Neurological and visual assessments in very and late low-risk preterm infants

Early Neurological Assessment and Long-Term Neuromotor Outcomes in Late Preterm Infants: A Critical Review

Background and Objectives: Late preterm (LP) infants (born between 34 and 36 weeks of gestational age) are considered at higher risk of neonatal morbidities, mortality, and neurological impairments than full-term born infants (FT). The aim of this study was to provide a critical review of the literature outlining the different aspects of neurological function reported both in the neonatal period and in the follow up of late preterm infants. Materials and Methods: A comprehensive search of the MEDLINE, Embase, PsycINFO, and CINAHL electronic databases was made, using the following search terms: ‘Late preterm infants’, ‘Near term infants’, ‘neurological assessment’, ‘neurological outcome’, ‘neuromotor outcome’, cerebral palsy’, ‘CP’, ‘motor impairment’, including all the studies reporting clinical neurological assessment of LP (including both neonatal period and subsequent ages). Results: A total of 35 articles, comprising 301,495 children, were included as fulfilling the inclusion criteria: ten reported neonatal neurological findings, seven reported data about the first two years after birth, eighteen reported data about incidence of CP and motor disorder during the infancy. Results showed a more immature neurological profile, explored with structured neurological assessments, in LP infants compared with FT infants. The LP population also had a higher risk of developing cerebral palsy, motor delay, and coordination disorder. Conclusion: LP had a higher risk of neurological impairments than FT infants, due to a brain immaturity and an increased vulnerability to injury, as the last weeks of gestational age are crucial for the development of the brain.

Neonatal neurological examination during the first 6h after birth

BACKGROUND

Few neurological assessments are easily performed during the first 6h after birth.

AIMS

To assess a cohort of low risk term born newborns within the first 6h and at 48h after birth using the Hammersmith Neonatal Neurological Examination.

STUDY DESIGN AND SUBJECTS

A population of low risk term born newborns was examined within 3h from birth or between 3 and 6h. Each infant was re-assessed at 48h, establishing the range and frequency distribution of neonatal neurological scores at each time point.

RESULTS

Of the 124 full-term born newborns, 62 were assessed at 0-3h and 62 at 3-6h. All infants were re-assessed at 48h. For 23/34 of the neurological items, the range and median scores were similar across the 3 time points. In the remaining 11 items the three groups had a similar range of scores but the median scores were different with different rates of changes. In 6 of the 11 the median scores at 3-6h were similar to those observed at 48h but they appeared to be 'less mature' at 0-3h. Only in one item the median scores were consistently different at the 3 time points.

CONCLUSIONS

Our results suggest that a neurological examination can already be reliably performed soon after birth. These findings will help in the interpretation of the few items that show changes with increasing postnatal age.

A Third-Generation Lipid Emulsion that Contains n-3 Long-Chain PUFAs Preserves Retinal Function in Parenterally Fed Neonatal Piglets

BACKGROUND

Preterm neonates and those with intestinal failure require prolonged parenteral nutrition (PN) during a critical time of early central nervous system maturation. Conventional lipid emulsions fed to preterm neonates lack n-3 (ω-3) long-chain polyunsaturated fatty acids (LC-PUFAs; >20 carbon chain in length). Recently, fish oil lipid emulsions have been developed that provide both n-6 (ω-6) and n-3 LC-PUFAs, precursors of very long-chain PUFAs (VLC-PUFAs; >24 carbon chain in length).

OBJECTIVE

Our objective was to determine the effect of fish oil lipid on retinal function in neonatal piglets fed total PN with the use of the lipid emulsions available in clinical practice. We hypothesized that fish oil-containing parenteral lipid would preserve retinal function more than conventional parenteral lipid.

METHODS

Male neonatal piglets (2-5 d of age) were fed isonitrogenous (16 g · kg^-1 · d^-1), isocaloric (1.1 MJ · kg^-1 · d^-1) PN that varied only in the lipid emulsion: Intralipid or SMOFlipid at 10 g · kg^-1 · d^-1 (n = 8/group). Retinal function was assessed after 14 d of treatment by recording electroretinograms under various light intensity conditions. Retinas were then harvested for histology and to determine fatty acid composition.

RESULTS

Electroretinogram intensity response curves showed greater photoreceptor a-wave amplitude in piglets fed SMOFlipid than in those fed Intralipid (percentage), for postsynaptic depolarizing bipolar cell b-waves (percentage) and for flicker electroretinogram amplitudes (percentage) (P < 0.05). Compared with those fed Intralipid, SMOFlipid-fed piglets had greater retinal total n-3 LC-PUFAs (15.7% compared with 18.4%; P = 0.04) and n-3 VLC-PUFAs (0.9% compared with 1.5%; P = 0.02), whereas Intralipid-fed piglets had greater total n-6 LC-PUFAs (13.1% compared with 10.5%; P < 0.01) and n-6 VLC-PUFAs (0.7% compared with 0.5%; P = 0.01). Histologically, retinas were indistinguishable between groups.

CONCLUSIONS

In a neonatal piglet model of PN feeding, the inclusion of fish oil-based n-3 LC-PUFAs in the lipid emulsion leads to their accretion and endogenous elongation to VLC-PUFAs in the retina, which is associated with better retinal function.

PREMM: preterm early massage by the mother: protocol of a randomised controlled trial of massage therapy in very preterm infants

Background

Preterm infants follow an altered neurodevelopmental trajectory compared to their term born peers as a result of the influence of early birth, and the altered environment. Infant massage in the preterm infant has shown positive effects on weight gain and reduced length of hospital stay. There is however, limited current evidence of improved neurodevelopment or improved attachment, maternal mood or anxiety. The aim of this study is to investigate the effects of infant massage performed by the mother in very preterm (VPT) infants. Effects on the infant will be assessed at the electrophysiological, neuroradiological and clinical levels.  Effects on maternal mood, anxiety and mother-infant attachment will also be measured.

Methods/Design

A randomised controlled trial to investigate the effect of massage therapy in VPT infants. Sixty VPT infants, born at 28 to 32 weeks and 6 days gestational age, who are stable, off supplemental oxygen therapy and have normal cranial ultrasounds will be recruited and randomised to an intervention (infant massage) group or a control (standard care) group. Ten healthy term born infants will be recruited as a reference comparison group. The intervention group will receive standardised massage therapy administered by the mother from recruitment, until term equivalent age (TEA). The control group will receive care as usual (CAU). Infants and their mothers will be assessed at baseline, TEA, 12 months and 24 months corrected age (CA), with a battery of clinical, neuroimaging and electrophysiological measures, as well as structured questionnaires, psychoanalytic observations and neurodevelopmental assessments.

Discussion

Optimising preterm infant neurodevelopment is a key aim of neonatal research, which could substantially improve long-term outcomes and reduce the socio-economic impact of VPT birth. This study has the potential to give insights into the mother-baby relationship and any positive effects of infant massage on neurodevelopment. An early intervention such as massage that is relatively easy to administer and could alter the trajectory of preterm infant brain development, holds potential to improve neurodevelopmental outcomes in this vulnerable population.

Trial registration

Australian New Zealand Clinical Trials Registry: ACTRN12612000335897. Date registered: 22/3/2012.

Neonatal neurological examination of late preterm babies

BACKGROUNDS

Healthy late-preterm (LP) infants examined at term equivalent age showed wider median and range of neurological scores than full-term infants; differences between infants born at 34 and those born at 35-36 weeks were also observed.

AIMS

The aim of this study is to establish the range and frequency distribution of neonatal neurological scores in a cohort of low risk LP infants assessed during the first 3 days from birth.

STUDY DESIGN AND SUBJECTS

118 low-risk infants born between 34 and 36 weeks of gestational age (GA) were assessed between 48 and 72 h from birth.

OUTCOME MEASURES

The full version of the Hammersmith Neonatal Neurologic Assessment and the screening proforma were used to assess all the infants. The raw scores obtained were compared to those of full-term infants using the same examination.

RESULTS

The distribution of neurological scores was similar among the 3 GAs for 26 items, with different median scores among LP infants born at 36 weeks and those born at 34 and 35 in only 2 items. LP infants showed a wider range of findings for each item than that of full term infants assessed soon after birth. Using the screening proforma, in our cohort, for each item the findings falling outside the 90% level were identical to those found in term-born and very preterm infants assessed at term age.

CONCLUSIONS

The neurological scores obtained in our cohort could help as reference data when examining LP infants at birth compared to age matched low risk infants.

Visual function in preterm infants: visualizing the brain to improve prognosis

Considerable development of the visual system occurs in the third trimester of life, a time when very preterm-born infants are in a neonatal intensive care unit (NICU). Their very early birth during a period of rapid and marked neurodevelopment and their clinical course makes them a very high-risk population. A range of different events impacts brain development and the visual system, leading to significant long-term visual dysfunction. Improved neuroimaging techniques provide an important window on the early brain and visual system development of these vulnerable infants. Greater understanding of the etiology of visual impairment subsequent to preterm birth and the timing of critical processes will allow early recognition and the earlier implementations of interventions. In the longer term, this will help clinicians optimize NICU practice to reduce the incidence of visual dysfunction in these children.

Fatores associados ao atraso do desenvolvimento motor de crianças prematuras internadas em unidade de neonatologia

OBJETIVOS: verificar a frequência do atraso do desenvolvimento motor em crianças prematuras internadas em unidade neonatal e identificar os fatores associados. MÉTODOS: estudo descritivo e analítico, realizado na Unidade Neonatal de uma maternidade de alto risco em Recife, Brasil. Avaliou-se o desenvolvimento motor, através do Test of Infant Motor Performance, de 98 crianças nascidas pré-termo com idade pós-conceptual mínima de 34 semanas, durante a internação, entre janeiro e julho de 2009. Analisaram-se associações entre variáveis maternas, neonatais e assistenciais com desenvolvimento motor. RESULTADOS: a média de idade pós-conceptual na avaliação foi de 37 semanas e 39,8% das crianças apresentaram desenvolvimento motor alterado (atípico ou suspeito). Fatores significativamente associados ao desenvolvimento motor alterado foram: menor peso ao nascer; maior idade na avaliação; maior número de consultas pré-natais; ocorrência de hipóxia e displasia broncopulmonar; maior tempo de permanência na unidade de terapia intensiva e unidade neonatal. Houve tendência significante a um pior desenvolvimento motor com uso de oxigenoterapia e ventilação mecânica prolongadas. CONCLUSÕES: crianças prematuras internadas podem apresentar atraso precoce do desenvolvimento motor, de forma grave ou limítrofe. Peso ao nascer, morbidades neonatais e assistência recebida na unidade neonatal foram os fatores que mais influenciaram o desfecho. Esses resultados justificam o início de estratégias preventivas e estimulação ainda no período de internação.