.855). The absolute risk of a preterm birth following deep treatments (≥15 mm) was 6.5% among births before colposcopy, 18.9% among first births and 17.2% among second and subsequent births post treatment. Risk of preterm birth (once depth was accounted for) did not differ when comparing first births post colposcopy with second and subsequent births post colposcopy (adjusted OR 1.15, 95% CI 0.89-1.49).

CONCLUSIONS

The increased risk of preterm birth following treatment for cervical disease is not restricted to the first birth post colposcopy; it remains for second and subsequent births. These results suggest that once a woman has a deep treatment she remains at higher risk of a preterm birth throughout her reproductive life.

Neurodevelopmental outcomes following late and moderate prematurity: a population-based cohort study

OBJECTIVE

There is a paucity of data relating to neurodevelopmental outcomes in infants born late and moderately preterm (LMPT; 32(+0)-36(+6) weeks). This paper present the results of a prospective, population-based study of 2-year outcomes following LMPT birth.

DESIGN

1130 LMPT and 1255 term-born children were recruited at birth. At 2 years corrected age, parents completed a questionnaire to assess neurosensory (vision, hearing, motor) impairments and the Parent Report of Children's Abilities-Revised to identify cognitive impairment. Relative risks for adverse outcomes were adjusted for sex, socio-economic status and small for gestational age, and weighted to account for over-sampling of term-born multiples. Risk factors for cognitive impairment were explored using multivariable analyses.

RESULTS

Parents of 638 (57%) LMPT infants and 765 (62%) controls completed questionnaires. Among LMPT infants, 1.6% had neurosensory impairment compared with 0.3% of controls (RR 4.89, 95% CI 1.07 to 22.25). Cognitive impairments were the most common adverse outcome: LMPT 6.3%; controls 2.4% (RR 2.09, 95% CI 1.19 to 3.64). LMPT infants were at twice the risk for neurodevelopmental disability (RR 2.19, 95% CI 1.27 to 3.75). Independent risk factors for cognitive impairment in LMPT infants were male sex, socio-economic disadvantage, non-white ethnicity, preeclampsia and not receiving breast milk at discharge.

CONCLUSIONS

Compared with term-born peers, LMPT infants are at double the risk for neurodevelopmental disability at 2 years of age, with the majority of impairments observed in the cognitive domain. Male sex, socio-economic disadvantage and preeclampsia are independent predictors of low cognitive scores following LMPT birth.

Brain damage of the preterm infant: new insights into the role of inflammation

Epidemiological studies have shown a strong association between perinatal infection/inflammation and brain damage in preterm infants and/or neurological handicap in survivors. Experimental studies have shown a causal effect of infection/inflammation on perinatal brain damage. Infection including inflammatory factors can disrupt programmes of brain development and, in particular, induce death and/or blockade of oligodendrocyte maturation, leading to myelin defects. Alternatively, in the so-called multiple-hit hypothesis, infection/inflammation can act as predisposing factors, making the brain more susceptible to a second stress (sensitization process), such as hypoxic-ischaemic or excitotoxic insults. Epidemiological data also suggest that perinatal exposure to inflammatory factors could predispose to long-term diseases including psychiatric disorders.

Behaviour and development in 24-month-old moderately preterm toddlers

OBJECTIVE

Moderately preterm children (gestational age 32-36+6 weeks) are at risk of cognitive and behaviour problems at school age. The aim of this study was to investigate if these problems are already present at the age of 2 years.

STUDY DESIGN

Developmental outcome was assessed at 24-months (corrected age) with the Bayley-III-NL in 116 moderately preterm (M=34.66 ± 1.35 weeks gestation) and 99 term born children (M=39.45 ± 0.98 weeks gestation). Behaviour problems were assessed with the Child Behaviour Checklist.

RESULTS

With age corrected for prematurity, moderately preterm children scored below term peers on Receptive Communication skills (11.05 ± 2.58 vs 12.02 ± 2.74, p=0.02). Without correcting age for prematurity, moderately preterm children scored below term born peers on Cognition (8.97 ± 2.11 vs 10.68 ± 2.35, p<0.001), Fine Motor (10.33 ± 2.15 vs 11.96 ± 2.15, p<0.001), Gross Motor (8.47 ± 2.55 vs 9.39±2.80, p=0.05), Receptive Communication (10.09 ± 2.48 vs 12.02 ± 2.74, p<0.001) and Expressive Communication (10.33 ± 2.43 vs 11.49 ± 2.51, p=0.005) skills. Compared with term peers, more moderately preterm children showed a (mild) delay (ie, scaled score <7) in gross motor skills with age uncorrected for prematurity (20.7% vs 11.2%, p=0.04). Moderately preterm children had more internalising behaviour problems than term children (44.76 ± 8.94 vs 41.54 ± 8.56, p=0.03). No group differences were found in percentages of (sub)clinical scores.

CONCLUSIONS

At the age of 2 years, uncorrected for prematurity, differences in cognition, communication, and motor development were present in moderately preterm children compared with term born peers. After correcting age for prematurity, a difference was only found for receptive communication skills. In addition, moderately preterm children show more internalising behaviour problems.

Gestational age and developmental risk in moderately and late preterm and early term infants

OBJECTIVES

The objective of this study was to evaluate the association between gestational age (GA) at birth and risk of developmental delay at 8 and 18 months of corrected postnatal age.

METHODS

During 2008 to 2011, infants at a corrected postnatal age of 8 or 18 months attending health centers in Santiago, Chile, were recruited. Participants completed a form on biographical and demographic characteristics and the Chilean validated version of the Ages and Stages Questionnaires, Third Edition (ASQ). Logistic regression was used to detect the capacity of GA to predict scores < -2 SDs on the basis of the Chilean ASQ reference group, in at least 1 ASQ domain, adjusted by different control variables.

RESULTS

A total of 1667 infants were included in the analysis. An inverse "dose response" relationship between developmental delay risk and GA at birth was found, both in the crude and adjusted models. Compared with those born full term, the odds ratio for developmental delay risk was 1.56 for those born early term (95% confidence interval [CI]: 1.19-2.06), 2.58 for infants born late preterm (95%CI: 1.66-4.01), and 3.01 for those born moderately preterm (95%CI: 1.59-5.71).

CONCLUSIONS

An inverse dose-response relationship between GA and risk of developmental delay was found in the tested population. Future prospective studies and predictive models are needed to understand whether this higher developmental risk in moderately and late preterm infants is transient and modifiable or persists throughout life, allowing for better targeting of early-intervention strategies.

Effect of early intervention on premature infants' general movements

This study is to investigate the characteristics of premature infants' general movements (GMs) and the effect of early intervention on their GMs.

METHODS

The survey was carried among 285 premature infants. (1) Before intervention, the correlation between the gestational age/ birth weight and the GMs was evaluated. (2) The cases were divided into early intervention group (n=145) and control group (n=140), each group was divided into <32 weeks, 32-34 weeks and >34 weeks group according to gestational age. The early intervention was begun at the 3rd day after birth to 54th week gestational age. The rate of GMs among each group was compared after intervention.

RESULTS

(1) Before intervention, gestational age/birth weight was negatively correlated with the rate of cramped-synchronized (CS) (r=-0.988, r=-0.95, p<0.01), while no correlation with the rate of poor repertoire (PR) (r=0.122, r=0.168, p>0.05). (2) After intervention, for the writhing movement, there was no significant difference (χ2=0.509, 1.401, 0.519, p>0.05) between the early intervention group and the control group. Nevertheless, for the fidgety movement, there was significant difference (χ2=7.921, χ2=5.763, p<0.05) between the two groups, especially in <32 weeks group (χ2=5.578, 4.067 p<0.05) and in >34 weeks group (χ2=5.757, p<0.05).

CONCLUSIONS

(1) It shows that the lower birth weight or the younger delivery gestational age, the more abnormal GMs in premature infants. (2) Early intervention could improve the fidgety movements of premature infant.

Late preterm birth and neurocognitive performance in late adulthood: a birth cohort study

OBJECTIVES

We studied if late preterm birth (34 weeks 0 days-36 weeks 6 days of gestation) is associated with performance on the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Battery (CERAD-NB) in late adulthood and if maximum attained lifetime education moderated these associations.

METHODS

Participants were 919 Finnish men and women born between 1934 and 1944, who participated in the Helsinki Birth Cohort Study. They underwent the CERAD-NB at a mean age of 68.1 years. Data regarding gestational age (late preterm versus term) were extracted from hospital birth records, and educational attainment data were gathered from Statistics Finland.

RESULTS

After adjustment for major confounders, those born late preterm scored lower on word list recognition (mean difference: -0.33 SD; P = .03) than those born at term. Among those who had attained a basic or upper secondary education, late preterm birth was associated with lower scores on word list recognition, constructional praxis, constructional praxis recall, clock drawing, Mini-Mental State Examination, and memory total and CERAD total 2 compound scores (mean differences: >0.40 SD; P values <.05), and had a 2.70 times higher risk of mild cognitive impairment (Mini-Mental State Examination score: <26 points) (P = .02). Among those with tertiary levels of education, late preterm birth was not associated with CERAD-NB scores.

CONCLUSIONS

Our findings offer new insight into the lifelong consequences of late preterm birth, and they add late preterm birth as a novel risk factor to the list of neurocognitive impairment in late adulthood. Our findings also suggest that attained lifetime education may mitigate aging-related neurocognitive impairment, especially among those born late preterm.

Differential effects of parenting in preterm and full-term children on developmental outcomes

OBJECTIVE

To examine the relations between preterm birth, parenting behavior during early childhood, cognitive development, and social-emotional outcomes at Kindergarten entry, and to determine whether parenting behavior differentially influences this developing system in children born preterm compared to children born full-term.

METHODS

The nationally representative sample comprised 3600 full-term and 1300 preterm children born in the US in the year 2001. All children who entered Kindergarten and who participated in data collection at 9 months, 24 months, and Kindergarten entry were included in the study. Measures of parenting behavior were collected at 9 and 24 months and cognitive development at 24 months via home visits. Social-emotional outcomes were assessed at Kindergarten entry via parent and teacher report. Multiple-sample Structural Equation Modeling was used to analyze group differences in a model whereby early childhood parenting behavior predicted cognitive outcomes, and social-emotional outcomes at Kindergarten entry, and indirectly predicted social-emotional outcomes via early cognitive processes.

RESULTS

The full sample developmental model indicated excellent fit to the data. Preterm birth status indirectly influenced social-emotional outcomes at Kindergarten entry via its effect on early childhood parenting behavior and cognitive development. The multi-sample model revealed significant differences in the way in which early parenting behavior exerted its influence on outcomes at Kindergarten entry in preterm children compared to full-term children.

CONCLUSIONS

For preterm children, parenting indirectly influenced social-emotional outcomes via early cognitive functioning. Findings highlight the importance of early identification and targeted parenting programs to support early cognitive development in preterm children.

Cerebral palsy among children born moderately and late preterm

OBJECTIVE

To compare the incidence of and risk factors for cerebral palsy (CP) in moderately preterm (MP) (32(+0)-33(+6) weeks) and late preterm (LP) (34(+0)-36(+6) weeks) infants with those in very preterm (VP) (<32(+0) weeks) and term infants (≥37 weeks).

METHODS

The national register study included all live-born infants in Finland from 1991 to 2008. Infants who died before the age of 1 year, had any major congenital anomaly, or had missing data were excluded. A total of 1 018 302 infants were included in the analysis and they were analyzed in 4 subgroups (VP, MP, LP, and term) and 3 time periods (1991-1995, 1996-2001, and 2002-2008).

RESULTS

By the age of 7 years, 2242 children with CP were diagnosed (0.2%). CP incidence was 8.7% in the VP, 2.4% in the MP, 0.6% in the LP, and 0.1% in the term group. The risk of CP was highest in the study period 1991-1995 in all groups. Factors predictive of an increased CP risk in the MP and LP groups included resuscitation at birth (odds ratio 1.60; 95% CI 1.01-2.53 and 1.78; 1.09-2.90), antibiotic treatment during the first hospitalization (1.63; 1.08-2.45 and 1.67; 1.13-2.44), 1-minute Apgar score <7 (1.70; 1.15-2.52 and 1.80; 1.21-2.67) and intracranial hemorrhage (7.18; 3.60-14.3 and 12.8; 5.58-29.2).

CONCLUSIONS

The incidence of CP is higher in LP and MP infants compared with term infants. There is a nonlinear decrease in incidence over time and with increasing gestational age.

Development and validation of a parent-report measure for detection of cognitive delay in infancy

AIM

To develop a brief, parent-completed instrument (ERIC - Early Report by Infant Caregivers) for detection of cognitive delay in 10- to 24-month-olds born preterm, or of low birthweight, or with perinatal complications, and to establish ERIC's diagnostic properties.

METHOD

Scores for ERIC were collected from the parents of 317 children meeting ≥inclusion criterion (birthweight <1500 g, gestational age <34 completed weeks, 5 min Apgar score <7, or presence of hypoxic-ischaemic encephalopathy) and no exclusion criteria. Children were assessed using a criterion score of below 80 on the Bayley Scales of Infant and Toddler Development-III cognitive scale. Items were retained according to their individual associations with delay. Sensitivity, specificity, and positive and negative predictive values were estimated and a truncated ERIC was developed for use in children <14 months old.

RESULTS

ERIC correctly detected developmental delay in 17 out of 18 children in the sample, with 94.4% sensitivity, 76.9% specificity, 19.8% positive predictive value, 99.6% negative predictive value, 4.09 likelihood ratio positive, and 0.07 likelihood ratio negative.

INTERPRETATION

ERIC has potential value as a quickly administered diagnostic instrument for the absence of early cognitive delay in 10- to 24-month-old preterm infants and as a screen for cognitive delay.

Longer gestation among children born full term influences cognitive and motor development

Children born preterm show persisting impairments in cognitive functioning, school achievement, and brain development. Most research has focused on implications of birth prior to 37 gestational weeks; however, the fetal central nervous system continues to make fundamental changes throughout gestation. Longer gestation is associated with reduced morbidity and mortality even among infants born during the period clinically defined as full term (37-41 gestational weeks). The implications of shortened gestation among term infants for neurodevelopment are poorly understood. The present study prospectively evaluates 232 mothers and their full term infants (50.4% male infants) at three time points across the first postnatal year. We evaluate the association between gestational length and cognitive and motor development. Infants included in the study were full term (born between 37 and 41 weeks gestation). The present study uses the combination of Last Menstrual Period (LMP) and early ultrasound for accurate gestational dating. Hierarchical Linear Regression analyses revealed that longer gestational length is associated with higher scores on the Bayley scales of mental and motor development at 3, 6 and 12 months of age after considering socio-demographic, pregnancy, and infant-level covariates. Findings were identical using revised categories of early, term, and late term proposed by the Working Group for Defining Term Pregnancy. Our findings indicate that longer gestation, even among term infants, benefits both cognitive and motor development.

Late-preterm birth and neonatal morbidities: population-level and within-family estimates

PURPOSE

The objective of this study was to compare two salient neonatal outcomes-respiratory disorders and hyperbilirubinemia-between late-preterm (34-36 weeks) and full-term (37-41 weeks) singleton infants both at the population level and within families.

METHODS

Analyses were based on natality data on all births in the state of New Jersey from 1996 to 2006 linked to newborn hospital discharge records. For population-level models, logistic regression analyses were conducted to estimate unadjusted and adjusted differences in outcomes by gestational age. For within-family analyses, unadjusted and adjusted logistic fixed-effects models were estimated with the latter including factors that differed across births to the same mother.

RESULTS

Late-preterm birth increased the odds of a neonatal respiratory condition by more than fourfold (odds ratio, 4.08-4.53) and of neonatal hyperbilirubinemia by more than fivefold (odds ratio, 5.11-5.93) even when comparing births to the same mother and controlling for demographic and economic, behavioral, and obstetric factors that may have changed across pregnancies.

CONCLUSIONS

Based on population-level and within-family models, this study provides the strongest evidence to date that late-preterm birth is an important risk factor for adverse neonatal outcomes that other studies have found are associated with cognitive and behavioral disorders in childhood.

The effects of 'does not apply' on measurement of temperament with the Infant Behavior Questionnaire-Revised: A cautionary tale for very young infants

BACKGROUND

The Infant Behavior Questionnaire-Revised (IBQ-R) is a widely used parent report measure of infant temperament. Items marked 'does not apply' (NA) are treated as missing data when calculating scale scores, but the effect of this practice on assessment of infant temperament has not been reported.

AIMS

To determine the effect of NA responses on assessment of infant temperament and to evaluate the remedy offered by several missing data strategies.

STUDY DESIGN

A prospective, community-based longitudinal cohort study.

SUBJECTS

401 infants who were born>37 weeks of gestation.

OUTCOME MEASURES

Mothers completed the short form of the IBQ-R when infants were 3-months and 6-months of age.

RESULTS

The rate of NA responses at the 3-month assessment was three times as high (22%) as the rate at six months (7%). Internal consistency was appreciably reduced and scale means were inflated in the presence of NA responses, especially at 3-months. The total number of NA items endorsed by individual parents was associated with infant age and parity. None of the missing data strategies completely eliminated problems related to NA responses but the Expectation Maximization algorithm greatly reduced these problems.

CONCLUSIONS

The findings suggest that researchers should exercise caution when interpreting results obtained from infants at 3 months of age. Careful selection of scales, selecting a full length version of the IBQ-R, and use of a modern missing data technique may help to maintain the quality of data obtained from very young infants.

Mild prematurity, proximal social processes, and development

OBJECTIVE

To elucidate the role of gestational age in determining the risk of poor developmental outcomes among children born late preterm (34-36 weeks) and early term (37-38 weeks) versus full term (39-41 weeks) by examining the contribution of gestational age to these outcomes in the context of proximal social processes.

METHODS

This was an analysis of the Canadian National Longitudinal Survey of Children and Youth. Developmental outcomes were examined at 2 to 3 (N= 15099) and 4 to 5 years (N= 12302). The sample included singletons, delivered at 34 to 41 weeks, whose respondents were their biological mothers. Multivariable modified Poisson regression was used to directly estimate adjusted relative risks (aRRs). We assessed the role of parenting by using moderation analyses.

RESULTS

In unadjusted analyses, children born late preterm appeared to have greater risk for developmental delay (relative risk = 1.26; 95% confidence interval [CI], 1.01 to 1.56) versus full term. In adjusted analyses, results were nonsignificant at 2 to 3 years (late preterm aRR = 1.13; 95% CI, 0.90 to 1.42; early term aRR = 1.11; 95% CI, 0.96 to 1.27) and 4 to 5 years (late preterm aRR = 1.06; 95% CI, 0.79 to 1.43; early term aRR = 1.03; 95% CI, 0.85 to 1.25). Parenting did not modify the effect of gestational age but was a strong predictor of poor developmental outcomes.

CONCLUSIONS

Our findings show that, closer to full term, social factors (not gestational age) may be the most important influences on development.

Behavioural outcomes at 3 years of age among late preterm infants admitted to neonatal intensive care: a cohort study

OBJECTIVE

Examine the behavioural outcomes at age 3 years of late preterm infants (LPIs) who were admitted to neonatal intensive care (NIC) in comparison with LPIs who were not admitted.

METHOD

This cohort study prospectively recruited 225 children born late preterm (34-36(+6) weeks gestation) in 2006 in Northern Ireland, now aged 3 years. Two groups were compared: LPIs who received NIC (study; n=103) and LPIs who did not receive NIC (control; n=122). Parents/guardians completed the Child Behaviour Checklist/1½-5. Descriptive maternal and infant data were also collected.

RESULTS

As expected LPI children admitted to NIC had higher medical risk than the non-admitted comparison group (increased caesarean section, born at earlier gestation, lower birth weight and an episode of resuscitation at birth). LPIs admitted to NIC scored higher on the Child Behaviour Checklist/1½-5 compared with those who were not admitted indicating more behavioural problems; this was statistically significant for the Aggressive Behaviour Subscale (z=-2.36) and the Externalising Problems Scale (z=-2.42). The group difference on the Externalising Problems Scale was no longer significant after controlling for gender, gestational age and deprivation score.

CONCLUSIONS

This study provides valuable data on the behaviour at age 3 years of LPIs admitted to NIC compared with LPIs not admitted to NIC. Further research would be beneficial to explore medical and psychosocial explanations for observed differences between groups using large prospective cohort studies.

Preterm birth and its long-term effects: methylation to mechanisms

The epigenetic patterns established during development may influence gene expression over a lifetime and increase susceptibility to chronic disease. Being born preterm (<37 weeks of gestation) is associated with increased risk mortality and morbidity from birth until adulthood. This brief review explores the potential role of DNA methylation in preterm birth (PTB) and its possible long-term consequences and provides an overview of the physiological processes central to PTB and recent DNA methylation studies of PTB.

Cognitive abilities in preterm and term-born adolescents

OBJECTIVE

To investigate the influence of a range of prenatal and postnatal factors on cognitive development in preterm and term-born adolescents.

STUDY DESIGN

Woodcock-Johnson III Tests of Cognitive Abilities were used to assess general intellectual ability and 6 broad cognitive abilities in 145 young adolescents aged approximately 12.5 years and born 25-41 weeks gestational age (GA). To study potential links between neurophysiologic and cognitive outcomes, corticomotor excitability was measured using transcranial magnetic stimulation and surface electromyography. The influence of various prenatal and postnatal factors on cognitive development was investigated using relative importance regression modeling.

RESULTS

Adolescents with greater GA tended to have better cognitive abilities (particularly general intellectual ability, working memory, and cognitive efficiency) and higher corticomotor excitability. Corticomotor excitability explained a higher proportion of the variance in cognitive outcome than GA. But the strongest predictors of cognitive outcome were combinations of prenatal and postnatal factors, particularly degree of social disadvantage at the time of birth, birthweight percentile, and height at assessment.

CONCLUSIONS

In otherwise neurologically healthy adolescents, GA accounts for little interindividual variability in cognitive abilities. The association between corticomotor excitability and cognitive performance suggests that reduced connectivity, potentially associated with brain microstructural abnormalities, may contribute to cognitive deficits in preterm children. It remains to be determined if the effects of low GA on cognitive outcomes attenuate over childhood in favor of a concomitant increase in the relative importance of heritability, or alternatively, if cognitive development is more heavily influenced by the quality of the postnatal environment.

Late prematurity: a systematic review

OBJECTIVE

this study aimed to review the literature regarding late preterm births (34 weeks to 36 weeks and 6 days of gestation) in its several aspects.

SOURCES

the MEDLINE, LILACS, and Cochrane Library databases were searched, and the references of the articles retrieved were also used, with no limit of time.

DATA SYNTHESIS

numerous studies showed a recent increase in late preterm births. In all series, late preterm comprised the majority of preterm births. Studies including millions of births showed a strong association between late preterm birth and neonatal mortality. A higher mortality in childhood and among young adults was also observed. Many studies found an association with several neonatal complications, and also with long-term disorders and sequelae: breastfeeding problems, cerebral palsy, asthma in childhood, poor school performance, schizophrenia, and young adult diabetes. Some authors propose strategies to reduce late preterm birth, or to improve neonatal outcome: use of antenatal corticosteroids, changes in some of the guidelines for early delivery in high-risk pregnancies, and changes in neonatal care for this group.

CONCLUSIONS

numerous studies show greater mortality and morbidity in late preterm infants compared with term infants, in addition to long-term disorders. More recent studies evaluated strategies to improve the outcomes of these neonates. Further studies on these strategies are needed.

Neonatal morbidity occurs despite pulmonary maturity prior to 39 weeks gestation

OBJECTIVE

To compare outcomes among late-preterm or early-term neonates according to fetal lung maturity (FLM) status.

STUDY DESIGN

We conducted a retrospective cohort study of 234 eligible singletons delivered after FLM testing before 39 weeks gestation at our center over a 2-year time period. A primary composite neonatal outcome included death and major morbidities.

RESULT

The overall rate of primary composite morbidity was 25/46 (52.2%) and 61/188 (32.4%) in the immature/transitional and mature groups, respectively. After adjustment for confounders including gestational age, the composite outcome was not significantly different; adjusted odds ratio (aOR)=1.4 (confidence interval (CI)=0.7-3.0). The rate of respiratory distress syndrome was significantly higher in the immature/transitional group; odds ratio=3.4 (CI=1.1-10.3) as expected.

CONCLUSION

FLM status did not correlate with the spectrum of neonatal morbidities in late-preterm and early-term births. Neonatal complications remained common in both groups.

Difficulty in Mental, Neuromusculoskeletal, and Movement-Related School Functions Associated With Low Birthweight or Preterm Birth: A Meta-Analysis

OBJECTIVE. Our objective was to perform a meta-analysis to investigate whether low birthweight (LBW) or preterm birth was associated with difficulty in mental, neuromusculoskeletal, and movement-related school function tasks.

METHOD. Two search strategies produced 40 studies that met the inclusion criteria for the meta-analysis and yielded 549 effect sizes (d). Heterogeneity was evaluated by obtaining Q and I-squared values. Egger’s regression intercept test and a funnel plot were used to check for publication bias.

RESULTS. Children born LBW exhibited considerable difficulties in mental (d = −0.655, p &lt; .0001) and neuromusculoskeletal and movement-related tasks (d = −0.391, p &lt; .0001) compared with children of normal birthweight. Children born preterm also exhibited significant difficulties compared with full-term children in mental, neuromusculoskeletal, and movement-related tasks (d = −0.237, p &lt; .0001).

CONCLUSION. Deficits in mental and motor functions in children born LBW or preterm appear to have significant effects on school readiness and academic achievement.

Vitamin D status among preterm and full-term infants at birth

BACKGROUND

Risk factors for maternal vitamin D deficiency and preterm birth overlap, but the distribution of 25-hydroxyvitamin D (25(OH)D) levels among preterm infants is not known. We aimed to determine the associations between 25(OH)D levels and gestational age.

METHODS

We measured umbilical cord plasma levels of 25(OH)D from 471 infants born at Brigham and Women's Hospital in Boston. We used generalized estimating equations to determine whether preterm (<37 wks' gestation) or very preterm (<32 wks' gestation) infants had greater odds of having 25(OH)D levels below 20 ng/ml than more mature infants. We adjusted for potential confounding by season of birth, maternal age, race, marital status, and singleton or multiple gestation.

RESULTS

Mean cord plasma 25(OH)D level was 34.0 ng/ml (range: 4.1-95.3 and SD: 14.1). Infants born before 32 wks' gestation had increased odds of having 25(OH)D levels below 20 ng/ml in unadjusted (odds ratio (OR): 2.2; 95% confidence interval (CI): 1.1-4.3) and adjusted models (OR: 2.4; 95% CI: 1.2-5.3) as compared with more mature infants.

CONCLUSION

Infants born in <32 wks' gestation are at higher risk than more mature infants for low 25(OH)D levels. Further investigation of the relationships between low 25(OH)D levels and preterm birth and its sequelae is thus warranted.

Serial diffusion tensor images during infancy and their relationship to neuromotor outcomes in preterm infants

BACKGROUND

Even preterm infants with normal magnetic resonance imaging (MRI) results are at greater risk for neuromotor dysfunction.

OBJECTIVES

Our aim was to compare serial diffusion tensor imaging (DTI) data from preterm infants without apparent brain abnormalities on magnetic resonance imaging with those from term controls and to investigate the white matter (WM) region associated with neuromotor outcomes.

METHODS

We obtained serial DTIs from 21 preterm infants at term-equivalent age (TEA) and 1 year of corrected age. As controls, 15 term neonates and 20 newly recruited term infants aged 1 year underwent DTI. Preterm and term infants at 1 year of age were assessed with the Bayley Scales of Infant Development, second edition. Tract-based spatial statistics and regions of interest were used for analysis.

RESULTS

At TEA, the entire WM development was delayed in the preterm infants compared with the term controls, but at 1 year of age, the WM development, except for that of the corpus callosum (CC), had reached the development level of the term controls. The psychomotor developmental index was positively correlated with the fractional anisotropy (FA) in the CC (particularly in the body and splenium) at 1 year of age after correcting for gestational age, chronic lung disease, and postnatal infection.

CONCLUSIONS

The CC of the preterm infants was consistently underdeveloped compared with that of the term controls. The FA in the CC, particularly in the body and splenium at 1 year of age, well reflected the degree of motor function in infants without apparent brain abnormalities.

Long-term outcomes of moderately preterm, late preterm, and early term infants

At present, moderate preterm (MPT) infants born at 32 to 33 weeks' gestation and late preterm (LPT) infants born at 34 to 36 weeks' gestation make up the largest subgroup of preterm infants and contribute to more than 80% of premature births in the United States. There is increasing evidence that both MPT and LPT infants are at increased risk of neurologic impairments, developmental disabilities, school failure, and behavior and psychiatric problems. Population studies suggest that for each 1 week decrease in gestational age below 39 weeks, there are stepwise increases in adverse outcomes after adjusting for confounders.

Epidemiology of moderate preterm, late preterm and early term delivery

Moderate preterm, late preterm, and early term deliveries represent a major and growing public health concern. These deliveries are associated with significant financial burden and pose serious risks to mothers and newborns. Women who deliver at moderate and late gestational ages in one pregnancy are at increased risk of delivering at these gestational ages, or earlier, in a subsequent pregnancy. Births in moderate preterm and late preterm gestational ages are associated with significant infant morbidity and mortality. Efforts to reduce deliveries in moderate preterm and late preterm gestations and interventions designed to ameliorate the problems in infants delivered at the gestational ages may be targets worthy of future investigation.

Born too soon: the global epidemiology of 15 million preterm births

This second paper in the Born Too Soon supplement presents a review of the epidemiology of preterm birth, and its burden globally, including priorities for action to improve the data. Worldwide an estimated 11.1% of all livebirths in 2010 were born preterm (14.9 million babies born before 37 weeks of gestation), with preterm birth rates increasing in most countries with reliable trend data. Direct complications of preterm birth account for one million deaths each year, and preterm birth is a risk factor in over 50% of all neonatal deaths. In addition, preterm birth can result in a range of long-term complications in survivors, with the frequency and severity of adverse outcomes rising with decreasing gestational age and decreasing quality of care. The economic costs of preterm birth are large in terms of immediate neonatal intensive care, ongoing long-term complex health needs, as well as lost economic productivity. Preterm birth is a syndrome with a variety of causes and underlying factors usually divided into spontaneous and provider-initiated preterm births. Consistent recording of all pregnancy outcomes, including stillbirths, and standard application of preterm definitions is important in all settings to advance both the understanding and the monitoring of trends. Context specific innovative solutions to prevent preterm birth and hence reduce preterm birth rates all around the world are urgently needed. Strengthened data systems are required to adequately track trends in preterm birth rates and program effectiveness. These efforts must be coupled with action now to implement improved antenatal, obstetric and newborn care to increase survival and reduce disability amongst those born too soon.

Developmental delay in moderately preterm-born children with low socioeconomic status: risks multiply

OBJECTIVE

To assess separate and joint effects of low socioeconomic status (SES) and moderate prematurity on preschool developmental delay.

STUDY DESIGN

Prospective cohort study with a community-based sample of preterm- and term-born children (Longitudinal Preterm Outcome Project). We assessed SES on the basis of education, occupation, and family income. The Ages and Stages Questionnaire was used to assess developmental delay at age 4 years. We determined scores for overall development, and domains fine motor, gross motor, communication, problem-solving, and personal-social of 926 moderately preterm-born (MP) (32-36 weeks gestation) and 544 term-born children. In multivariable logistic regression analyses, we used standardized values for SES and gestational age (GA).

RESULTS

Prevalence rates for overall developmental delay were 12.5%, 7.8%, and 5.6% in MP children with low, intermediate, and high SES, respectively, and 7.2%, 4.0%, and 2.8% in term-born children, respectively. The risk for overall developmental delay increased more with decreasing SES than with decreasing GA, but the difference was not statistically significant: OR (95% CI) for a 1 standard deviation decrease were: 1.62 (1.30-2.03) and 1.34 (1.05-1.69), respectively, after adjustment for sex, number of siblings, and maternal age. No interaction was found except for communication, showing that effects of SES and GA are mostly multiplicative.

CONCLUSIONS

Low SES and moderate prematurity are separate risk factors with multiplicative effects on developmental delay. The double jeopardy of MP children with low SES needs special attention in pediatric care.

Circulatory insulin-like growth factor-I and brain volumes in relation to neurodevelopmental outcome in very preterm infants

BACKGROUND

To evaluate the relationships between postnatal change in circulatory insulin-like growth factor-I (IGF-I) concentrations, brain volumes, and developmental outcome at 2 y of age in very preterm infants.

METHODS

IGF-I was measured weekly, and nutritional intake was calculated daily from birth until a postmenstrual age (PMA) of 35 wk. Individual β coefficients for IGF-I, IGF-I(B), representing the rate of increase in IGF-I from birth until a PMA of 35 wk were calculated. Brain magnetic resonance imaging was performed at term age, with segmentation into total brain, cerebellar, gray matter, and unmyelinated white matter volume (UWMV). Developmental outcome was evaluated using Bayley Scales of Infant Development-II.

RESULTS

Forty-nine infants, with mean gestational age (GA) of 26.0 wk, were evaluated at mean 24.6 mo corrected age. Higher IGF-I(B), UWMV, and cerebellar volume were associated with a decreased risk for a Mental Developmental Index (MDI) < 85 (odds ratio (95% confidence interval): 0.6 (0.4-0.9), 0.96 (0.94-0.99), and 0.78 (0.6-0.96), respectively). In multivariate analysis, higher IGF-I(B) and higher UWMV combined with female gender constituted the two models with the highest predictive value for MDI > 85.

CONCLUSION

A higher rate of increase in circulating IGF-I is associated with a decreased risk for subnormal MDI at 2 y of corrected age. This relationship is in part dependent on brain volume at term age.

Late-preterm birth and lifetime socioeconomic attainments: the Helsinki birth cohort study

OBJECTIVE

We examined if those born late-preterm (at 34 to 36 weeks of gestation) differed from those born at term in their maximum attained lifetime socioeconomic position (SEP) across the adult years up to 56 to 66 years, and in intergenerational social mobility from childhood parental SEP to own attained SEP.

METHODS

Participants were 8993 Finnish men and women of the Helsinki Birth Cohort Study born between 1934 and 1944. Gestational age was extracted from hospital birth records and socioeconomic attainments from Finnish National Census.

RESULTS

Compared with those born at term, those born late-preterm were more likely to be manual workers, have a basic or upper secondary level of education, belong to the lowest third based on their incomes, and less likely to belong to the highest third based on their incomes. Late-preterm individuals were also less likely to be upwardly mobile and more likely to be downwardly mobile; they were less likely to have higher occupations and more likely to have lower occupations than their fathers. They were also less likely to be upwardly mobile if incomes were used as the outcome of own attained SEP, and men were more likely to be downwardly mobile if education was used as the outcome of own attained SEP.

CONCLUSIONS

This study demonstrates that there are considerable long-term socioeconomic disadvantages associated with late-preterm birth, which are not explained by the parent-of-origin SEP.