First Aid for the Pediatrics Clerkship, 3 Ed.

Gestation and Birth

 

EMBRYOLOGY

Gestational/Embryologic Landmarks

See Table 2-1.


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The main source of energy for a growing fetus is carbohydrates.


Germ Layers

See Table 2-2.

Heart

Image Week 3: Paired heart tubes begin to work.

Image Week 4:

Image Primordial atrium is divided into left and right by septa primum and secundum.

Image Septum primum forms the valve of the foramen ovale, which closes about 3 months after birth.

Image Failure of the foramen ovale to close results in an atrial septal defect (ASD).

Image Week 7:

Image The single ventricle is divided into left and right; prior to that the interventricular foramen communicates between left and right sides.

Image Failure of the interventricular foramen to close results in a ventricular septal defect (VSD).


Image

Bicuspid aortic valve and VSD are the most common congenital heart defects.


TABLE 2-1. Gestational/Embryologic Landmarks

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TABLE 2-2. Summary of Germ Layer Derivatives

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Image

Upper portion of fetal body is perfused much better than lower because of the way fetal circulation functions.


Circulation

Image See Figure 2-1.

Image Well-oxygenated blood returns from placenta through umbilical vein, where half of it enters the inferior vena cava through the ductus venosus (continuation of the umbilical vein beyond the branching of the left and right portal veins), and the rest enters the hepatic circulation (preferentially through the left portal vein).

Image

FIGURE 2-1. Fetal circulation.

Image Despite the fact that the umbilical venous blood joins the inferior vena cava prior to entering the right atrium, the streams do not mix substantially. Blood from the artery to vein is preferentially shunted through the foramen ovale to the left atrium, while blood from the lower inferior vena cava, right hepatic circulation, and superior vena cava enters the right ventricle.

Image The major portion of blood exiting the right ventricle is then shunted to the aorta through the ductus arteriosus because the lungs are collapsed and pulmonary artery pressures are high.

Image Sixty-five percent of blood in the descending aorta returns to the umbilical arteries for reoxygenation at the placenta; the remainder supplies the inferior part of the body.

Image After birth, pulmonary artery pressure drops because the lungs expand, reducing flow across the ductus arteriosus and stimulating its closure (usually within first few days of life). (See Figure 2-2.)

Image Pressure in the left atrium becomes higher than that in the right atrium after birth due to the ↑ pulmonary return, which stimulates closure of the foramen ovale (usually complete by third month of life).


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Closure of the ductus arteriosus can be prevented by prostaglandin E1 and facilitated by indomethacin (via inhibition of prostaglandin synthesis).



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Failure of kidneys to develop can → oligohydramnios (↓ fluid in the amniotic cavity).


Hemoglobin

Fetal erythropoiesis occurs in the yolk sac (3–8 weeks), liver (6–8 weeks), spleen (9–28 weeks), and then bone marrow (28 weeks onward).


Image

Failure of kidneys to migrate can → ectopic kidneys.


Genitourinary Tract

Image Metanephri (permanent kidneys) start functioning at 9 weeks; urine is excreted into amniotic cavity.

Image Initially, kidneys lie in the pelvis; by 8 weeks they migrate into their adult position.

Image Morphologic sexual characteristics do not develop until 7 weeks’ gestation.

Image In males, testis-determining factor induces primary sex cords to develop as male gonads, with testosterone production by 8 weeks.

Image Testicles develop intra-abdominally and then descend through inguinal canals into the scrotum by 26 weeks.

Image Ovaries are identified by 10 weeks; primary sex cords develop into female gonads with primordial follicles developing prenatally.


Image

A horseshoe kidney gets caught on the inferior mesenteric artery (IMA) during ascent.



Image

Failure of testicle(s) to descend, cryptorchidism, may need to be corrected surgically to prevent progressive dysplasia and may affect fertility.


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FIGURE 2-2. Mechanism of ductus arteriosus patency/closure.

Gastrointestinal Tract

Image By 10 weeks, the midgut returns from the umbilical cord, where it was developing, to the abdominal cavity, while undergoing counterclockwise rotation.

Image Insufficient rotation of the midgut, called malrotation, can present in neonatal period as intestinal obstruction.

Image Incomplete separation of foregut and primitive airway can → tracheoesophageal fistula (TEF).

Image Failure of the intestine to return to the abdominal cavity with intestinal contents remaining at the base of the umbilical cord causes gastroschisis, a full-thickness abdominal wall defect with extruded intestine.


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Infants born prior to 30 weeks are given exogenous surfactant to prevent respiratory distress syndrome (RDS). Mom is given steroids.


Lungs

By 24 weeks, primitive alveoli are formed and surfactant production is begun.

Central Nervous System (CNS)

Image During week 3, the neural tube is formed on the ectodermal surface.

Image Neural tube openings (rostral and caudal) are closed by 25–27 days.

Image By week 5, subdivisions of forebrain, midbrain, and hindbrain are formed.

Image Failure of caudal neural tube to close completely can result in spina bifida (unfused vertebral arch with or without unfused dura mater and spinal cord), commonly seen in the lumbar area. Failure of the rostral neural tube to close can result in anencephaly.


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Lecithin-to-sphingomyelin ratio in the amniotic fluid greater than 3 indicates fetal lung maturity.


PLACENTA

Development

Image Fetal portion of placenta is formed from chorionic sac.

Image Maternal portion is derived from endometrium.


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Folic acid supplements during pregnancy reduce incidence of neural tube defects.


Transport

Image Nutrients, electrolytes, water, and gases are diffused or transported across the placenta.

Image Most drugs pass through placenta and can be detected in fetal plasma (eg, warfarin, morphine, propylthiouracil, and drugs of abuse).

Image A few substances cannot pass because of their size or charge (eg, heparin); protein hormones (eg, insulin) do not cross placenta.


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Maternal α-fetoprotein (AFP) is high in:

Image Multiple gestations (most common)

Image Fetal neural tube defects

Image Gastroschisis


Metabolism

Placenta synthesizes glycogen and cholesterol.

Endocrine Function

Placenta produces β-human chorionic gonadotropin (β-hCG), human chorionic adrenocorticotropic hormone (ACTH), human placental lactogen, and human chorionic somatomammotropin.


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Testing urine for β-hCG allows early detection of pregnancy.


PRENATAL DISTURBANCES

Infections

Infants who have experienced an intrauterine infection have a higher-than-average incidence of being small for gestational age, hepatosplenomegaly, congenital defects, microcephaly, and intracranial calcifications.


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Maternal AFP is low in trisomies 21 (Down’s) and 18.


TOXOPLASMOSIS

Image Maternal infection is due to ingestion of oocysts from feces of infected cats and is asymptomatic.

Image Clinical features in infants include microcephaly, hydrocephalus, intracranial calcifications, chorioretinitis, and seizures.


Image

Incorrect dates is the most common cause for abnormal AFP.


RUBELLA

Image Congenital rubella syndrome is rare due to the effectiveness of the rubella vaccine.

Image Maternal infection early in pregnancy can result in congenital rubella syndrome, which includes meningoencephalitis, microcephaly, cataracts, sensorineural hearing loss, and congenital heart disease (patent ductus arteriosus and pulmonary artery stenosis).


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Among women infected with toxoplasmosis, only 50% will give birth to an infected neonate.


CYTOMEGALOVIRUS (CMV)

Image Common—occurs in 1% of newborns.

Image Newborn disease is associated with primary maternal infection with a 50% chance of infection.

Image In those affected, only 5% have neurologic deficits.

Image Infection occurs in 1% of pregnancies with recurrent or reactivated infection.

Image CMV transmitted intrapartum, through infected blood or through breast milk, is not associated with neurologic deficits.

Image Clinical features include intrauterine growth retardation (IUGR), low birth weight, petechiae and purpura, jaundice and hepatosplenomegaly, microcephaly, chorioretinitis, and intracranial calcifications.

Image Late manifestations like learning and hearing deficits can occur in 10% of clinically inapparent infections.


Image

Pregnant women should not change a cat’s litter box, due to risk of toxoplasmosis.


Toxins and Teratogens

ALCOHOL

Image Most common teratogen.

Image The amount of alcohol consumed correlates with the severity of spectrum of effects in the neonate, ranging from mild reduction in cerebral function to classic fetal alcohol syndrome (see Figure 2-3).


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Incidence of fetal alcohol syndrome is higher in the Native American population because of the higher incidence of alcoholism.


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FIGURE 2-3. Fetal alcohol syndrome.

Notice the depressed nasal bridge, flat philtrum, long upper lip, and thin vermillion border. (Reproduced, with permission, from Stoler JM, Holmes LB. Underrecognition of prenatal alcohol effects in infants of known alcohol abusing women. Journal of Pediatrics 135(4):430–436, 1999.)

Image Clinical manifestations include microcephaly and mental retardation, IUGR, facial dysmorphism (midfacial hypoplasia, micrognathia, shortened nasal philtrum, short palpebral fissures, and a thin vermillion border), renal and cardiac defects, and hypospadias.

COCAINE

Image

Term, 5-lb., 2-day-old infant has irritability, nasal stuffiness, and coarse tremors. He feeds poorly and has diarrhea. Think: Cocaine or heroin withdrawal.

Cocaine readily crosses the placental barrier, placing the fetus at risk. Symptoms of cocaine withdrawal include tremors, high-pitched cry, irritability, excess suck, apnea, and tachycardia, which can become evident within the first 72 hours of life. Opiates also cross the placenta. Tremor and irritability are the common symptoms of opiate withdrawal. Vague autonomic symptoms such as yawning and sneezing are often present.

Image Causes maternal hypertension and constriction of placental circulation →↓ uterine blood flow and fetal hypoxia.

Image Associated with a higher risk of spontaneous abortion, placental abruption, fetal distress, meconium staining, preterm birth, IUGR, and low Apgar scores at birth.

Image Associated with intracranial hemorrhage and necrotizing enterocolitis; cardiac, skull, and genitourinary malformations; and ↑ incidence of sudden infant death syndrome (SIDS).

Image Cocaine withdrawal in an infant causes irritability, ↑ tremulousness, and poor feeding, as well as ↑ incidence of learning difficulties and attention and concentration deficits later on.


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Cocaine use is associated with placental abruption.


NARCOTICS

Heroin and methadone are associated with IUGR, SIDS, and infant narcotic withdrawal syndrome.


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Infants of narcotic-abusing mothers should never be given naloxone in the delivery room because it may precipitate seizures.


TOBACCO

Smoking is associated with ↓ birth weight.

PHENYTOIN

Phenytoin is associated with fetal hydantoin syndrome, which includes IUGR, mental retardation, dysmorphic facies, and hypoplasia of nails and distal phalanges.

TETRACYCLINE

Tetracycline causes tooth discoloration and inhibits bone formation.

ISOTRETINOIN (ACCUTANE)

Accutane is associated with hydrocephalus, microtia, micrognathia, and aortic arch abnormalities.

WARFARIN

Image Warfarin causes abnormal cartilage development, mental retardation, deafness, and blindness.

Image Warfarin is no longer used in pregnant women due to the advent of low-molecular-weight heparin, which has fewer side effects and is well tolerated.

MATERNAL CONDITIONS

Diabetes

Image Associated with macrosomia (weight > 4 kg), which can → birth-related injury.

Image Fetal complications are related to degree of control of maternal diabetes.

Image Other fetal/neonatal complications include metabolic disorders (hypoglycemia, hypocalcemia, and hypomagnesemia), perinatal asphyxia, respiratory distress syndrome, hyperbilirubinemia, polycythemia and hyperviscosity, and congenital malformations including cardiac, renal, gastrointestinal, neurologic, and skeletal defects.


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Elevation of maternal glucose causes elevated fetal glucose, → fetal hyperinsulinism, which can → hypoglycemia in the newborn.


Others

Image Hypertension and renal and cardiac disease are associated with small-for-gestational-age babies and prematurity.

Image Maternal lupus is related to first-degree atrioventricular (AV) block in affected infants.


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Vascular disease of placenta, caused by maternal illness (such as diabetes or lupus) can → insufficient supply of nutrients to fetus and IUGR.


DELIVERY ROOM

Delivery Room Care

Image Once the head is delivered, the nose and mouth are suctioned.

Image Once the whole body is delivered, the newborn is held at the level of the table and the umbilical cord is clamped.

Image Newborn is then placed under radiant warmer and is dried with warm towels.

Image Mouth and nose are gently suctioned.

Image Gentle rubbing of the back or flicking of the soles of the feet, if needed to stimulate breathing.

Image When the umbilical cord is clamped and cut, absent blood flow within the umbilical vein → the closure of the ductus venosus.

Apgar Scoring

Image Practical method of assessing newborn infants immediately after birth to help identify those requiring resuscitation on a scale of 0–10. It is not a substitute for assessing the ABCs in neonatal resuscitation.

Image Assessment at 1 and 5 minutes; further assessments at 10 and 15 minutes may indicate success of resuscitation (see Table 2-3). Resuscitation efforts should not be delayed or interrupted to assign an Apgar score.

Image A poor Apgar score alone cannot be used to diagnose asphyxia or predict the development of cerebral palsy.

Prophylaxis

Image Gonococcal and chlamydial eye infection prophylaxis is with erythromycin or tetracycline ointment.

Image Vitamin K is given intramuscularly (IM) to prevent hemorrhagic disease of the newborn.

Cord Blood/Stem Cells

Image Blood gas study should be sent if fetal distress is present.

Image Can be used to test for infant’s blood type.

Image Rich in stem cells, which are pleuripotential cells that have potential use in malignancies and gene therapy.

TABLE 2-3. Apgar Scoring

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Total out of 10: 7–10 normal newborn; 4–7 may require some resuscitative measures; ≤ 3 require immediate resuscitation.

NURSERY EXAM

General Appearance

Plethora (high hematocrit secondary to chronic fetal hypoxia), jaundice, sepsis and TORCH infections, cyanosis (with congenital heart and lung disease), pallor (anemia, shock, patent ductus arteriosus).


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Prenatal infections that most commonly cause birth defects:

TORCH

Toxoplasmosis

Other (hepatitis B, syphilis, varicella-zoster virus)

Rubella

Cytomegalovirus

Herpes simplex virus/human immunodeficiency virus (HSV/HIV)

See Figure 2-4.


Skin

Image Erythema toxicum is a pustular rash distributed over the trunk, face, and extremities, which resolves over a week.

Image Mongolian spots are bluish spots present over the buttocks and back that are seen in infants of African, Asian, and Native American descent that tend to fade over a year.

Image Capillary hemangiomas (“stork bites”) are pink spots over the eyelids, forehead, and back of the neck that tend to fade with time.

Image See Dermatologic Disease chapter.

Head

Image Anterior fontanelle closes at 9–12 months.

Image Large fontanelle is seen in hypothyroidism, osteogenesis imperfecta, and some chromosomal abnormalities.

Image Absent anterior fontanel is associated with craniosynostosis.


Image

A bulging fontanelle is seen with ↑ intracranial pressure, hydrocephalus, and meningitis.


Face

Image Mouth—look for cleft lip/palate and macroglossia (large tongue is seen with hypothyroidism, Down’s, and Beckwith-Wiedemann syndrome).

Image Coarse facial features are associated with mucopolysaccharidoses.

Image Look for dysmorphic features, including micrognathia, bossing of the forehead, hypertelorism (widely spaced eyes), and low-set ears (Down’s) (see Congenital Malformations and Chromosomal Abnormalities chapter).

Eyes

Image Check for red reflex with ophthalmoscope. An absent red reflex in one or both eyes signifies blockage of the passageway between the cornea and retina such as associated with cataracts or eye tumor (retinoblastoma).

Image Look for cataracts, Brushfield spots (salt-and-pepper speckling of the iris seen in Down syndrome), leukocoria (white pupil) with retinoblastoma (rare), and subconjunctival hemorrhage, which can occur after a traumatic delivery.

Image See Special Organs—Eye, Ear, Nose chapter.

Neck

Image Inspect for thyroid enlargement and palpate along the sternocleidomastoid for hematoma.

Image Check for any fistula or tracts, which are associated with branchial closure malformations.

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FIGURE 2-4. Head CT consistent with TORCH infection–marked ventricular dilation, extensive encephalomalacia involving both cerebral hemispheres, absent corpus callosum, periventricular calcifications, skull deformity with overriding sutures.

Chest

Image Symmetry/equality of breath sounds.

Image Retractions and grunting may signify respiratory distress (nasal flaring, intercostal retractions, use of accessory muscles).

Image Breasts may be enlarged from the effects of maternal estrogens.

Cardiovascular

Image Heart rate rhythm, quality of heart sounds, and the presence of a murmur. Murmur in a newborn infant can be due to open ductus arteriosus, but persistent murmur is always pathologic and needs evaluation.

Image Check pulses and compare brachial with femoral pulse to get an estimate of vascular volume and also to rule out aortic arch obstruction (aortic stenosis, coarctation of aorta), where the femoral pulses will be weak or absent.

Abdomen

Image Palpate for masses.

Image Examine umbilicus for omphalocele and gastroschisis.

Image Inspect the umbilical cord for single umbilical artery (normally two); if present, may indicate congenital anomalies.

Extremities

Image Check both clavicles for any step off especially in the midclavicular area, where most clavicles fractures occur.

Image Primitive reflexes (see Growth and Development chapter).

Image Examine for congenital hip dysplasia.


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Acrocyanosis (blue hands and feet only) can be normal in a newborn.


Back

Look for dimples or tufts of hair that may indicate spina bifida.


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Papilledema does not occur in infants with open cranial sutures.


Genitalia

Image Girls may have vaginal bleeding and swollen labia secondary to withdrawal of maternal estrogens.

Image In boys, palpate for the presence of testicles in scrotum and look for hypo- or epispadias (urethral opening proximal to normal position either on the dorsal or ventral surface).

SMALL OR LARGE FOR GESTATIONAL AGE

Small for Gestational Age (SGA)

Image Birth weight less than the tenth percentile for gestational age.

Image There are two broad categories, early and late onset.

Image Early onset:

Image Insult that begins before 28 weeks’ gestational age.

Image Head circumference and height are proportionally small-sized (symmetric).

Image Seen in infants born to mothers with severe vascular disease with hypertension, renal diseases, congenital anomalies, infections, and chromosomal abnormalities.

Image Late onset or asymmetric IUGR.

Image Occurs with an insult after 28 weeks’ gestational age.

Image Sparing of the head circumference.

Image Can occur with multiple gestation and preeclampsia.


Image

Absent breath sounds may signify a tension pneumothorax or atelectasis; bowel sounds in the thorax may indicate congenital diaphragmatic hernia.


Large for Gestational Age (LGA)

Image Birth weight greater than the 90th percentile for gestational age.

Image Those at risk are infants of diabetic mothers, postmature infants, and those with Beckwith-Wiedemann syndrome.

Image Most LGA infants have large parents and are constitutionally large.

Image Macrosomic infants are those with a birth weight > 4 kg.


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Diminished femoral pulses are seen in coarctation of the aorta.


BIRTH TRAUMA

Clavicular Fracture

Image Most common bone fracture during delivery.

Image Complete fracture symptoms involve ↓ or absent movement, gross deformity of clavicle, tenderness on palpation, and localized crepitus.

Image Greenstick (partial) fractures have no symptoms and the diagnosis is made at 7–10 days because of callus formation.

Image Management is often conservative (pin arm inside sleeve to shirt to ↓ movement).


Image

The most common cause of an abdominal mass in a newborn is an enlarged kidney.


Caput Succedaneum

Image Area of edema over the presenting portion of the scalp during a vertex delivery.

Image Associated with bruising and petechiae.

Image Can cross suture lines.


Image

Layers of the skull can be remebered by this mnemonic:

SCALP

Skin

Cutaneous tissue

Aponeurosis

Loose areolar tissue

Periosteum


Cephalohematoma

Image Caused by bleeding that occurs below the periosteum of the overlying bone (usually the parietal).

Image Associated with skull fractures in 5–10%, most often linear.

Image Contained within the periosteum: does not cross suture lines.

Image Subgaleal bleed:

Image Usually associated with delivery trauma or a bleeding disorder.

Image Always between the aponeurosis and periosteum layers, with bleeding into the loose areolar tissue.

Image Crosses suture lines and feels very boggy with localization to the dependent area.

Image Risk factor for significant indirect hyperbilirubinemia in the infant.


Image

Circumcision should be avoided in boys with hypo- or epispadias, as foreskin can be used to repair these defects later on.


Skull Fracture/Epidural Hematoma

Image Skull fractures are uncommon; most are linear and associated with cephalohematoma. Depressed fractures are often visible and may require surgery.

Image Epidural hematomas are rare and may require prompt surgical evacuation.


Image

All macrosomic infants should be examined for signs of birth trauma and checked for hypoglycemia.


Molding

Image Temporary asymmetry of the skull from the overlapping of bones that occurs following prolonged labor and vaginal deliveries.

Image Normal head shape is regained within a week.


Image

Complete clavicular fractures will → absence of Moro’s reflex.


Klumpke’s Palsy

Image Involves the lower arm and affects the seventh and eighth cervical and first thoracic nerve roots. The hand is paralyzed and has an absent grasp reflex, causing a “claw hand” deformity.

Image It is rare to have an isolated Klumpke’s palsy.

Image Is often accompanied by Horner syndrome.


Image

Caput succedaneum is external to the periosteum and crosses the midline of the skull and suture lines versus a cephalohematoma, which is below the periosteum and does not cross suture lines.


Erb’s Palsy

Image Erb-Duchenne involves the upper arm and is the most common type.

Image Involves the fifth and sixth cervical roots, and the arm is adducted and internally rotated, but the grasp reflex is intact (see Figure 2-5).


Image

Brachial plexus injuries can occur during birth when traction is used with shoulder dystocia.


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FIGURE 2-5. Erb’s palsy

PERINATAL INFECTIONS

Risk Factors

Image Rupture of amniotic membranes for 18 hours or more.

Image Chorioamnionitis.

Image Intrapartum maternal fever.

Image Maternal group B Streptococcus (GBS) colonization.

Image Prematurity.

Image Maternal UTI with gram-negative organisms is emerging as the common cause due to perinatal GBS prophylaxis.


Image

Degree of functional return in birth brachial plexus injuries depends on the severity of the nerve injury (stretch, rupture, avulsion).


Group B Streptococcus (GBS)

Image Major cause of severe systemic infection in neonates.

Image Vertical transmission most important route of transmission.

Image Two patterns of disease:

Image Early-onset disease (< 1 week of age):

Image Presents shortly after birth (usually < 12 hours) as sepsis, pneumonia, or meningitis.

Image Infants < 24 hours of age may not have fever.

Image Can be associated with persistent pulmonary hypertension of the newborn (PPHN).

Image Late-onset disease (1 week–3 months): Occurs after the first week of life and most often manifests as bacteremia without a source. The most common focal infection is meningitis (35%) and presents with bulging fontanelle, lethargy, irritability, vomiting, and seizures.

Image Diagnosis is confirmed by GBS isolation from sterile body fluid (blood, cerebrospinal fluid).

Image Empiric therapy with ampicillin and gentamicin should be started only if infant is symptomatic (ie, apnea, low temperature, feeding intolerance).

Image If infant is asymptomatic, monitoring for 48 hours is sufficient since infant will typically show signs of infection within a 48-hour period.

Image Intrapartum therapy with penicillin G does not prevent late onset disease but protects against early onset disease.


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Twenty percent of pregnant women are colonized with GBS. It is recommended that all pregnant women be screened (vaginal, rectal swabs) at 35–37 weeks of gestation, and be given intrapartum antibiotics if positive.


Escherichia coli

Image Principal cause of gram-negative sepsis and meningitis in newborn.

Image Commonly colonize genitourinary (GU) and gastrointestinal (GI) tracts.

Image Risk factors include maternal urinary tract infection (UTI) during last month of pregnancy in addition to previously mentioned risk factors.

Image Clinical manifestations include sepsis, meningitis, UTI, pneumonia.

Image Diagnosis is confirmed by E coli isolation from normally sterile body fluids.

Image Treatment should be based on antibiotic sensitivity data, but a third-generation cephalosporin should be used as an empiric agent.

Image E. coli infection in the infant is common in infants with galactosemia.

Listeria monocytogenes

Image Important cause of neonatal sepsis.

Image Colonizes GU tract.

Image Clinical manifestations include sepsis and meningitis.

Image Diagnosis is confirmed by L monocytogenes isolation from sterile body fluid.

Image Treatment is with penicillin or ampicillin.

Herpes Simplex

Image Prevalence rate for adults with genital herpes is about 20%.

Image Risk of neonatal disease is much higher with primary maternal infection (44%), and only 3% for a recurrent one.

Image Ninety percent of neonatal infection is acquired through infected secretions during birth.

Image There are three distinct patterns of disease:

Image Cutaneous disease:

Image Involves skin, mouth, and eyes.

Image Vesicular eruptions appear around 7–10 days of life, usually on presenting part.

Image If not recognized promptly, can progress to disseminated disease.

Image Encephalitic disease:

Image Occurs at second to third week of life.

Image Clinical signs include lethargy, irritability, poor suck, seizures.

Image Cutaneous lesions may be absent.

Image Disseminated disease:

Image Sepsis-like clinical picture (apnea, irritability, hypotonia, hypotension).

Image Cutaneous lesions may be absent.


Image

Cesarean section is performed for women with primary genital herpes and vaginal lesions in late gestation.


DIAGNOSIS

Image HSV can be isolated in cell culture from skin lesions or nasopharyngeal swabs.

Image Polymerase chain reaction (PCR) is a sensitive tool for HSV detection.

TREATMENT

Image Acyclovir is very effective in treatment of HSV infection.

Image Course of treatment is often prolonged (21 days) for encephalitic and disseminated forms.

Chlamydia

Image

A 3-week-old infant presents with paroxysmal cough and tachypnea, but no fever; bilateral diffuse crackles, hyperinflation, and patchy infiltrates on x-ray; he had conjunctivitis at 10 days of age. Think: Chlamydia trachomatis.

The incubation period of chlamydial conjunctivitis is between 5 and 14 days; usually manifests later than gonococcal conjunctivitis (occurs 2–5 days after birth). It is commonly acquired from the birth canal during delivery. It is the most common infectious cause of conjunctivitis in the neonates. Generally, gonococcal conjunctivitis usually has a more rapid and progressive course than Chlamydia.

Image Acquired during passage through the birth canal of an infected mother.

Image Causes conjunctivitis (few days to several days) and pneumonia (between 3 and 19 weeks).

Image Characteristic “staccato” cough may not be evident in newborn infants, and may present with frequent apneic episodes.

DIAGNOSIS

Culture.


Image

Erythromycin use has been associated with development of pyloric stenosis.


TREATMENT

Erythromycin orally for 14 days.

Syphilis

Image Results from transplacental transfer of Treponema pallidum.

Image Common features include intermittent fever, osteitis and osteochondritis, hepatosplenomegaly, lymphadenopathy, persistent rhinitis (“snuffles”), and a maculopapular rash involving the palms and the soles.

Image Late manifestations include a saddle nose deformity, saber shins, frontal bossing, Hutchison teeth and mulberry molars, sensorineural, and Clutton’s joints (painless joint effusions).

DIAGNOSIS

Image Rapid plasma reagin (RPR) titers and the flourescent treponemal antibody-absorption test (FTA-ABS).

Image Treponemes can also be seen on darkfield microscopy of nasal discharge.

TREATMENT

Penicillin G.

HIV

Image Up to 25% of pediatric human immunodeficiency virus (HIV) infection results from maternal-fetal vertical transmission.

Image Transmission from infected breast milk can occur; however, exclusively breast-fed infants have lower transmission rates.

Image Clinical features in the infant include persistent thrush, lymphadenopathy and hepatosplenomegaly, severe diarrhea, failure to thrive, and recurrent infections.

Image Strategies to reduce transmission:

Image Maternal treatment with ZDV during pregnancy.

Image Consider elective C-section at 38 weeks when feasible.

Image Mothers who are HIV positive should be advised not to breast-feed due to risk of transmission.


Image

Maternal treatment with zidovudine (ZDV) in the second trimester reduces the rate of transmission by > 70%.


DIAGNOSIS

Detection of p24 antigen in peripheral blood, PCR to detect viral nucleic acid in peripheral blood, and enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies.

TREATMENT

Nutritional support, Pneumocystis jiroveci prophylaxis, antiviral therapy, and anti-infective agents for specific infections.


Image

Delivery room management of a meconium-stained infant consists of nasopharyngeal suctioning before the delivery of the thorax. Infants with respiratory depression require intubation and tracheal suctioning.


SELECTED PROBLEMS IN FULL-TERM INFANTS

Developmental Dysplasia of the Hip (DDH)

Image Occurs in 1 in 800 births.

Image More common in white females with breech presentation, and is more likely to be unilateral and involve the left hip.

Image Signs include asymmetry of the skin folds in the groin and shortening of the affected leg.

Image Evaluation maneuvers:

Image Ortolani—abduction of the hips by using gentle inward and upward pressure over the greater trochanter.

Image Barlow—adduct the hips by using the thumb to apply outward and backward pressure; “clunking” of reduction and dislocation are elicited in patients with hip dislocation.

Image Diagnosis is confirmed by ultrasound. Current American Academy of Pediatrics (AAP) guidelines ask for ultrasound only in female infants with breech presentation and a hip click.

Image Can be treated with a special brace (Pavlik harness) or sometimes casting. See Musculoskeletal Disease/Orthopedics chapter.

Meconium Ileus/Aspiration

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A full-term male infant was born after a prolonged second stage of labor and thick meconium at delivery. He was depressed at birth, requiring intubation and suction of the meconium from below the vocal cords. His condition improved quickly, and he was vigorous at 3 minutes of life. Apgar score was 3 and 7 at 1 and 5 minutes of life, respectively. He was doing well in the well-baby nursery until at 3 hours of life, when he was noted to have dusky episode and was transferred to the special care nursery where his O2 saturation was noted to be 82% breathing room air. He was placed in oxyhood oxygen climbing up to 100% with borderline O2 saturation in the mid-80s. He was intubated and started on mechanical ventilation. His chest x-ray is shown in the figure. What is the likely diagnosis and management of this infant?

The infant described has characteristic meconium aspiration syndrome as seen by nodular appearance of both lung fields on the chest x-ray. He is developing persistent pulmonary hypertension of the newborn (PPHN), management of which includes aggressive ventilation, inhaled nitric oxide, and close monitoring of the gas exchange. An echocardiogram is useful to provide details on the elevated pulmonary pressures as well as to rule out any cardiac defects. Infants are at risk of hypotension and shunting of pulmonary flow via the ductus arteriosus into the systemic circulation resulting in differential O2 saturation in the upper and lower extremities and require pressor support (dopamine, dobutamine, epinephrine) to elevate systemic blood pressure to the level above pulmonary pressure to prevent hypotension and shunting.

Image Meconium is the first intestinal discharge of a newborn infant and is composed of epithelial cells, fetal hair, mucus, and bile.

Image Intrauterine stress may cause passage of meconium into the amniotic fluid, which can cause airway obstruction and a severe inflammatory response, → severe respiratory distress known as meconium aspiration syndrome.

Image Meconium ileus occurs when meconium becomes obstructed in the terminal ileum; presentation is with failure to pass stool, abdominal distention, and vomiting.

Image Infants with meconium ileus should be tested for cystic fibrosis.


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Meconium ileus is the most common presentation of cystic fibrosis in the neonatal period.


Hypoxic/Ischemic Encephalopathy

Image Hypoxic ischemic encephalopathy is an important cause of permanent damage to the cells of the CNS that occurs secondary to hypoxia (↓ oxygen delivery) and ischemia (↓ blood flow).

Image Can be caused by maternal conditions (hypertension), placental insufficiency, severe neonatal blood loss, and overwhelming infection.

Image Neurologic manifestations include hypotonia, coma, and seizures.

Image It can result in death, cerebral palsy (CP), and mental retardation.

Image Newer modalities of treatment include selective head cooling or whole body cooling, which are used at several tertiary care neonatal intensive care units (NICUs) in the United States.


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Ninety percent of full-term infants pass their first stool within the first 24 hours of life.



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Only 10% of patients with cerebral palsy have birth events associated with asphyxia; the cause of the majority of cases of CP remains unknown.


Congenital Diaphragmatic Hernia (CDH)

Image Associated with chromosomal abnormalities, low birth weight, and IUGR.

Image Can be diagnosed on prenatal ultrasound (between 16 and 24 weeks).

Image Signs and symptoms include respiratory distress immediately on delivery, tachypnea, poor breath sounds over affected side of chest (most commonly left), and scaphoid abdomen.

Image Prenatally diagnosed diaphragmatic hernia in a neonate warrants an exutero intrapartum treatment (EXIT) procedure, where neonatologists and surgeons are present at delivery and infant is intubated and central extracorporeal membrane oxygenation (ECMO) catheters placed at the delivery of the head and neck.

Image Respiratory distress is a cardinal sign in neonates with CDH.

Jaundice

Image Common causes of hyperbilirubinemia include ABO incompatibility, breast milk jaundice (see Nutrition chapter), Rh iso-immunization, and infection.

Image Conjugated hyperbilirubinemia (direct):

Image When an infant’s direct (conjugated) bilirubin is > 3 mg/dL or more than 20% of the total bilirubin.

Image Most common causes are idiopathic neonatal hepatitis (diagnosis of exclusion) and biliary atresia.

Image Unconjugated hyperbilirubinemia (indirect):

Image When an infant’s indirect (unconjugated) serum bilirubin level is > 10 mg/dL in term infants. Nomograms developed by AAP are used to plot bilirubin levels and to categorize infants into low or high risk group and need for treatment.

Image Most common cause of neonatal jaundice, seen in up to 50% of neonates.

Image Secondary to ↑ bilirubin load, defective uptake and conjugation, and impaired excretion into bile.

Image Physiologic hyperbilirubinemia is seen after the first 24 hours of life, peaks at 3 days, and resolves over 2 weeks.

Image Kernicterus:

Image Bilirubin neurotoxicity secondary to persistently elevated bilirubin levels, which exceed albumin-binding capacity of the blood resulting in deposition of bilirubin in the basal ganglia.

Image This can result in subtle neurologic deficits, hearing loss, profound encephalopathy, and death.

Image Treatment is initiated to prevent kernicterus.

Image Phototherapy with blue-green light converts bilirubin in skin to nontoxic isomers that are excreted without conjugation.

Image Elevated bilirubin levels (12–20 mg/dL) are usually treated with phototherapy.

Image Exchange transfusion should be considered at higher levels (20–25 mg/dL).


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High indirect serum bilirubin levels in the first 24 hours of life are never physiologic.



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In neonates there is a cephalopedal progression of jaundice; approximate levels for involvement:

Image Head and neck: 4–8 mg/dL

Image Upper trunk: 5–12 mg/dL

Image Lower trunk and thighs: 8–16 mg/dL

Image Arms and lower legs: 11–18 mg/dL

Image Palms and soles: > 15 mg/dL


NEWBORN SCREENING

Neonatal Screening

Image Available for various genetic, metabolic, hematologic, and endocrine disorders.

Image All states have screening programs, although specific tests required vary.

Image Tests performed on heel puncture include those for hypothyroidism, galactosemia, adrenal hyperplasia, cystic fibrosis, phenylketonuria, and other organic acid- and aminoacidopathies.


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Early diagnosis of hypothyroidism and treatment with thyroid hormone prior to 3 months of age can greatly improve intellectual outcome.


Auditory Screening

Image Hearing impairment can affect speech and language development and occurs in 5 in 1000 births.

Image All infants should be screened with otoacoustic emission hearing testing.



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