The neonatal examination

A thorough perinatal examination is the most commonly performed systematic assessment in paediatric practice. All medical undergraduates, graduates and paediatric postgraduates should be able to perform a thorough ‘baby check’. If there is ever a shortage of children with impressive signs around examination time, there is always a ready supply of neonates in level 2 nurseries, ideally suited to having a comprehensive baby check performed. The examination is standard irrespective of the gestation of the infant, although the interpretation of neurobehavioural findings requires a thorough knowledge of the variations between different gestational ages. The gestational age can be assessed by the Ballard method; this is indicated where the gestational age is in doubt, but is fairly complicated and not covered in this section. The object of this section is to provide a framework for the perinatal examination that is easy to remember. Only a limited sample of possible findings is given here, as a comprehensive discussion could double this book’s extent. Entire books can be, and have been, devoted to the examination of the newborn.

In hospital practice, ideally three checks are performed. An initial screening check is performed in the delivery room, assessing the baby’s adaptation to the extrauterine environment. This includes assessing the Apgar scores at 1 and 5 minutes, noting any life-threatening conditions, obvious dysmorphic features (e.g. Down syndrome), gross congenital anomalies (e.g. neural tube defects), any birth injuries and counting the umbilical cord vessels, making sure there are two arteries and one vein.

The second check should be the later comprehensive examination, within the first 24 hours of life. This is the check that must be done, irrespective of the introduction, in a neonate. The order of the examination is variable, depending on what the baby is doing at the time. Generally babies are quieter at the beginning of the examination, so always auscultate the heart first, before palpating anywhere else and disturbing the baby. The check may be approached in a somewhat opportunistic fashion: if the baby’s eyes are open when first approached, check the eyes and red light reflexes (with the ophthalmoscope set at +10); if the baby yawns or cries with a wide open mouth, take your torch and check the pharynx. Do not palpate or move the baby until the cardiorespiratory auscultation is complete: crying does not interfere very much with the remainder of the check.

After listening to the heart, listen to the chest and then palpate the abdomen and the femoral arterial pulsations in particular. Then re-inspect, checking the baby from head to toe, but leave the less pleasant aspects until later (such as checking the mouth and palate with a spatula, checking the red reflex when the baby will not open his or her eyes, checking the hips). A detailed approach is given below.

A third check is required. This may be done in hospital on day 5, but is usually performed by the local doctor at 5–10 days of age. This examination should repeat the comprehensive examination, but with particular emphasis on the following:

At this examination the urine and stool outputs are noted, and growth parameters are repeated as well, checking for adequate weight gain and feeding.

Inspect: growth, colour, respirations, posture, movements, cry

The initial thorough examination commences with inspection. Note the baby’s weight, length, head circumference and nutritional status (muscle bulk, fat). Note the colour (peripheral cyanosis is common) and the respiratory rate (normal being 40–60 breaths per minute; periodic breathing is normal) and depth (retraction indicates some respiratory distress). Causes of tachypnoea include primary respiratory disorders (e.g. hyaline membrane disease, transient tachypnoea of the newborn, meconium aspiration, congenital pneumonia, pneumothorax), space-occupying lesions (e.g. diaphragmatic hernia, congenital cystic lung lesions) or non-respiratory systems: cardiac (e.g. shunts, left-heart obstructive lesions, myocardial disease, arrhythmias), metabolic (e.g. hypoglycaemia), infective (e.g. septicaemia) or haematological causes (e.g. anaemia, polycythaemia). Stridor may be noted with upper airway obstruction. It may be purely inspiratory if the obstruction is extrathoracic, and may involve expiration if intrathoracic. The causes are usually divided into site, intraluminal (e.g. meconium, mucus, blood or milk), intramural (e.g. subglottic oedema from overenthusiastic tracheal suctioning) or extramural (e.g. vascular ring). For more details, see the short case on stridor in Chapter 15 (The respiratory system).

Posture, quality of movement and nature of cry are noted. The gestation of the infant must be considered with respect to posture. Normal full-term neonates usually lie with their hips abducted and slightly flexed, their knees flexed and their upper limbs adducted, with flexion at the elbow and clenching of the fists (not tight), with fingers covering the thumb. Term babies with significant hypotonia may lie with their hips and thighs in the ‘frog’s legs position’ (see the floppy infant case in Chapter 13, Neurology). Babies with serious intracranial pathology may lie with extended necks (opisthotonic posture), obligate flexion of thumbs or scissored lower limbs. Very premature infants (less than 30 weeks) normally have minimal flexor tone, like a rag doll; by 34 weeks, flexor tone appears in the lower limbs, and by 36 weeks in the upper limbs as well. A formal gestational assessment should be undertaken if the gestation is in doubt and the infant seems hypotonic, so as not to overinterpret normal findings of prematurity.

Normal movements may include alternating movements in all limbs, myoclonic jerks when asleep (sleep myoclonus) and jaw tremors when crying. Paucity of movement can occur in neuromuscular diseases (see the floppy infant case in Chapter 13). Involuntary movements can include tremulousness or ‘jitters’ (which can be stopped by gentle pressure) and seizures (may be subtle, tonic or more often focal, irrespective of the underlying pathology, and cannot be stopped by pressure, clearly differentiating them from jitters). Jitters can occur with hypoglycaemia, hypocalcaemia, sepsis and neonatal abstinence syndrome (NAS). Seizures can be due to neonatal encephalopathy (formally termed hypoxic ischaemic encephalopathy), intracranial haemorrhage, meningitis, metabolic causes (hypoglycaemia/hyponatraemia/hypocalcaemia/hypomagnesaemia; hypernatraemia/hyperammonaemia; kernicterus, various inborn errors, pyridoxine deficiency), developmental brain disorders and NAS, or can be idiopathic.