Obtaining the History

Table 4–1 lists the important issues to ask about when obtaining any antenatal history.

TABLE 4–1 Significant issues to ask about when taking the History for a Newborn

Approach to Physical Examinations of the Newborn: When, Why, and How

The first examination

Every newborn infant should be examined at least twice during the first few days of life. An additional examination after discharge but within the first week is recommended, particularly if the mother and infant are discharged from the hospital prior to 48 hours postnatally. If possible, perform the first assessment in the hospital’s delivery area to (1) identify any obvious major and minor congenital malformations, (2) assess gestational age, nutritional status, and vigor, and (3) determine how well the baby handles the transition from intrauterine to extrauterine life.

Most babies make the major physiologic adaptations of this transition smoothly. The few who do not adapt normally—particularly those born prematurely or after perinatal stress or asphyxia—will need help to adapt successfully.

Key Point

The 1-minute Apgar score should not be used to determine if resuscitation should be started. Resuscitation, if needed, should start immediately.

The method used almost universally in delivery rooms to evaluate the central nervous system (CNS) status and general adaptation of the neonate to extrauterine life is the Apgar score. This scoring system, summarized in Table 4–2, evaluates the baby in five different respects: heart rate, respiration, color, muscle tone, and reflex irritability (response to stimulation). These signs are usually evaluated at 1 minute and 5 minutes after birth. The Apgar score is the total of the baby’s scores for each of the five signs. To be consistent, have the Apgar score recorded by an experienced clinical observer whose principal responsibility is caring for and evaluating the baby. Because inter-observer variation in scoring may be considerable, experience is essential. Evaluate the signs at exactly 1 minute and 5 minutes to establish the score, especially in relation to muscle tone and reflex irritability. The latter is usually elicited by firmly stroking the sole of the foot; the appropriate response to this stimulation is a vigorous cry.

TABLE 4–2 Parameters of Evaluation using the Apgar Score

Recording the Apgar score serves two purposes. First, it ensures a careful evaluation of the baby during the immediate newborn period. Second, it helps to determine the presence and level of CNS depression and whether there is a need to continue resuscitation. In babies who need resuscitation, serial scores measured at 1, 2, 5, and even 10 minutes furnish a semi-quantitative method of recording recovery. The relationship between low Apgar scores and neurologic abnormality later in infancy is not reliable.

The Apgar scoring system produces more than just a number. The presence or absence of individual signs should tell you not just that an infant had an “Apgar 6” but that this score was assigned because certain functions were absent or suboptimal. For example, a baby with congenital neuromuscular disease may score well for heart rate, respiratory effort, and color but poorly for muscle tone and reflex irritability. A preterm infant scores lower than a full-term baby because an immature baby’s muscle tone is always less than that of a normal-term infant.

The accurate diagnosis of perinatal asphyxia is not easy and requires not only evaluation of the clinical condition at birth but also evaluation of umbilical cord arterial blood gases and subsequent clinical neurologic sequelae in the newborn period (hypoxic-ischemic encephalopathy). Low Apgar scores may be caused by many conditions affecting the baby, such as sepsis, neuromuscular disorders, and perinatal asphyxia.

Key Point

Do not use the Apgar score as a means of defining asphyxia. A low score does not necessarily indicate asphyxia.

Clinical Observations and What They Mean

Encourage the parents to participate as much as possible in the examination by undressing the baby, holding the baby on the lap or the bed, and providing a stabilizing finger for the baby to grasp (Fig. 4–1). The first part of the examination is the most important. Do not touch the baby except to remove all clothing gently. You may wish to leave the diaper on until you are ready to examine the lower portion of the baby. The baby should be undressed, warm, and well illuminated and should be helped to feel stable and secure on the examining surface. Improving the baby’s stability and relaxation by letting him or her grasp the parent’s or your finger allows an immediate appreciation of the strength of the baby’s reflex grasp and reduces the tendency for instinctive startle reflexes that occur when the baby feels unstable and rolls on the examining surface.

FIGURE 4–1 The newborn feels more stable and tends to relax if you allow the infant to hold your hand during the examination.

The ideal time to examine a newborn is a couple of hours after a feeding, when the baby may not be too deeply asleep, as babies often are just after a feeding, nor awake and screaming, as they often are just before a feeding. Stand back and take a long hard look at the infant; educated observation often reveals far more than touching, poking, and kneading. While observing the newborn, answer the following questions:

FIGURE 4–2 Cutis marmorata (“marble skin”) can occur as a normal phenomenon when the baby is exposed.

Look for hematomas, hemangiomas, ecchymoses, and petechiae. The last can be associated with increased intravascular pressure during delivery, thrombocytopenia from the presence of platelet antibodies, or congenital infections. Cutaneous hemangiomas are often absent or minimally apparent at birth but develop and grow during the first weeks or months of life, only to regress spontaneously later. Ecchymoses may indicate more than usual trauma or an underlying coagulation disorder.

You can perform much of the newborn’s neurologic examination without touching the baby. Do all four extremities move equally and maintain a general posture of flexion, with alternating flexion and extension movements? The eyes should move if they are open, and the baby may exhibit sucking and tongue movements, yawning, facial grimacing, and spontaneous startle responses. The four most important parts of the neurologic assessment are:

A baby’s level of alertness varies with the time of day and the time of last feeding; normal newborns spend about 20 out of 24 hours asleep. Visual alertness is temporarily limited if erythromycin ointment has been instilled in the eyes as prophylaxis for gonococcal ophthalmia.

Listening To the Cry

Babies normally cry when they are uncomfortable, disturbed, or hungry. Train yourself to listen carefully to infant cries, because there is much to be learned from them. The normal cry should be strong; hoarseness, weakness, or an unusually high-pitched or low-pitched cry may indicate laryngeal or neurologic abnormalities. Repetitive inconsolable crying also is abnormal. An experienced nurse or mother can quickly tell you whether a particular baby’s cry is normal. Sometimes the nurse or mother is the first to suspect a disorder simply on the basis of an unusual cry, such as the high-pitched “cerebral” cry; the low throaty cry of congenital hypothyroidism; the characteristic catlike cry of the cri du chat syndrome; or the weak, poorly sustained cry of the infant who is sick.

Muscle Tone

By carefully examining many babies, you will become familiar with the differences between normal, increased, and diminished muscle tone in newborns. The differences cannot be described in words. Only by making it a regular practice to flex and extend babies’ arms and legs repeatedly during every examination of newborns can you develop an instinctive “feel” for normal, increased, and decreased muscle tone. When a newborn baby is pulled to the sitting position from the supine, the head lags behind the trunk; a healthy full-term baby makes some effort to bring the head in line with the chest. Once lifted to a sitting position, a full-term infant can keep the head upright for several seconds.

Primitive Reflexes

Many so-called primitive reflexes can be elicited that may already have been observed during the earlier part of the examination.

Moro reflex

Newborns often demonstrate the Moro, startle, or embrace reflex spontaneously when they are suddenly moved, exposed to a sudden loud noise, given the feeling of falling, or feel unstable on a flat surface. You can most reliably elicit this reflex by allowing the infant’s head to drop (while supporting it gently) below the level of the rest of the body while the baby is in a reclining position. The baby extends the arms suddenly and rapidly with the hands open, then brings them back together more slowly in a movement that looks like an embrace. The initial rapid movement may be accompanied by a grimace or cry (Fig. 4–3). Symmetry of movement is important. Weakness of one arm (e.g., in an infant with brachial plexus injury) results in an asymmetric Moro reflex.

FIGURE 4–3 Induce the Moro or “embrace” reflex by giving the infant the feeling of falling. The response begins with a sudden extension of the arms and legs (A), which is followed by a slower embracing movement in which the arms are brought together (B). The Moro reflex is sometimes accompanied by a cry.

Palmar grasp

Find the palmar grasp by placing your index fingers in each of the baby’s open hands; the baby’s fingers should close around your fingers with strength enough to lift the baby’s body part of the way off the bed or table (Fig. 4–4).

FIGURE 4–4 In the newborn, the prehensile grasp of the fingers is often strong enough to support the baby’s weight.

Plantar grasp

A strong plantar grasp usually can be demonstrated if you place your thumb on the sole of the baby’s foot in the space under the toes (Fig. 4–5).

FIGURE 4–5 The plantar grasp typically is strongest in the newborn period.

Weighing and Measuring

For the physician’s and the parents’ records, it is important to (1) measure the baby’s head circumference, length, and weight accurately and (2) assess the nutritional status. Measure the head circumference, preferably with a disposable tape measure, around the largest occipital-frontal diameter across the forehead, just above the eyes, and over the most prominent part of the occiput (Fig. 4–6). Head circumference normally measures 33 to 37 cm in a full-term infant. If a baby’s head circumference measures slightly above or below the normal for age, check the parents’ head circumferences before “pushing the panic button.” Benign familial megalencephaly, a normal variant, is the most common cause of a larger than average head. The condition can be verified by checking the head circumference of both parents. Megalencephaly is usually handed down by the father.

FIGURE 4–6 Measuring the head circumference of an infant.