The influence of extrauterine life on the aEEG maturation in normal preterm infants

Objective

To study, the maturational changes of the amplitude-integrated electroencephalogram (aEEG) in preterm infants without neurological disorders and especially the influence of the duration of extrauterine life, over this process.

Methods

96 preterm infants, 25-34 weeks' gestational age (GA) at birth, clinically stable and without ultrasonographic evidence of neurological abnormalities, were studied. The aEEG recordings were obtained within 72 h of life and then weekly until discharge. Four aspects of each tracing (continuity, sleep-wake cycling, bandwidth, and lower border), were evaluated by visual analysis, applying pre-established criteria.

Results

We analysed 624 aEEG recordings at postmenstrual age (PMA) of 25-42 weeks. With advanced GA the aEEG becomes more continuous (p: 0.022), it displays definite sleep-wake cycles (p: 0.011), and its bandwidth acquires the mature pattern (p: 0.012). A positive significant interaction of GA and PMA in the evolution of aEEG was found regarding continuity (p: 0.002), sleep-wake cycling (p: 0.002), and bandwidth (p: 0.02).

Conclusion

The evolution of the aEEG tracing depends on both GA and PMA. The older the infants at birth the more mature the aEEG pattern. At the same PMA, preterm infants of lower GA display an advanced maturation of the aEEG comparing with others of higher GA.     

Circulating adipocyte fatty acid binding protein levels in healthy preterm infants: Positive correlation with weight gain and total-cholesterol levels

Background

Adipocyte fatty acid binding protein (a-FABP) has been suggested to play an important role in the pathogenesis of metabolic syndrome. Preterm infants are at risk for the later development of insulin resistance, and, possibly, other components of metabolic syndrome.

Aim

To determine circulating levels of a-FABP in preterm infants and examine possible associations of a-FABP with metabolic indices (serum lipids, glucose, and insulin levels, and homeostasis model assessment index of insulin resistance [HOMA-IR]), levels of leptin and adiponectin, anthropometric parameters and weight gain.

Study design

Prospective cohort study.

Subjects

55 healthy preterm (mean [SD] gestational age 32.8 [1.8] weeks) and 23 fullterm infants (reference group).

Outcome measures

Serum a-FABP, lipids, glucose, insulin, leptin and adiponectin levels at 31.9 [10.4] days of life.

Results

Serum a-FABP levels did not differ significantly between preterm and fullterm infants. A-FABP levels correlated positively with total-cholesterol [total-C] in both preterm and fullterm infants (β = 0.33; p = 0.01 and β = 0.33; p = 0.04, respectively). In addition to total-C, weight gain correlated independently with a-FABP levels in preterm infants (β = 0.36, p = 0.01).

Conclusions

An association between a-FABP levels and indices of insulin resistance was not present in infants studied. As the development of insulin resistance in children born prematurely is possibly associated with weight gain in early postnatal life, follow-up of our study population is necessary to demonstrate whether a-FABP levels, shown to correlate with weight gain in preterm infants, are a predictive marker for the later development of insulin resistance in these infants.     

Functional impairments at school age of preterm born children with late-onset sepsis

Background

Late-onset sepsis is a relatively common complication particularly of preterm birth that affects approximately a quarter of very low birth weight infants.

Aim

We aimed to determine the motor, cognitive, and behavioural outcome at school age of preterm children with late-onset sepsis compared to matched controls.

Study design and subjects

A prospective case-control study that included preterm infants (gestational age < 32 weeks and/or birth weight < 1500 g) admitted to our Neonatal Intensive Care Unit in 2000-2001 with a culture-proven late-onset sepsis, and controls matched for gestational age.

Outcome measures

At school age we assessed motor skills, intelligence, visual perception, visuomotor integration, verbal memory, attention, executive functioning, and behaviour.

Results

At 6-9 years, 21 of 32 children with late-onset sepsis (68%) had borderline or abnormal motor outcome with most problems in fine motor skills. Their total IQ was 89 compared to 98 in controls. In addition, verbal memory and attention were affected compared to controls (0.61 standard deviations (SD), 95% confidence interval (CI) 0.04-1.17, p = 0.033 and 0.94 SD, 95% CI 0.32-1.62, p = 0.011, respectively). Multiple episodes of sepsis and gram-negative sepsis were risk factors for worse cognitive outcome.

Conclusions

At school age, a majority of preterm children with late-onset sepsis had motor problems. Their IQ was considerably lower than matched controls, and memory and attention were specifically impaired. Outcome at school age of preterm children with late-onset sepsis was worse than previously thought.     

Quantitative electroencephalographic patterns in normal preterm infants over the first week after birth

Background

Currently available tools to assist clinicians with prediction of neurodevelopmental outcome of preterm infants are inadequate. Modified cotside electroencephalography (EEG) has the ability to produce quantitative electrophysiologic measures. These measures may be useful in future prediction of outcome.

Aim

To determine patterns of change in quantitative EEG measures in preterm infants during their first week after birth.

Design

Observational.

Subjects

Preterm infants born at less than 32 weeks completed gestation surviving to discharge with unremarkable serial ultrasound scans.

Outcome measures

Changes in continuity, amplitude and spectral edge frequency measures of EEGs obtained over the first week after birth.

Results

Results of EEGs performed using a novel EEG device on 63 infants are reported here. Their median (range) gestation was 29 (24-31) weeks and birthweight was 1235 (540-1980) g. Quantitative measures of EEG continuity increased over the first week after birth from 72 (25-99)% to 92 (54-100)% at the 25 μV threshold, and from 39 (10-87)% to 64 (34-75)% at the 50 μV threshold, both p < 0.0001. There was a related 32% increase in median amplitude from 5.8 (2.6-10.6) μV on day 1 to 7.6 (4.3-9.4) μV on day 4, p = 0.005. There was a trend for average spectral edge frequency to fall from 10.7 (9.3-12.9) Hz on day 1 to 9.9 (8.1-12.3) Hz on day 3, p = 0.06. Each gestational tertile showed similar patterns.

Conclusions

There are consistent changes in quantitative neurophysiologic measures over the first week after birth, and particularly measures of continuity over the first 4 days, in normal preterm infants.     

Skin conductance measurements as pain assessment in newborn infants born at 22-27 weeks gestational age at different postnatal age

Background

To assess pain or stress in newborn infants submitted to intensive care is important but difficult, as different observational pain scales are not always reliable in premature infants. As an indicator of pain, skin conductance (SC) measurements have detected increased sweating in newborn infants > 28 gestational age (GA) submitted to heel lancing.

Objective

To measure SC during heel lancing and routine care in newborn infants, born at 22 to 27 GA, with special relation to postnatal age (PNA).

Methods

In six infants < 28 + 0 GA and 4 infants ≥ 28 + 0 GA spontaneous SC activity and behavioural state (Neonatal Pain Agitation and Sedation Scale (N-PASS)) was measured before, during and after each intervention. Measurements were repeated in each patient at different PNA.

Results

Baseline SC prior to intervention took longer time to stabilise and was higher in < 28 than in ≥ 28 + 0 PNA. The combination of heel lancing and squeezing gave an increased SC in < 28 PNA, whereas heel lancing alone gave the same SC response in ≥ 28 + 0 PNA. A possibly continued immature response in SC measurements was not observed. Oral glucose admission prior to heel lancing increased SC. Routine care did not give any changes in SC. Except during orogastric tube placement no signs of discomfort or pain could be detected by the neonatal pain, agitation and sedation scale (N-PASS) in < 28 PNA.

Conclusion

Changes in SC could be detected in infants at < 28 + 0 PNA and related to the combination of heel lancing and squeezing. A maturational development of the SC was observed in infants born < 28 GA. SC seems to be able to differentiate between pain and discomfort.     

Is term newborn body composition being achieved postnatally in preterm infants?

Background

The American Academy of Pediatrics (AAP) recommends that preterm infants' growth duplicates fetal growth rates and that body composition replicates in utero body composition.

Aims

To compare the total body fat mass between preterm infants assessed at term corrected age and full-term newborns, and to investigate the effects of gestational age, gender, weight increase, being breast fed on total adiposity.

Study design

Prospective observational study.

Subjects

One hundred and ten preterm infants [mean (SD) gestational age: 29.9 (2.3) weeks; birth weight: 1118 (274) g], and 87 full term [mean (SD) 38.6 (1.21) weeks, 3203 (385) g], breastfed infants.

Outcome measures

Growth and body composition by means of a pediatric air displacement system were assessed at term corrected age in preterm infants and on day 3 of life in full term infants.

Results

Weight, length and head circumference were smaller in the preterm group as compared to the term group. Mean (SD) percentage of fat mass in preterm infants was significantly higher as compared to term infants [14.8 (4.4) vs 8.59 (3.71), P < 0.0001]. Fat mass was negatively correlated with gestational age (P < 0.001), and positively associated with weight increase (P < 0.05).

Conclusions

Our data suggest that body composition, in terms of fat mass, in preterm infants at term corrected age is different from that of full term newborns.     

Sex and gestational age effects on auditory brainstem responses in preterm and term infants

Background

Some studies find delayed development of the auditory brainstem in preterm infants, but others do not.

Aim

To compare auditory brainstem responses (ABRs) in healthy preterm and term infants depending on sex and gestational age (GA).

Methods

Participants were 111 preterm (27–36 weeks GA) and 92 term (37–41 weeks GA) infants. ABR tests were conducted at 6 weeks (corrected age if preterm).

Results

There were no overall differences between term and preterm groups in ABRs. However, males showed longer latencies for waves III, V, and I–III, III–V, and I–V intervals and smaller amplitudes for wave III and V than females in both preterm and term groups (all p values ≤ .01). A 3-way interaction between group, sex, and GA (p < .05) showed that preterm males with later GA had longer wave I–V interval, whereas term females with later GA showed shorter wave I-V interval. Growth velocity predicted wave I–V interval in preterm infants, controlling for other factors (male: p = .07, female: p < .05).

Conclusion

ABRs in preterm and term infants were similar at 6 weeks (corrected age if preterm), but males had less advanced ABRs than females. More rapid growth predicted less mature ABR in later GA preterm infants in this setting where they were unlikely to receive extra iron. The roles of GA, growth, and iron balance in ABR development warrant further study.     

Recurrent otitis media with effusion in preterm infants with histologic chorioamnionitis--a 3 years follow-up study

Background

Recurrent otitis media with effusion (OME) is a leading cause of acquired hearing loss in childhood. Histological chorioamnionitis (HCA) is an important cause of preterm delivery and neonatal morbidity and mortality. Here, we tested the hypothesis of an association between recurrent OME during the first 3 years of life and HCA in very low birth weight (VLBW) infants.

Methods

A total of 110 randomly selected VLBW preterm newborns with HCA and 135 gestational age and gender-matched, HCA-negative VLBW infants were evaluated prospectively during the first 3 years of life for the presence of OME, as diagnosed on the basis of otoscopy, type B or C tympanogram, ipsilateral absence of transient evoked otoacoustic emissions responses, and ipsilaterally increased threshold at diagnostic auditory brain responses evaluation. Potential risk factors for OME were also examined in the two groups.

Results

The HCA-positive infants showed a ~ six times higher frequency of recurrent OME (P < 0.0001), increased frequency (> 5/yr) of clinical otitis media episodes (P = 0.000020), ~ five times higher frequency of adenoid hypertrophy (P < 0.00001), a significant seasonal pattern of birth with autumn predominance (P < 0.00001), and the first OME occurred earlier (P < 0.0001), as compared to the HCA-negative counterparts. Recurrent OME was significantly associated with HCA (O.R. = 17.76, 95% CI: 8.98-35.13, P < 0.00001), adenoid hypertrophy (O.R. = 9.96, 95% CI: 5.17-19.18, P < 0.00001), frequency of acute otitis episodes > 5/yr (O.R. = 8.91, 95% CI: 1.96-40.41, P = 0.0005), and birth in autumn (O.R. = 5.58, 95% CI: 2.79-11.12, P < 0.00001).

Conclusions

These findings indicate that HCA is a previously unrecognized risk factor for the development of recurrent bilateral OME in VLBW preterm infants during the first 3 years of life.     

Early assessment of visual function in preterm infants: How early is early?

Background

Several studies reported on various aspects of visual function at term age and in the first months after birth but less has been reported in preterm infants before they reach termequivalent age.

Aims

To assess the suitability of a battery of tests of visual function for use in infants born at < 33 weeks gestation (GA) and assessed before 34 weeks post-menstrual age (PMA); to evaluate the distribution of the findings according to GA, and to compare the data with those previously published on preterm infants assessed at 35 weeks PMA.

Study design

Cross-sectional study.

Subjects

Sixty-four preterm infants with a GA < 33 weeks were studied.

Outcome measures

We used a battery of visual function tests previously validated at 35 and 40 weeks PMA in low-risk preterm infants. All the infants in this current study underwent the same assessment before 34 weeks PMA.

Results

Before 31 weeks PMA most infants could not be reliably assessed because of clinical instability, whilst after 31 weeks PMA most infants could be assessed and they showed progressive maturation in their responses with PMA. Some items (spontaneous ocular motility, horizontal tracking, tracking a coloured stimulus, and ocular fixation) showed similar results at 32-33 weeks PMA to those found in low-risk preterm at 35 weeks PMA. Ocular movements to a target and arc tracking were the items with the most immature responses.

Conclusions

Our results provide further evidence that a structured assessment of visual function can be used in clinical routine and for research purposes in infants as young as 31 weeks PMA.     

Prediction of developmental performance in preterm infants at two years of corrected age: contribution of the neurological assessment at term age

Background

The population of preterm infants is increasing and resources available for follow-up are limited. Early markers are needed to identify children who will show major as well as more subtle neurodevelopmental impairments. Such a challenge could be achieved with the Amiel-Tison Neurological Assessment at Term (ATNAT).

Aims

This study assesses the usefulness of the ATNAT in the prediction of developmental problems at two years of corrected age (CA) in infants born between 29 and 37 weeks of gestation.

Method

Inclusion criteria were: gestational age between 29^0/7 and 36^6/7 weeks inclusively, birth weight below 2500 g and minimal 24-hour stay in the Neonatal Intensive Care Unit of Sainte-Justine Hospital. A sample of 147 was prospectively recruited and assessed at two ages: at term with the ATNAT and at 24 months CA with Bayley Scales of Infant Development-II.

Results

No major impairment such as cerebral palsy and no neurosensory impairment were observed. Developmental delay defined by an index < 70 on the mental or psychomotor scale was reported respectively in 6.2% and 5.4% of the cohort. Significant differences in mental, psychomotor and behavioral performances were found according to neurological status. Neurological status was the only variable to enter the predictive model for psychomotor and behavioral indexes. Gender and neurological status remained in the predictive model for mental performance.

Conclusion

This study supports the inclusion of the ATNAT among the eligibility criteria for systematic neurodevelopmental surveillance as it allows early identification of infants at higher risk of low developmental performances at 24 months CA.     

Reduced cerebellar diameter in very preterm infants with abnormal general movements

Background

Abnormal General Movements (GMs) early in life are predictive of later neuromotor deficits and are related to white matter abnormalities on magnetic resonance imaging (MRI). However, other structural correlates of abnormal GMs have not been defined.

Aims

The objective of this study was to explore brain-metrics (linear brain measurements on MRI representative of 3-D brain volumes) at term as a predictor of abnormal GMs at 1 and 3 months' corrected age in preterm infants. It was hypothesized that abnormal GMs would be related to reduced brain-metrics in primary motor areas, namely the cerebellum and parietal lobes.

Study design

Eighty three preterm infants (< 30 weeks' gestational age) were scanned at term-equivalent age. MRI was assessed for white matter abnormality and brain-metrics in six predefined brain regions (i.e. bifrontal, biparietal, lateral ventricles and transverse cerebellar diameters, and inter-hemispheric distance).

Outcome measures

At 1 and 3 months' corrected age infants' GMs were assessed from video-taped footage and rated as normal or abnormal using standardized methodology.

Results

At 1 month, 63% (n = 52) of infants had abnormal GMs with no association between any of the brain-metrics and abnormal GMs. At 3 months, 23% (n = 18) of infants had abnormal GMs (absent fidgety movements n = 18; abnormal fidgety movements n = 0). Reduced bifrontal, biparietal, and cerebellar transverse diameters, along with an increase in lateral ventricle sizes were associated with an increased risk of abnormal GMs at 3 months' corrected age. After controlling for white matter abnormality and grade III/IV intraventricular haemorrhage, only the cerebellar transverse diameter was predictive of abnormal GMs at 3 months.

Conclusions

Reduced cerebellar diameter at term equivalent age is related to abnormal GMs at 3 months' corrected age, independent of white matter abnormality and intraventricular haemorrhage.     

Placental pathology is associated with illness severity in preterm infants in the first twenty-four hours after birth

Background

Placental pathology is associated with long-term neurological morbidity. Little is known about the association of placental pathology and illness severity directly after birth in preterm infants.

Objective

To determine the association between placental pathology and illness severity in preterm infants during the first 24 h after birth.

Study design

Placentas of 40 preterm infants, born after singleton pregnancies (gestational age 25.4-31.7 weeks, birth weight 560-2250 g) were assessed for histopathology. Illness severity was measured using the Score of Neonatal Acute Physiology Perinatal Extension (SNAPPE). A high SNAPPE reflects high illness severity.

Results

Examination of the 40 placentas revealed: pathology consistent with maternal vascular underperfusion (MVU) (n = 24), ascending intrauterine infection (AIUI) (n = 17), villitis of unknown aetiology (VUE) (n = 6), foetal thrombotic vasculopathy (FTV) (n = 6), elevated nucleated red blood cells (NRBCs) (n = 6), and chronic deciduitis (n = 10). SNAPPE ranged from 1 to 53 (median 10). Infants with elevated NRBCs had a higher SNAPPE than infants without elevated NRBCs (median 30 vs. 10, p = 0.014). The same was found for the presence of FTV (median 30 vs. 10, p = 0.019). No relation existed between SNAPPE and the other placental pathologies.

Conclusions

Elevated NRBCs and FTV were associated with higher illness severity during the first 24 h after birth in preterm infants. Ascending intrauterine infection was not associated with high illness severity.     

Nucleated red blood cells and early EEG: predicting Sarnat stage and two year outcome

Aims

Hypoxic Ischaemic Encephalopathy (HIE) causes characteristic changes of the electroencephalogram (EEG), and a raised Nucleated Red Blood Cell (NRBC) count compared to controls. We wished to examine whether combining these markers could improve their ability to predict HIE severity in the first 24 h.

Methods

Term infants with HIE were recruited. NRBC count and continuous multi-channel EEG were recorded within the first 24 h. Neurological assessment was carried out at 24 months. A control population with NRBC counts in the first 24 h was recruited.

Results

44 infants with HIE and 43 control infants were recruited. Of the HIE population 39 completed a 2 year follow-up. The median NRBC count differed significantly between the controls and those with HIE (3/100 WBC [range of 0-11] vs 12.3/100 WBC [0-240]) (p < 0.001). Within the HIE population the median NRBC count was significantly greater in infants with moderate/severe HIE than mild (16/100 WBC [range of 0-240] vs 8/100 WBC [1-23]) (p = 0.016), and among infants with abnormal outcome compared to normal (21.3/100 WBC [1-239.8] vs 8.3/100 WBC [0-50])(p = 0.03).The predictive ability of EEG changed with time post-delivery, therefore results are given at both 12 and 24 h of age. At both time points the combined marker had a stronger correlation than EEG alone; with HIE severity (12 h: r = 0.661 vs r = 0.622), (24 h: r = 0.645 vs r = 0.598), and with outcome at 2 years (12 h: r = 0.756 vs r = 0.652), (24 h: r = 0.802 vs r = 0.746).

Conclusion

Combining early EEG and NRBC count to predict HIE severity and neurological outcome, improved the predictive ability of either in isolation.     

Amplitude-integrated electroencephalographic activity is suppressed in preterm infants with high scores on illness severity

Background

The neonatal acute physiology score, SNAP-II, reflects the severity of illness in newborns. In term newborns, amplitude integrated EEG (aEEG), is depressed following asphyxia. In preterm infants aEEG is discontinuous, and therefore more difficult to assess compared to term infants.

Aims

Our first aim was to investigate whether assessing aEEG amplitudes by calculating amplitude centiles was consistent with assessment by pattern recognition. Our second aim was to investigate whether the aEEGs of preterm infants were influenced by SNAP-II.

Study Design and Subjects

We recorded aEEGs in 38 infants with a mean gestational age of 29.7 weeks (26.0-31.8 weeks) during the first five days of life. The mean recording time was 130 min. The aEEGs were assessed by pattern recognition, by calculating Burdjalov score, and by calculating the mean values of the 5th, 50th, and 95th centiles of the aEEG amplitudes. Illness severity was determined within the first 24 h.

Results

We assessed 151 recordings and found strong correlations between the 5th and 50th amplitude centiles and the Burdjalov scores (r = 0.71, p < 0.001 and r = 0.47, p < 0.001, respectively). The 5th and 50th amplitude centiles correlated with SNAP-II (r = − 0.34, p < 0.0001 and r = − 0.27, p = 0.001). These correlations were the strongest on the first day of life (r = − 0.55, p = 0.005 and r = − 0.47, p = 0.018, respectively). The 5th and the 50th amplitude centiles were best predicted by gestational age, SNAP-II, and low blood pressure.

Conclusions

Severe illness as measured by the SNAP-II, and low blood pressure had a negative influence on the aEEGs of preterm infants.     

Establishing a reference range for triiodothyronine levels in preterm infants

Objectives

Thyroid dysfunction affects clinical complications in preterm infants and older children. However, thyroid hormone replacement in preterm infants has no proven benefits, possibly owing to the lack of an appropriate reference range for thyroid hormone levels. We aimed to establish a reference range for triiodothyronine (T3) levels at 1-month postnatal age (PNA) in preterm infants.

Methods

This retrospective study included preterm infants born at a tertiary referral neonatal center at gestational age (GA) < 35 weeks with no apparent thyroid dysfunction, for 6 consecutive years, with follow-up from PNA 2 weeks to 16 weeks. Using thyroid function tests (TFT), the relationships between T3 levels and thyrotropin (TSH) and free thyroxine (fT4) levels, birth weight, GA, postmenstrual age (PMA), and PNA were examined. The conversion trend for fT4 to T3 was analyzed using the T3/fT4 ratio.

Results

Overall, 464 TFTs from 266 infants were analyzed, after excluding 65 infants with thyroid dysfunction. T3 levels increased with fT4 levels, birth weight, GA, PMA, and PNA but not with TSH levels. The T3/fT4 ratio also increased with GA, PNA, and PMA. The average T3 level at 1 month PNA was 72.56 ± 27.83 ng/dL, with significant stratifications by GA.

Conclusions

Relatively low T3 and fT4 levels in preterm infants were considered normal, with T3 levels and conversion trends increasing with GA, PMA, and PNA. Further studies are required to confirm the role of the present reference range in thyroid hormone replacement therapy.     

Uniform treatment thresholds for hyperbilirubinemia in preterm infants: background and synopsis of a national guideline

Background

To prevent severe hyperbilirubinemia and bilirubin neurotoxicity, the American Academy of Pediatrics' management guideline for hyperbilirubinemia in near term infants is used worldwide. A leading guideline for jaundiced preterm infants is lacking whereas the risk on severe hyperbilirubinemia is high in these infants. Our aim was to define uniform treatment thresholds for jaundiced preterm infants. In this article we present the history and a synopsis of this novel national guideline.

Study Design

A survey on guidelines for hyperbilirubinemia in preterm infants was sent to all Dutch Neonatal Intensive Care Units (NICUs). After comparison with international guidelines, a new consensus-based guideline was developed.

Results

Treatment thresholds of all 10 NICUs were based on Total Serum Bilirubin (TSB) and related to birth weight (n = 9) and gestational age (n = 1). NICUs used age-specific (n = 6) or fixed (n = 4) TSB-thresholds resulting in a large range of thresholds (maximal 170 μmol/L for phototherapy and 125 μmol/L for exchange transfusion). Acidosis, asphyxia, sepsis, active hemolysis and intraventricular hemorrhage were the most frequently used risk factors. Consensus was agreed upon TSB-based treatment thresholds, categorized in 5 birth weight groups and divided in high and low risk infants.

Conclusion

There was no standardized care for jaundiced preterm infants in the Netherlands. In addition to the internationally used guideline for (near) term infants, a novel “consensus based” guideline for preterm infants with a gestational age of less than 35 weeks has been developed and implemented in the Netherlands. This guideline is approved and recommended by the Dutch Society of Pediatrics.     

Motor trajectories from 4 to 18 months corrected age in infants born at less than 30 weeks of gestation

Background

Preterm infants are recognised as developing at a significantly slower rate than their full-term peers and with different movement quality.

Aim

This study aimed to describe the longitudinal gross motor trajectories of these infants in the first 18 months of (corrected) age and investigate factors associated with gross motor development.

Study design

A longitudinal study was conducted with convenience samples of 58 preterm infants born ≤ 29 weeks of gestation and 52 control full-term infants in Australia.

Outcome measures

The infants were assessed at 4, 8, 12 and 18 months of (corrected) age using the Alberta Infant Motor Scale (AIMS).

Results

Forty-six preterm and 48 control infants completed all four assessments. The preterm group scored significantly lower on various sub-scores at all age levels. Almost half of the preterm infants demonstrated less progression in the sit sub-scale from 4 to 8 months (corrected) age, possibly due to an imbalance between flexor and extensor strength in the trunk. At 12 and 18 months of (corrected) age, lack of rotation and fluency in their movements were evident in some preterm infants. Presence of intra-ventricular haemorrhage and chronic lung disease were associated with poor motor performance at 4 months and use of postnatal steroids was associated with poor motor performance at 4, 8 and 18 months of corrected age.

Conclusion

The imbalance between flexor and extensor muscle strength in preterm infants had a stronger impact on motor development than usually expected. The AIMS appears to be a sensitive assessment tool to demonstrate the unique movement characteristics in this preterm cohort.     

Postnatal growth of preterm born children ≤ 750g at birth

Background

Extremely low birth weight (ELBW) infants are at risk of impaired postnatal growth. Impaired postnatal growth has been reported to be associated with delayed cognitive and motor development.

Aims

To describe postnatal growth patterns of appropriate and small for gestational age (AGA and SGA) ELBW children in relation to their cognitive and motor outcome at age 5.5.

Study design

Retrospective cohort study.

Subjects

One hundred one children with a BW ≤ 750 g, born between 1996 and 2005 in the University Hospital Utrecht, The Netherlands.

Outcome measures

Height (Ht), weight (Wt), occipital-frontal circumference (OFC) at birth, 15 months and 2 years corrected age and 3.5 and 5.5 years.Cognitive and motor outcome at 5.5 years of age, classified as normal (Z-score ≥−1), mildly delayed (−2 ≤ Z-score <−1) or severely delayed (Z-score <−2). AGA (Ht, Wt or OFC at birth ≥−2 SDS) infants were compared with SGA (Ht, Wt or OFC at birth <−2 SDS) infants.

Results

Between birth and 5.5 years catch-up growth in Ht, weight for height (Wt/Ht), Wt and OFC was seen in 72.2%, 55.2%, 28.6% and 68.9% respectively of the SGA infants. For AGA infants we found substantial catch-down growth in Ht (15.4%) and Wt (33.8%). Cognitive and motor outcome was normal in 76.2% and 41.6% of the 101 children. A significantly higher percentage of normal cognitive outcome was found in AGA infants with Wt growth remaining at ≥−2 SDS compared to AGA infants with catch-down growth (83% vs 63%). Next, SGA infants who caught-up in OFC had a higher prevalence of normal cognitive outcome compared to SGA infants who did not catch-up in OFC. Furthermore, a higher percentage of severely delayed motor outcome was found in SGA infants without catch-up growth in Wt compared to SGA infants who caught-up in Wt (61.5% vs 32.2%).

Conclusions

Catch-up growth in Ht, Wt/Ht and OFC occurred in the majority of the SGA infants with a BW ≤ 750 g, but was less common in Wt. AGA children who remained their Wt at ≥−2 SDS have a better cognitive and motor developmental outcome at 5.5 years of age. Catch-up growth in OFC was associated with a better cognitive outcome at 5.5 years of age.     

A longitudinal study of differences in electroencephalographic activity among breastfed, milk formula-fed, and soy formula-fed infants during the first year of life

Background

The extent to which adequate nutrition from infant diets differentially influence developmental outcomes in healthy infants has not been determined.

Aim

To compare the effects of the major infant diets on the development of brain electrical activity during infancy.

Study design

Scalp EEG signals (124 sites) recorded from the same infants during quiet wakefulness at 3, 6, 9, and 12 months.

Subjects

Healthy, full-term infants (40/group; gender matched) either breastfed (BF) or fed milk formula (MF) or soy formula (SF) through the first 6 months.

Outcome measures

Power spectral values for frequencies in the 0.1-30 Hz range.

Results

Significant diet-related differences were present across frequency bands and included effects that were time- [peaks in 0.1-3 Hz at 6 (MF,SF) and 9 months (BF); 3-6 Hz at 6 months (MF, SF > BF); increases in 6-9 Hz from 3 to 6 months (MF > BF) and from 6 to 9 months (MF > SF)] and gender-related (9-12 Hz and 12-30 Hz: at 9 months BF > MF, SF boys, and MF > SF girls).

Conclusions

The development of brain electrical activity during infancy differs between those who are breastfed compared with those fed either milk or soy formula, but is generally similar for formula-fed groups. These variations in EEG activity reflect diet-related influences on the development of brain structure and function that could put infants on different neurodevelopmental trajectories along which cognitive and brain function development will proceed.     

Echocardiography predicts closure of patent ductus arteriosus in response to ibuprofen in infants less than 28 week gestational age

Background

Patent ductus arteriosus (PDA) is a frequent problem in preterm infants, and its incidence is inversely correlated with gestational age. The efficacy of medical treatment decreases with decreasing gestational age (GA), and failure rates as well as ductus ligation rates of 40% have been reported in < 28 week GA newborns. The aim of this study was to determine whether echocardiographic parameters can predict response to ibuprofen treatment of PDA.

Study design

In a longitudinal study, 29 infants born < 28 week GA were screened for a significant PDA (left atrial to aortic root ratio > 1.4, anterior cerebral artery resistance index > 0.8, and oxygen requirement > 35%) at 24-72 h of life and, if a PDA was found, treated with 10-5-5 mg/kg ibuprofen intravenously every 24 h. Ductal parameters were monitored by serial echocardiography. Infant neurodevelopmental outcomes were assessed at 24 month corrected age.

Results

All 15 infants with significant PDA responded to the ibuprofen loading dose indicated by reduced PDA diameters or increased PDA maximum flow velocities (PDA V_max), and 7 patients showed an ongoing response resulting in a closed PDA after the 1st cycle (47%). Of the 8 non-responders, 7 received a 2nd cycle with 2 further responders (29%). All non-responders to the 2nd course had a PDA V_max ≤ 180 cm/s and increasing ductal diameters after the 3rd ibuprofen dose of the 1st course.

Conclusion

Maximum flow velocity and diameter of the PDA at the end of the 1st cycle discriminate between responders and non-responders to further ibuprofen treatment.