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Fetal Behaviour: A Neurodevelopmental Approach is a scholarly and well-referenced text. The opening chapter describes the evolution of studies on fetal behaviour starting with The Fels Longitudinal Study which began in 1930 and was based at Yellow Springs, Ohio. The huge range of information obtained using a tambour attached to the maternal abdomen and linked to a recording device, together with auscultation of the fetal heart reflects the perseverance of the researchers. The development of modern methods of assessing fetal behaviour is explained including ultrasound and dynamic and functional magnetic resonance imaging.

‘Why do fetuses move in the first place?’ is the question posed in a comprehensive chapter on spontaneous fetal movements. We learn that movement is necessary for the development of the nervous system; for example it facilitates the distribution of neurotransmitter receptors on muscle fibres and the pattern of synaptic contacts. The notion that structure must precede function is thereby turned on its head. The gestational age at which different types of fetal movements are first observed by ultrasound is neatly summarised, including reference to the emergence of different types of embryonic motility from 7 to 10 weeks as detected by transvaginal ultrasound.

A CD containing 26 high-quality video recordings of fetal activity is compulsive viewing and is provided with the book.

Variability in the occurrence of fetal activity may be partly explained by different fetal behavioural states. The authors refer to four states defined by fetal heart rate patterns (band width and accelerations), the presence or absence of eye movements, and the periodicity of gross movements. The developmental course of the behavioural states is described and the many factors that can influence them including maternal glucocorticoids, alcohol, and caffeine intake.

The older view that fetuses are passive beings who spend all day simply floating in liquor is readily dispelled by an intriguing chapter on fetal responsiveness which addresses hearing, pain, taste and smell, and touch (as studied by fetal contacts between twins). Important qualities of responsiveness such as memory, habituation, and classical conditioning are also helpfully discussed.

A particularly relevant chapter for clinicians is one that addresses determinants of fetal behaviour. It is not surprising that many structural malformations, especially those affecting the central nervous system, are associated with abnormal fetal behavioural characteristics. The authors enlarge on the influence of fetal position, abnormalities of amniotic fluid volume, maternal hypertension, drugs (therapeutic and drugs of habituation), and maternal emotions.

Interest in the routine ‘non-stress test’ and the ‘biophysical profile’ as tests of fetal health has probably declined in recent years. This may be the result of improved neonatal care, culminating in a less critical approach to the timing of delivery in intrauterine growth restriction with a trend towards earlier intervention. The authors draw attention to the importance of fetal behavioural states in influencing the results of tests of fetal well-being.

An apparent reduction in fetal movements in the third trimester is a relatively common presentation. Research into simplified tests of fetal neurobehaviour that can be applied, interpreted, and ‘outcome tested’ at a clinical level would be one way of harnessing some of the information accrued in this excellent and informative book.

Given the wide range of behaviours already apparent in fetuses it is not surprising that the newborn infant is born with neurobehavioural competencies. We can use our skills as examiners to demonstrate those competencies rather than relying on imaging. The 4th Edition of the Neonatal Behavioural Assessment Scale (NBAS) brings us up to date with the administration of the assessment and the scoring system of the NBAS and explains its concept.

I've approached the book as a neonatologist whose interest is essentially clinical with an interest in neurodevelopmental outcomes. In that respect I'm very aware that the routine neurological examination of the newborn is often poorly conducted and unhelpful.

Permeating the pages of this new edition is considerable enthusiasm for the NBAS and so it is important to understand the conceptual basis of the assessment, which is explained in the opening chapter and referred to in later chapters. It was designed to show the competency of newborn infants not simply in isolation but in their capacity to interact with their parents and the examiner, so developing an integrated pattern of behaviour over time. By engaging parents it helps them understand their infant, gives them self-confidence, and promotes attachment. It may predict later neurodevelopmental outcome and is a useful research tool to study the effect of the intrauterine environment and influences in very early infancy.

The two chapters on the standard administration and scoring system used for the NBAS are explicit and well-illustrated by photographs. Briefly, the NBAS examines four types of behaviour: habituation, motor-oral, truncal, vestibular, and social interactive. Each of these ‘packages’ encompasses a range of tests. Moreover, the scoring system is profoundly influenced by six defined states (deep sleep, light sleep, drowsy, awake with minimal motor activity, awake with considerable motor activity, and crying). I can certainly understand why formal training is needed for conduct of the examination.

Potentially confusing are several variants of the NBAS designed for specific purposes. For example, there is a chapter describing how the behavioural assessment may be combined with routine physical neonatal examination while engaging parents narratively (Physical and Behavioural Newborn Examination).

A huge amount of thought and endeavour has gone into the development of Brazelton's NBAS since its first publication in 1973. Dr Brazelton's hope, expressed in his preface, is that the NBAS or a simplified variant will become widely implemented. I share that view and the extensive references in this book testify to the use of NBAS as an important tool to study the emergence of newborn infants as social beings and their complex interaction with their caregivers.

The questions that are not fully answered for me in this book is whether or not there is compelling scientific evidence that NBAS assessments facilitate parental self-confidence and improved parenting compared with other methods of parental counselling. Can NBAS assessments highlight deviations that cause concern and that can be improved by interventions? To what extent can NBAS assessments predict neurobehavioural outcomes in later infancy and beyond?

Enthusiasts might well draw attention to different studies that purport to answer my questions. However, given the time spent training to carry out the assessment and the time taken for the assessment itself, it should not be a huge additional burden to conduct randomized controlled trials exposing one group of newborn infants to NBAS assessments and another group to an alternative intervention.

If the evidence is already there then I look forward to the next edition of this informative book focussing on those trials and showing what we can learn from them. If there is a gap in the conduct of research trials then the future lies with recommendations on the studies that need to be undertaken. Engaging parents is of course important but if we are to fulfil Dr Brazelton's hope for a wider implementation of the NBAS assessment then we need to engage neonatologists and paediatricians in a research language with which they are familiar.