WK9: The Newborn
The Newborn
It is not unusual to hear the comment “all newborns look alike” from people viewing a nursery full of babies. In actuality, every child is born with individual physical and personality characteristics that make him or her unique right from the start.
I. Vital Statistics
Vital statistics measured in a newborn are weight, length, and head and chest circumference. Be sure all health care providers involved with newborns are aware of safety issues specific to newborn care when taking these measurements such as not leaving a newborn unattended on a bed or scale.
Weight
The birth weight of newborns varies depending on the racial, nutritional, intrauterine, and genetic factors that were present during conception and pregnancy. The weight in relation to the gestational age should be plotted on a standard neonatal graph, this way helps identify newborns who are at risk because of their small size. This information also separates those who are small for their gestational age (newborns who have suffered intrauterine growth restriction) from preterm infants (infants who are healthy but small only because they were born early).
Plotting weight in conjunction with height and head circumference is also helpful because it highlights disproportionate measurements. For example, a newborn who falls within the 50th percentile for height and weight but whose head circumference is in the 90th percentile may have abnormal head growth. A newborn who is in the 50th percentile for weight and head circumference but in the 3rd percentile for height may have a growth problem.
The average birth weight (50th percentile) for a white, mature female newborn in the United States is 3.4 kg (7.5 lb); for a white, mature male newborn, it is 3.5 kg (7.7 lb). Newborns of other races weigh approximately 0.5 lb less. The arbitrary lower limit of normal for all races is 2.5 kg (5.5 lb).
Birth weight exceeding 4.7 kg (10 lb) is unusual, but weights as high as 7.7 kg (17 lb) have been documented. If a newborn weighs more than 4.7 kg, the baby is said to be macrosomic and a maternal illness, such as diabetes mellitus, must be suspected (Kwik et al., 2007). Second-born children usually weigh more than first-born. Birth weight continues to increase with each succeeding child in a family.
After this initial loss of weight, a newborn has 1 day of stable weight, then begins to gain weight. The breastfed newborn recaptures birth weight within 10 days; a formula-fed infant accomplishes this gain within 7 days. After this, a newborn begins to gain about 2 lb per month (6 to 8 oz per week) for the first 6 months of life.
Length
The average birth length (50th percentile) of a mature female neonate is 53 cm (20.9 in). For mature males, the average birth length is 54 cm (21.3 in). The lower limit of normal length is arbitrarily set at 46 cm (18 in). Although rare, babies with lengths as great as 57.5 cm (24 in) have been reported.
Head Circumference
In a mature newborn, the head circumference is usually 34 to 35 cm (13.5 to 14 in). A mature newborn with a head circumference greater than 37 cm (14.8 in) or less than 33 cm (13.2 in) should be carefully assessed for neurologic involvement, although occasionally a well newborn falls within these limits. Head circumference is measured with a tape measure drawn across the center of the forehead and around the most prominent portion of the posterior head.
Chest Circumference
• The chest circumference in a term newborn is about 2 cm (0.75 to 1 in) less than the head circumference. This is measured at the level of the nipples. If a large amount of breast tissue or edema of breasts is present, this measurement will not be accurate until the edema has subsided.
II. Vital Signs
Vital sign measurements begin to change from those present in intrauterine life at the moment of birth
Temperature
The temperature of newborns is about 99° F (37.2° C) at birth because they have been confined in an internal body organ. The temperature falls almost immediately to below normal because of heat loss and immature temperature regulating mechanisms. The temperature of birthing rooms, approximately 68° to 72° F (21° to 22° C), can add to this loss of heat.
A newborn loses heat easily because of difficulty conserving heat under any circumstance. Insulation, an efficient means of conserving heat in adults, is not effective in newborns because they have little subcutaneous fat to provide insulation. Shivering, a means of increasing metabolism and thereby providing heat in adults, is rarely seen in newborns.
Newborns can conserve heat by constricting blood vessels and moving blood away from the skin. Brown fat, a special tissue found in mature newborns, apparently helps to conserve or produce body heat by increasing metabolism. The greatest amounts of brown fat are found in the intrascapular region, thorax, and perirenal area. Brown fat is thought to aid in controlling newborn temperature similar to temperature control in a hibernating animal. In later life, it may influence the proportion of body fat retained.
Newborns exposed to cool air tend to kick and cry to increase their metabolic rate and produce more heat. This reaction, however, also increases their need for oxygen and their respiratory rate increases. An immature newborn with poor lung development has trouble making such an adjustment.
Drying and wrapping newborns and placing them in warmed cribs, or drying them and placing them under a radiant heat source, are excellent mechanical measures to help conserve heat. In addition, placing a newborn against the mother’s skin and then covering the newborn with a blanket helps to transfer heat from the mother to the newborn; this is termed skin-to-skin care.
Pulse
The heart rate of a fetus in utero averages 120 to 160 beats per minute (bpm). Immediately after birth, as the newborn struggles to initiate respirations, the heart rate may be as rapid as 180 bpm. Within 1 hour after birth, as the newborn settles down to sleep, the heart rate stabilizes to an average of 120 to 140 bpm.
The heart rate of a newborn often remains slightly irregular because of immaturity of the cardiac regulatory center in the medulla. Transient murmurs may result from the incomplete closure of fetal circulation shunts. During crying, the rate may rise again to 180 bpm. In addition, heart rate can decrease during sleep, ranging from 90 to 110 bpm.
You should be able to palpate brachial and femoral pulses in a newborn, but the radial and temporal pulses are more difficult to palpate with any degree of accuracy. Therefore, a newborn’s heart rate is always determined by listening for an apical heartbeat for a full minute, rather than assessing a pulse in an extremity.
Respiration
The respiratory rate of a newborn in the first few minutes of life may be as high as 80 breaths per minute. As respiratory activity is established and maintained, this rate settles to an average of 30 to 60 breaths per minute when the newborn is at rest. Respiratory depth, rate, and rhythm are likely to be irregular, and short periods of apnea (without cyanosis) which last less than 15 seconds, sometimes called periodic respirations, are normal.
Respiratory rate can be observed most easily by watching the movement of a newborn’s abdomen, because breathing primarily involves the use of the diaphragm and abdominal muscles.
Blood Pressure
The blood pressure of a newborn is approximately 80/46 mm Hg at birth. By the 10th day, it rises to about 100/50 mm Hg. Because measurement of blood pressure in a newborn is somewhat inaccurate, it is not routinely measured unless a cardiac anomaly is suspected. For an
accurate reading, the cuff width used must be no more than two thirds the length of the upper arm or thigh.
Blood pressure tends to increase with crying (and a newborn cries when disturbed and manipulated by such procedures as taking blood pressure). A Doppler method may be used to take blood pressure
III. Physiologic Function
Cardiovascular System
Changes in the cardiovascular system are necessary after birth because now the lungs must oxygenate the blood that was formerly oxygenated by the placenta. When the cord is clamped, a neonate is forced to take in oxygen through the lungs. As the lungs inflate for the first time, pressure decreases in the pulmonary artery (the artery leading from the heart to the lungs). This decrease in pressure plays a role in promoting closure of the ductus arteriosus, a fetal shunt. As pressure increases in the left side of the heart from increased blood volume, the foramen ovale between the two atria closes because of the pressure against the lip of the structure (permanent closure does not occur for weeks). With the remaining fetal circulatory structures (umbilical vein, two umbilical arteries, and ductus venosus) no longer receiving blood, the blood within them clots, and the vessels atrophy over the next few weeks.
The hematocrit is between 45% and 50%. A newborn also has an elevated red blood cell count, about 6 million cells per cubic millimeter. Once proper lung oxygenation has been established, the need for the high red cell count diminishes. Therefore, within a matter of days, a newborn’s red cells begin to deteriorate. Bilirubin is a byproduct of the breakdown of red blood cells. An indirect bilirubin level at birth is 1 to 4 mg/100 mL. Any increase over this amount reflects the release of bilirubin as excessive red blood cells begin their breakdown.
A newborn has an equally high white blood cell count at birth, about 15,000 to 30,000 cells/mm3 . Values as high as 40,000 cells/mm3 may be seen if the birth was stressful.
Respiratory System
A first breath is a major undertaking because it requires a tremendous amount of pressure (about 40 to 70 cm H2O). It is initiated by a combination of cold receptors; a lowered partial pressure of oxygen (PO2), which falls from 80 to as low as 15 mm Hg before a first breath; and an increased partial carbon dioxide pressure (PCO2), which rises as high as 70 mm Hg before a first breath.
All newborns have some fluid in their lungs from intrauterine life that will ease the surface tension on alveolar walls and allows alveoli to inflate more easily than if the lung walls were dry. About a third of this fluid is forced out of the lungs by the pressure of vaginal birth. Additional fluid is quickly absorbed by lung blood vessels and lymphatics after the first breath.
Once the alveoli have been inflated with a first breath, breathing becomes much easier for a baby, requiring only about 6 to 8 cm H2O pressure. Within 10 minutes after birth, most newborns have established a good residual volume.
A newborn who has difficulty establishing respirations at birth should be examined closely in the postpartal period for a cardiac murmur or other indication that he or she still has patent fetal cardiac structures, especially a patent ductus arteriosus.
Gastrointestinal System
Although the gastrointestinal tract is usually sterile at birth, bacteria may be cultured from the intestinal tract in most babies within 5 hours after birth and from all babies at 24 hours of life. Most of these bacteria enter the tract through the newborn’s mouth from airborne sources. Others may come from vaginal secretions at birth, from hospital bedding, and from contact at the breast. Accumulation of bacteria in the gastrointestinal tract is necessary for digestion and for the synthesis of vitamin K.
The first stool of a newborn is usually passed within 24 hours after birth. It consists of meconium, a sticky, tarlike, blackish-green, odorless material formed from mucus, vernix, lanugo, hormones, and carbohydrates that accumulated during intrauterine life. If a newborn does not pass a meconium stool by 24 to 48 hours after birth, the possibility of some factor such as meconium ileus, imperforate anus, or volvulus should be suspected.
About the second or third day of life, newborn stool changes in color and consistency, becoming green and loose. This is termed transitional stool, and it may resemble diarrhea to the untrained eye. By the fourth day of life, breastfed babies pass three or four light yellow stools per day. They are sweet-smelling, because breast milk is high in lactic acid, which reduces the amount of putrefactive organisms in the stool. A newborn who receives formula usually passes two or three bright yellow stools a day. These have a slightly more noticeable odor, compared with the stools of breastfed babies.
Urinary System
The average newborn voids within 24 hours after birth. A newborn who does not take in much fluid for the first 24 hours may void later than this, but the 24-hour point is a good general rule. Newborns who do not void within this time should be examined for the possibility of urethral stenosis or absent kidneys or ureters.
A single voiding in a newborn is only about 15 mL and may be easily missed in a thick diaper. Specific gravity ranges from 1.008 to 1.010. The daily urinary output for the first 1 or 2 days is about 30 to 60 mL total. By week 1, total daily volume rises to about 300 mL. The first voiding may be pink or dusky because of uric acid crystals that were formed in the bladder in utero; this is an innocent finding.
Immune System
Because they have difficulty forming antibodies against invading antigens until about 2 months of age, newborns are prone to infection. This inability to form antibodies is the reason that most immunizations against childhood diseases are not given to infants younger than 2 months of age. Newborns do have some immunologic protection, because they are born with passive antibodies (immunoglobulin G) from their mother that crossed the placenta. In most instances, these include antibodies against poliomyelitis, measles, diphtheria, pertussis, chickenpox, rubella, and tetanus. Newborns are routinely administered hepatitis B vaccine during the first 12 hours after birth to protect against this disease.
Neuromuscular System
Mature newborns demonstrate neuromuscular function by moving their extremities, attempting to control head movement, exhibiting a strong cry, and demonstrating newborn reflexes. Limpness or total absence of a muscular response to manipulation is never normal and suggests narcosis, shock, or cerebral injury.
REFLEX
Newborn reflexes can be tested with consistency by using simple maneuvers.
Blink Reflex.
A blink reflex in a newborn serves the same purpose as it does in an adult—to protect the eye from any object coming near it by rapid eyelid closure. It may be elicited by shining a strong light such as a flashlight or an otoscope light on an eye. A sudden movement toward the eye sometimes can elicit the blink reflex.
Rooting Reflex.
If the cheek is brushed or stroked near the corner of the mouth, a newborn infant will turn the head in that direction. This reflex serves to help a newborn find food: when a mother holds the child and allows her breast to brush the newborn’s cheek, the reflex makes the baby turn toward the breast. The re Sucking Reflex.
When a newborn’s lips are touched, the baby makes a sucking motion. The reflex helps a newborn find food: when the newborn’s lips touch the mother’s breast or a bottle, the baby sucks and so takes in food. The sucking reflex begins to diminish at about 6 months of age. It disappears immediately flex disappears at about the sixth week of life.
Swallowing Reflex.
The swallowing reflex in a newborn is the same as in the adult. Food that reaches the posterior portion of the tongue is automatically swallowed. Gag, cough, and sneeze reflexes also are present in newborns to maintain a clear airway in the event that normal swallowing does not keep the pharynx free of obstructing mucus.
Extrusion Reflex.
A newborn extrudes any substance that is placed on the anterior portion of the tongue. This protective reflex prevents the swallowing of inedible substances. It disappears at about 4 months of age. Until then, the infant may seem to be spitting out or refusing solid food placed in the mouth Palmar Grasp Reflex.
Newborns grasp an object placed in their palm by closing their fingers on it. Mature newborns grasp so strongly that they can be raised from a supine position and suspended momentarily from an examiner’s fingers. This reflex disappears at about 6 weeks to 3 months of age. A baby begins to grasp meaningfully at about 3 months of age.
Step (Walk)-in-Place Reflex.
Newborns who are held in a vertical position with their feet touching a hard surface will take a few quick, alternating steps. This reflex disappears by 3 months of age. By 4 months, babies can bear a good portion of their weight unhindered by this reflex.
Plantar Grasp Reflex.
When an object touches the sole of a newborn’s foot at the base of the toes, the toes grasp in the same manner as do the fingers. This reflex disappears at about 8 to 9 months of age in preparation for walking. However, it may be present during sleep for a longer period.
Tonic Neck Reflex.
When newborns lie on their backs, their heads usually turn to one side or the other. The arm and the leg on the side toward which the head turns extend, and the opposite arm and leg contract. If you turn a newborn’s head to the opposite side, he or she will often change the extension and contraction of legs and arms accordingly. This is also called a boxer or fencing reflex, because the position simulates that of someone preparing to box or fence. It may signify handedness. The reflex disappears between the second and third months of life.
Moro Reflex.
A Moro (startle) reflex can be initiated by startling a newborn with a loud noise or by jarring the bassinet. The most accurate method of eliciting the reflex is to hold newborns in a supine position and allow their heads to drop backward about 1 inch. In response to this sudden head movement, they abduct and extend their arms and legs. Their fingers assume a typical “C” position. It is strong for the first 8 weeks of life and then fades by the end of the fourth or fifth month, at the same time an infant can roll away from danger.
Babinski Reflex.
When the sole of the foot is stroked in an inverted “J” curve from the heel upward, a newborn fans the toes (positive Babinski sign) (Fig. 18.8). This is in contrast to the adult, who flexes the toes. This reaction occurs because nervous system development is immature. It remains positive (toes fan) until at least 3 months of age, when it is supplanted by the downturning or adult flexion response.
Magnet Reflex.
If pressure is applied to the soles of the feet of a newborn lying in a supine position, he or she pushes back against the pressure. This and the two following reflexes are tests of spinal cord integrity.
Crossed Extension Reflex.
If one leg of a newborn lying supine is extended and the sole of that foot is irritated by being rubbed with a sharp object, such as a thumbnail, the infant raises the other leg and extends it, as if trying to push away the hand irritating the first leg.
Trunk Incurvation Reflex
When newborns lie in a prone position and are touched along the paravertebral area by a probing finger, they flex their trunk and swing their pelvis toward the touch
Landau Reflex.
A newborn who is held in a prone position with a hand underneath, supporting the trunk, should demonstrate some muscle tone. Babies may not be able to lift their head or arch their back in this position (as they will at 3 months of age), but neither should they sag into an inverted “U” position. The latter response indicates extremely poor muscle tone, the cause of which should be investigated.
SENSORS
Vision.
Newborns
see as soon as they are born and possibly have been “seeing” light and dark in utero for the last few months of pregnancy, as the uterus and the abdominal wall were stretched thin.
Newborns demonstrate sight at birth by blinking at a strong light (blink reflex) or by following a bright light or toy a short distance with their eyes.
Touch.
The sense of touch is also well developed at birth. Newborns demonstrate this by quieting at a soothing touch and by sucking and rooting reflexes, which are elicited by touch. They also react to painful stimuli.
Taste.
A newborn has the ability to discriminate taste, because taste buds are developed and functioning even before birth. A fetus in utero, for example, will swallow amniotic fluid more rapidly than usual if glucose is added to sweeten its taste. The swallowing decreases if a bitter flavor is added. A newborn turns away from a bitter taste such as salt but readily accepts the sweet taste of milk or glucose water.
Smell.
The sense of smell is present in newborns as soon as the nose is clear of lung and amniotic fluid.
Newborns turn toward their mothers’ breast partly out of recognition of the smell of breast milk and partly as a manifestation of the rooting reflex. Their ability to respond to odors can be used to document alertness.
IV. Appearance of a Newborn
1. Skin
A. Color
Most term newborns have a ruddy complexion because of the increased concentration of red blood cells in blood vessels and a decrease in the amount of subcutaneous fat, which makes the blood vessels more visible. This ruddiness fades slightly over the first month. Infants with poor central nervous system control may appear pale and cyanotic. A gray color in newborns generally indicates infection. Cyanosis. Generalized mottling of the skin is common. A newborn’s lips, hands, and feet are likely to appear blue from immature peripheral circulation. Acrocyanosis (blueness of hands and feet) is so prominent in some newborns that it appears as if some stricture were cutting off circulation, with usual skin color on one side and blue on the other. Acrocyanosis is a normal phenomenon in the first 24 to 48 hours after birth; however, central cyanosis, or cyanosis of the trunk, is always a cause for concern. Central cyanosis indicates decreased oxygenation. It may be the result of a temporary respiratory obstruction or an underlying disease state
Hyperbilirubinemia
Hyperbilirubinemia leads to jaundice, or yellowing of the skin (Beachy, 2007). This occurs on the second or third day of life in about 50% of all newborns, as a result of a breakdown of fetal red blood cells (physiologic jaundice). The infant’s skin and the sclera of the eyes appear noticeably yellow. This happens because the high red blood cell count built up in utero is destroyed, and heme and globin are released.
Many newborns have such immature liver function that indirect bilirubin cannot be converted to the direct form; it therefore remains indirect. As long as the buildup of indirect bilirubin remains in the circulatory system, the red coloring of the blood cells covers the yellow tint of the bilirubin. After the level of this indirect bilirubin has risen to more than 7 mg/100 mL, however, bilirubin permeates the tissue outside the circulatory system and causes the infant to appear jaundiced.
Observe infants who are prone to extensive bruising (large, breech, or immature babies) carefully for jaundice, because bruising leads to hemorrhage of blood into the subcutaneous tissue or skin. A cephalhematoma is a collection of blood under the periosteum of the skull bone. As the bruising in these locations heals and the red blood cells are hemolyzed, additional indirect bilirubin is released and can be another cause of jaundice (Nicholson, 2007).
If intestinal obstruction is present and stool cannot be evacuated, intestinal flora may break down bile into its basic components, leading to the release of indirect bilirubin into the bloodstream again. Early feeding of newborns promotes intestinal movement and excretion of meconium and helps prevent indirect bilirubin buildup from this source.
The level of jaundice in newborns may be judged grossly by estimating the extent to which it has progressed on the surface of the infant’s body, as it is noticed first in the head and then spreads to the rest of the body.
Treatment for physiologic jaundice or the routine rise in bilirubin in newborns is rarely necessary, except for measures such as early feeding to speed passage of feces through the intestine and prevent reabsorption of bilirubin from the bowel.
Above-normal indirect bilirubin levels are potentially dangerous because, if enough indirect bilirubin (about 20 mg/100 mL) leaves the bloodstream, it can interfere with the chemical synthesis of brain cells, resulting in permanent cell damage, a condition termed kernicterus. If this occurs, permanent neurologic damage, including cognitive challenge, may result.
There is no set level at which indirect serum bilirubin requires treatment, because other factors, such as age, maturity, and breastfeeding status, affect this determination. If the level rises to more than 10 to 12 mg/100 mL, treatment is usually considered. Phototherapy (exposure of the infant to light to initiate maturation of liver enzymes) is a common therapy. If this is necessary, the incubator and light source can be moved to the mother’s room so that the mother is not separated from her baby. Some infants need continued therapy after discharge and receive phototherapy at home (Mills & Tudehope, 2009).
Compared with formula-fed babies, a small proportion of breastfed babies may have more difficulty converting indirect bilirubin to direct bilirubin, because breast milk contains pregnanediol (a metabolite of progesterone), which depresses the action of glucuronyl transferase. However, breastfeeding alone rarely causes enough jaundice to warrant therapy (Thilo & Rosenberg, 2008).
Pallor
Pallor in newborns is usually the result of anemia. This may be caused by
(a) excessive blood loss when the cord was cut,
(b) inadequate flow of blood from the cord into the infant at birth,
(c) fetal–maternal transfusion,
(d) low iron stores caused by poor maternal nutrition during pregnancy, or
(e) blood incompatibility in which a large number of red blood cells were hemolyzed in utero. It also may be the result of internal bleeding. A baby who appears pale should be watched closely for signs of blood in stool or vomitus.
Harlequin Sign
Occasionally, because of immature circulation, a newborn who has been lying on his or her side appears red on the dependent side of the body and pale on the upper side, as if a line had been drawn down the center of the body. This is a transient phenomenon; although startling, it is of no clinical significance. The odd coloring fades immediately if the infant’s position is changed or the baby kicks or cries vigorously.
B. Birthmarks
It is important to be able to differentiate the various types of hemangiomas that occur, so that you neither give false reassurance to parents nor worry them unnecessarily about these lesions.
Hemangiomas = vascular tumors of the skin. Three types occur.
A. Nevus Flammeus - is a macular purple or dark-red lesion (sometimes called a portwine stain because of its deep color) that is present at birth. These lesions typically appear on the face, although they are often found on the thighs as well. Those above the bridge of the nose tend to fade; the others are less likely to fade. Because they are level with the skin surface (macular), they can be covered by a cosmetic preparation later in life or removed by laser therapy, although lesions may reappear after treatment (Berger, 2009).
Nevus flammeus lesions also occur as lighter, pink patches at the nape of the neck, known as stork’s beak marks or telangiectasia. These do not fade, but they are covered by the hairline and therefore are of no consequence. They occur more often in females than in males.
B. Strawberry hemangioma - refers to elevated areas formed by immature capillaries and endothelial cells. Most are present at birth in the term neonate, although they may appear up to 2 weeks after birth. Typically, they are not present in the preterm infant because of the immaturity of the epidermis. Formation is associated with the high estrogen levels of pregnancy. They may continue to enlarge from their original size up to 1 year of age. After the first year, they tend to be absorbed and shrink in size. By the time the child is 7 years old, 50% to 75% of these lesions have disappeared.
A child may be 10 years old before the absorption is complete. Application of hydrocortisone ointment may speed the disappearance of these lesions by interfering with the binding of estrogen to its receptor sites.
C. Cavernous hemangiomas - are dilated vascular spaces. They are usually raised and resemble a strawberry hemangioma in appearance. However, they do not disappear with time as do strawberry hemangiomas. Such lesions can be removed surgically. Steroids, interferon-alfa-2a, or vincristine can be used to reduce these lesions in size, although their use must be weighed in light of side effects (Edmonds, 2008). Children who have a skin lesion may have additional ones on internal organs. Blows to the abdomen, such as those from childhood games, can cause bleeding from an internal hemangioma. For this reason, children with cavernous hemangiomas usually have their hematocrit levels assessed at health maintenance visits, to evaluate for possible internal blood loss.
Mongolian spots
Mongolian spots are collections of pigment cells (melanocytes) that appear as slate-gray patches across the sacrum or buttocks and possibly on the arms and legs. They tend to occur in children of Asian, southern European, or African ethnicity (Thilo & Rosenberg, 2008). They disappear by school age without treatment. Be sure to inform parents that these are not bruises; otherwise, they may worry their baby sustained a birth injury.
C. Vernix Caseosa
Vernix caseosa is a white, cream cheese–like substance that serves as a skin lubricant in utero. Usually, it is noticeable on a term newborn’s skin, at least in the skin folds, at birth. Document the color of vernix, because it takes on the color of the amniotic fluid. For example, a yellow vernix implies that the amniotic fluid was yellow from bilirubin; green vernix indicates that meconium was present in the amniotic fluid. Until the first bath, when vernix is washed away, handle newborns with gloves to protect yourself from exposure to this body fluid. Never use harsh rubbing to wash away vernix. A newborn’s skin is tender, and breaks in the skin caused by too vigorous attempts at removal may open portals of entry for bacteria.
D. Lanugo
Lanugo is the fine, downy hair that covers a newborn’s shoulders, back, and upper arms. It may be found also on the forehead and ears. A baby born between 37 to 39 weeks of gestation has more lanugo than a newborn of 40 weeks’ gestational age. Postmature infants (more than 42 weeks of gestation) rarely have lanugo. Lanugo is rubbed away by the friction of bedding and clothes against the newborn’s skin. By 2 weeks of age, it has disappeared.
E. Desquamation
Within 24 hours after birth, the skin of most newborns has become extremely dry. The dryness is particularly evident on the palms of the hands and soles of the feet. This results in areas of peeling similar to those caused by sunburn. This is normal, however, and needs no treatment. Parents may apply hand lotion to prevent excessive dryness if they wish.
F. Milia
All newborn sebaceous glands are immature. At least one pinpoint white papule (a plugged or unopened sebaceous gland) can be found on the cheek or across the bridge of the nose of almost every newborn. Such lesions, termed milia, disappear by 2 to 4 weeks of age, as the sebaceous glands mature and drain. Teach parents to avoid scratching or squeezing the papules, to prevent secondary infections.
G. Erythema Toxicum
In most normal mature infants, a newborn rash called erythema toxicum can be observed. This usually appears in the first to fourth day of life but may appear up to 2 weeks of age. It begins with a papule, increases in severity to become erythema by the second day, and then disappears by the third day. It is sometimes called a flea-bite rash because the lesions are so minuscule. One of the chief characteristics of the rash is its lack of pattern. It occurs sporadically and unpredictably and may last hours rather than days. It is caused by a newborn’s eosinophils reacting to the environment as the immune system matures. It requires no treatment.
H. Skin Turgor
Newborn skin should feel resilient if the underlying tissue is well hydrated. If a fold of the skin is grasped between the thumb and fingers, it should feel elastic. When it is released, it should fall back to form a smooth surface. If severe dehydration is present, the skin will not smooth out again but will remain in an elevated ridge. Poor turgor is seen in newborns who suffered malnutrition in utero, who have difficulty sucking at birth, or who have certain metabolic disorders such as adrenocortical insufficiency.
2. Head
A newborn’s head appears disproportionately large because it is about one fourth of the total body length; in an adult, a head is one eighth of total height. The forehead of a newborn is large and prominent. The chin appears to be receding, and it quivers easily if an infant is startled or cries. Well-nourished newborns have full-bodied hair; poorly nourished and preterm infants have thin, lifeless hair. If internal fetal monitoring was used during labor, a newborn may exhibit a pinpoint ulcer at the point where the monitor was attached.
Fontanelles
The fontanelles are the spaces or openings where the skull bones join. The anterior fontanelle is located at the junction of the two parietal bones and the two fused frontal bones. It is diamond shaped and measures 2 to 3 cm (0.8 to 1.2 in) in width and 3 to 4 cm (1.2 to 1.6 in) in length. The posterior fontanelle is located at the junction of the parietal bones and the occipital bone. It is triangular and measures about 1 cm (0.4 in) in length.
The anterior fontanelle can be felt as a soft spot. It should not appear indented (a sign of dehydration) or bulging (a sign of increased intracranial pressure) when the infant is held upright. The fontanelle may bulge if the newborn strains to pass a stool or cries vigorously or is lying supine. With vigorous crying, a pulse may additionally be seen in the fontanelle. The anterior fontanelle normally closes at 12 to 18 months of age. In some newborns, the posterior fontanelle is so small that it cannot be palpated readily. The posterior fontanelle closes by the end of the second month.
Sutures
The skull sutures, the separating lines of the skull, may override at birth because of the extreme pressure exerted on the head during passage through the birth canal. If the sagittal suture between the parietal bones overrides, the fontanelles are less perceptible than usual. The overriding subsides in 24 to 48 hours.
Suture lines should never appear widely separated in newborns. Wide separation suggests increased intracranial pressure because of abnormal brain formation, abnormal accumulation of cerebrospinal fluid in the cranium (hydrocephalus), or an accumulation of blood from a birth injury such as subdural hemorrhage. Fused suture lines also are abnormal; they require radiographic confirmation and further evaluation, because they will prevent the head from expanding with brain growth.
Molding
The part of the infant’s head that engaged the cervix (usually the vertex) molds to fit the cervix contours during labor. After birth, this area appears prominent and asymmetric. Molding may be so extreme in the baby of a primiparous woman that the baby’s head appears as a dunce cap. The head will restore to its normal shape within a few days after birth.
Caput Succedaneum
Caput succedaneum is edema of the scalp at the presenting part of the head. It may involve wide areas of the head, or it may resemble a large egg. The edema, which crosses the suture lines, is gradually absorbed and disappears at about the third day of life. It needs no treatment (Nicholson, 2007).
Cephalhematoma
A cephalhematoma, a collection of blood between the periosteum of a skull bone and the bone itself, is caused by rupture of a periosteal capillary because of the pressure of birth. Swelling usually appears 24 hours after birth. Although the blood loss is negligible, the swelling is usually severe and is well outlined as an egg shape. It may be discolored (black and blue) because of the presence of coagulated blood.
A cephalhematoma is confined to an individual bone, so the associated swelling stops at the bone’s suture line. It often takes weeks for a cephalhematoma to be absorbed. It might be supposed that the blood could be aspirated to relieve the condition. However, such a procedure would introduce the risk of infection and is unnecessary, because the condition will subside by itself. As the blood captured in the space is broken down, a great amount of indirect bilirubin may be released, leading to jaundice.
Craniotabes
Craniotabes is a localized softening of the cranial bones that is probably caused by pressure of the fetal skull against the mother’s pelvic bone in utero. It is more common in firstborn infants than in infants born later, because of the lower position of the fetal
head in the pelvis during the last 2 weeks of pregnancy in primiparous women. With craniotabes, the skull is so soft that the pressure of an examining finger can indent it. The bone returns to its normal contour after the pressure is removed. The condition corrects itself without treatment after a few months, as the infant takes in calcium in milk.
3. Eyes
Newborns usually cry tearlessly, because their lacrimal ducts do not fully mature until about 3 months of age. Almost without exception, the irises of the eyes of newborns are gray or blue; the sclera may be blue because of its thinness. Infant eyes assume their permanent color between 3 and 12 months of age. To inspect the eyes, lay the newborn in a supine position and lift the head. This maneuver causes the baby to open the eyes. A newborn’s eyes should appear clear, without redness or purulent discharge.
4. Ears
A newborn’s external ear is not as completely formed as it will be eventually, so the pinna tends to bend easily. In the term newborn, however, the pinna should be strong enough to recoil after bending. The level of the top part of the external ear should be on a line drawn from the inner canthus to the outer canthus of the eye and back across the side of the head. Ears that are set lower than this are found in infants with certain chromosomal abnormalities, particularly trisomy 18 and 13, syndromes in which low-set ears and other physical defects are coupled with varying degrees of cognitive challenge.
A good practice is to test a newborn’s hearing by ringing a bell held about 6 inches from each ear. A hearing infant who is crying will stop momentarily at the sound. If quiet, a newborn who can hear will blink the eyes, appear to attend to the sound, and possibly startle. Although this method of testing is not highly accurate, a negative response (lack of response) is unusual.
5. Nose
A newborn’s nose tends to appear large for the face. As the infant grows, the rest of the face grows more than the nose does, and this discrepancy disappears. Test for choanal atresia (blockage at the rear of the nose) by closing the newborn’s mouth and compressing one naris at a time with your fingers. Note any discomfort or distress while breathing this way. Nasal flaring upon inspiration is another indication of respiratory distress and should be further evaluated. Also record any evidence of milia on the nose.
6. Mouth
A newborn’s mouth should open evenly when he or she cries. If one side of the mouth moves more than the other, cranial nerve injury is suggested. A newborn’s tongue appears large and prominent in the mouth. Because the tongue is short, the frenulum membrane is attached close to the tip of the tongue, creating the impression that the infant is “tongue tied.”
Inspect the palate of a newborn to be sure it is intact. Occasionally, one or two small, round, glistening, well circumscribed cysts (Epstein’s pearls) are present on the palate, a result of extra calcium that was deposited in utero. Be sure to inform parents that these pearl-like cysts are insignificant, require no treatment, and will disappear spontaneously within 1 week. Otherwise, a parent may mistake them for thrush, a Candida infection, which usually appears on the tongue and sides of the cheeks as white or gray patches and needs therapy with an antifungal drug (Subramanian et al., 2008).
7. Neck
The neck of a newborn is short and often chubby, with creased skin folds. The head should rotate freely on it. If there is rigidity of the neck, congenital torticollis, caused by injury to the sternocleidomastoid muscle during birth, might be present. In newborns whose membranes were ruptured more than 24 hours before birth, nuchal rigidity suggests meningitis.
The neck of a newborn is not strong enough to support the total weight of the head but in a sitting position, a newborn should make a momentary effort at head control. When lying prone, newborns can raise the head slightly, usually enough to lift the nose out of mucus or spit-up formula. If they are pulled into a sitting position from a supine position, the head will lag behind considerably.
8. Chest
The chest in some newborns looks small because the head is large in proportion. It is actually approximately 2 inches smaller in circumference than and as wide in the anteroposterior diameter as it is across. Not until a child is 2 years of age does the chest measurement exceed that of the head. The clavicles should be straight. A crepitus or actual separation on one or the other clavicle may indicate that a fracture occurred during birth and calcium is now being deposited at that point.
Overall, a newborn’s chest should appear symmetric side to side. Respirations are normally rapid (30 to 60 breaths per minute) but not distressed. A supernumerary nipple (usually found below and in line with the normal nipples) may be present. If so, it may be removed later for cosmetic purposes although this is not necessary.
In both female and male infants, the breasts may be engorged. Occasionally, the breasts of newborn babies secrete a thin, watery fluid popularly termed witch’s milk. Engorgement develops in utero as a result of the influence of the mother’s hormones. As soon as the hormones are cleared from the infant’s system (about 1 week), the engorgement and any fluid that is present subside.
Retraction (drawing in of the chest wall with inspiration) should not be present. An infant with retractions is using such strong force to pull air into the respiratory tract that he or she is pulling in the anterior chest muscle. An abnormal sound, such as grunting, suggests respiratory distress syndrome; a high, crowing sound on inspiration suggests stridor or immature tracheal development.
9. Abdomen
The contour of a newborn abdomen looks slightly protuberant. A scaphoid or sunken appearance may indicate missing abdominal contents or a diaphragmatic hernia (bowel positioned in the chest instead of the abdomen). Bowel sounds should be present within 1 hour after birth. The edge of the liver is usually palpable 1 to 2 cm below the right costal margin. The edge of the spleen may be palpable 1 to 2 cm below the left costal margin. Tenderness is difficult to determine in a newborn. If it is extreme, however, palpation will cause the infant to cry, thrash about, or tense the abdominal muscles to protect the abdomen.
For the first hour after birth, the stump of the umbilical cord appears as a white, gelatinous structure marked with the blue and red streaks of the umbilical vein and arteries. When the cord is first cut, the vessels are counted to be certain that one vein and two arteries are present.
Inspect the cord clamp to be certain it is secure. After the first hour of life, the cord begins to dry and shrink, and it turns brown like the dead end of a vine. By the second or third day, it has turned black. It breaks free by day 6 to 10, leaving a granulating area a few centimeters wide that heals during the following week.
The base of the cord should appear dry. A moist or odorous cord suggests infection. If present, infection should receive immediate treatment or it may enter a newborn’s bloodstream and cause septicemia.
To finish the abdominal assessment, elicit an abdominal reflex. Stroking each quadrant of the abdomen will cause the umbilicus to move or “wink” in that direction. This superficial abdominal reflex is a test of spinal nerves T8–T10. The reflex may not be demonstrable in newborns until the 10th day of life.
10. Anogenital
Area Inspect the anus of a newborn to be certain it is present, patent, and not covered by a membrane (imperforate anus). Test for anal patency by gently inserting the tip of your gloved and lubricated little finger. Also note the time after birth at which the infant first passes meconium. If a newborn does not do so in the first 24 hours, suspect imperforate anus or meconium ileus.
Male Genitalia
The scrotum in most male newborns is edematous and has rugae (folds in the skin). It may be deeply pigmented in African American or dark-skinned newborns. Make a practice of pressing your nondominant hand against the inguinal ring before palpating for testes, so they do not slip upward and out of the scrotal sac as you palpate.
Both testes should be present in the scrotum. If one or both testicles are not present (cryptorchidism), referral is needed to establish the extent of the problem. This condition could be caused by agenesis (absence of an organ), ectopic testes (the testes cannot enter the scrotum because the opening to the scrotal sac is closed), or undescended testes (the vas deferens or artery is too short to allow the testes to descend).
Elicit a cremasteric reflex by stroking the internal side of the thigh. As the skin is stroked, the testis on that side moves perceptibly upward. This is a test for the integrity of spinal nerves T8–T10. The response may be absent in newborns who are younger than 10 days. The penis of newborns appears small, approximately 2 cm long. If it is less than this, the newborn should be referred for evaluation by an endocrinologist. Inspect the tip of the penis to see that the urethral opening is at the tip of the glans, not on the dorsal surface (epispadias) or on the ventral surface (hypospadias).
Female Genitalia
The vulva in female newborns may be swollen because of the effect of maternal hormones. Some female newborns have a mucus vaginal secretion, which is sometimes blood-tinged
(pseudomenstruation). Again, this is caused by the action of maternal hormones. The discharge disappears as soon as the infant’s system has cleared the hormones. The discharge should not be mistaken for an infection or taken as an indication that trauma has occurred.
11. Back
The spine of a newborn typically appears flat in the lumbar and sacral areas. The curves seen in an adult appear only after a child is able to sit and walk. Inspect the base of a newborn’s spine carefully to be sure there is no pinpoint opening, dimpling, or sinus tract in the skin, which would. suggest a dermal sinus or spinal bifida occulta. True neural tube defects in newborns are greatly decreased in incidence because of the recognition that lack of folic acid during pregnancy leads to these (De Wals et al., 2007).
A newborn normally assumes the position maintained in utero, with the back rounded and the arms and legs flexed on the abdomen and chest. A child who was born in a frank breech position tends to straighten the legs at the knee and bring their feet up next to the face.
12. Extremities
The arms and legs of a newborn appear short. The hands are plump and clenched into fists. Newborn fingernails are soft and smooth, and usually long enough to extend over the fingertips. Test the upper extremities for muscle tone by unflexing the arms for approximately 5 seconds. If tone is good, an arm should return immediately to its flexed position after being released. Hold the arms down by the sides and note their length. The fingertips should reach the proximal thigh.
Unusually short arms may signify achondroplastic dwarfism. Observe for unusual curvature of the little finger, and inspect the palm for a simian crease (a single palmar crease, in contrast to the three creases normally seen in a palm). Although curved fingers and simian creases can occur normally, they are commonly associated with Down syndrome (Elias, ChunHui, & Manchester, 2008).
Assess for webbing (syndactyly), extra toes or fingers (polydactyly), or unusual spacing of toes, particularly between the big toes and the others (this finding is present in certain chromosomal disorders, although it is also a normal finding in some families). Test to see whether the toenails fill immediately after blanching from pressure. Normally, newborn legs are bowed as well as short. The sole of the foot appears flat because of an extra pad of fat in the longitudinal arch. The foot of a term newborn has many crisscrossed lines on the sole, covering approximately twothirds of the foot. If these creases cover less than two-thirds of the foot or are absent, suspect immaturity.
With a newborn in a supine position, both hips can be flexed and abducted to such an extent (180 degrees) that the knees touch or nearly touch the surface of the bed. If the hip joint seems to lock short of this distance (160 to 170 degrees), hip subluxation (a shallow and poorly formed acetabulum) is suggested (McCarthy & MacEwen, 2007).
A further test for subluxation can be elicited by holding the infant’s leg with the fingers on the greater and lesser trochanter and then abducting the hip; if subluxation is present, a “clunk” of the femur head striking the shallow acetabulum can be heard
(Ortolani’s sign). If the hip can be felt to actually slip in the socket, this is Barlow’s sign. Subluxated hip may be bilateral but is usually unilateral. It is important that hip subluxation be discovered as early as possible, because correction is most successful if it is initiated early.