Preterm infants

Definition: newborn infant born before 37 weeks gestation.

Causative factors of preterm birth

1- Maternal

a- Incompetent cervix.                     b- Pre-eclampsia.

c- Antepartum hemorrhage.             d- Severe maternal illnesses e.g. heart disease.

e- Polyhydramnios.                          f-Premature rupture of membranes.

g- Smoking and /or alcoholism in pregnancy.

h- Poor socio-economic status.

2- Fetal: fetal developmental anomalies, multiple pregnancies.

3- Iatrogenic

4- Unknown

Table 7-3 Differences between pre-term, full-term

Item	Pre-term	Full-term
Gestational age	< 37 weeks	37-42 wk
Birth weight	< 2.5 kg	2.5-4.5 kg
Head circumference	<33 cm	33-37 cm
Activity	Less active	Active
Posture	Less flexion	Flexion
Body tone	Hypotonic	Normal
Head lag	Marked	Little
Ventral suspension	Head and leg drop	Sustain head and legs
Lanugo hair	Abundant	Sparse
Skin	Gelatinous red and transparent	Dark
Vernix caseosa	Thick	Thin
Nails	Pre-tips	To finger tips
Sole creases	Faint red marks	Creases anterior 2/3
Breast	Barely visible	Raised areola, 3-4 mm bud
Ear cartilage	Pinna flat, stays folded	Well curved pinna, recoil
Male genitalia	Undescended testicles, empty scrotum, faint rugae	Testicles down, good rugae
Female genitalia	Prominent clitoris, small protuberant labia minora	Majora large and minora small

Temperature control in preterm infants

Heat production is low and heat loss is high, because:

a- The surface area is large in proportion to the body’s weight.

b- There is little insulation by subcutaneous fat. Brown fat that is a source of heat production in normal term babies is deficient in preterm infants.

c- The baby’s thermostatic mechanism is also poor.

d- There is limited development of the cutaneous vascular responses and of ability to sweat.  

e- Heat production by shivering or muscle activity is minimal.

Blood and circulation

Week capillary walls and reduced clotting factors lead to greater tendency to bleed. The hemoglobin is as high as in a term infant.

Respiration

• The nasal airway is narrow and easily obstructed.

• The respiratory passages are narrow giving greater resistance to air flow.

• The thoracic cage is soft, so that it is sucked in by negative pressure during inspiration.

• The cough reflex is poorly developed.

• Gaseous exchange is relatively inefficient as pulmonary surfactant is diminished causing collapse of the alveoli.

• The mechanisms that regulate depth and rate of breathing by the respiratory centers are not fully developed resulting in an unstable respiratory system with periods of apnea.

Digestion

• The mechanism of suckling and swallowing is not well developed. It becomes sufficiently coordinated to begin to feed from the breast at about 32-34 weeks and becomes fully effective       around 36-37 weeks.

• The function of digestion matures early. Sugar is well tolerated while protein is less so and fat is least well tolerated.

• Immaturity of liver function is seen mainly as a reduced ability to conjugate bilirubin that results in an increased physiological jaundice in pre-term infants.

Renal function

The kidneys are able to excrete urea and water adequately even in very premature baby but they are unable to excrete big fluid loads and edema may result. They are also less able to retain sodium than in mature babies.

Poor resistance to infection

Transfer of maternal immunoglobulin starts at about 28 weeks with the levels increasing rapidly after 34 weeks. The most immature infants therefore have limited passive immunity and their own ability to produce antibodies is poorly developed.

Common disorders of preterm infants

  1- Respiratory problems: respiratory distress syndrome and apneic attacks.

  2- Alimentary tract problems: abdominal distension, regurgitation of gastric contents.

  3- Hyperbilirubinemia.                                                4-  Hypothermia.

  5- Hypoglycemia.                                                        6-  Hypocalcaemia.

  7- Anemia.                                                                  8-  Edema.

  9- Circulatory instability.                                            10- Infection.

  11- Cerebral anoxia.

Management of the preterm infant

Care in the delivery room

• Same measures of ordinary care given to term babies.

• Preterm baby must be handled very gently and placed in a pre-warmed towel under a source of radiant heat.

• Prompt resuscitation with endotracheal intubation and ventilation is advisable for most preterm babies of less than 32 weeks gestation to provide maximal initial expansion of the alveoli and thus reduce the severity of any subsequent respiratory distress syndrome.

• The baby should be transferred in a transport incubator at 34-35 ºC or in a warmed cot to the neonatal unit.

Subsequent care of preterm infant

1- Maintenance of body temperature and oxygen supply: incubator is the traditional equipment to provide a controlled microenvironment for preterm infant while allowing ready access to them.

2- Humidity: the relative humidity is best kept inside the incubator at about 50-60%. Humidity helps to reduce heat loss, avoid drying of respiratory tract and helps thinning of viscid secretion.

3- Precautions against cross infection

a- No nurse or medical attendant with an infection should be allowed to work in a special care unit until clear of infection.

b- Meticulous hand washing before and after handling babies is the greatest practical safeguard against transmitting infection.

c- Meticulous sterilization of the incubator and other equipment and fluids used for every baby.

d- Avoidance of air contamination and overcrowding.

4- Observation and recording of changes

During the first 24 hours, careful observation of the baby’s general state is necessary e.g. skin color, type and rate of respiration, heart rate, body temperature and any abnormal movements.

5- Feeding of preterm infants: feeding may be parenteral or enteral

Parenteral nutrition

• Most very small immature babies need their fluid and calorie requirements intravenously for   at least the first 48 hours.

• Intravascular administration of 5-10% dextrose solution is initially given for babies under   1500 gm, those with respiratory distress and all ill babies.

• More prolonged maintenance of nutrition intravascularly is made possible by giving a balanced mixture of amino acids, glucose, fats and electrolytes in what is called total parenteral nutrition ”hyperalimentation”.

Enteral nutrition

When oral feeds can be tolerated, the first one is given early, and the frequency will depend upon the maturity of the baby to be given hourly or 2 hourly for smaller infants or 3 hourly for larger babies.

The methods for giving oral feeds depend upon the size, maturity and vigor of the baby:

• Infants of more than 35 week’s gestation are usually able to take their feed directly from the breast or by bottle.

• Less mature babies depend mainly on gavage feeding using nasogastric or nasojejunal tubes.

a- Breast milk: breast milk from infant’s mother is more appropriate. It has the merit of being well tolerated, better absorbed in the gut and provides some protection against infection.

b- Formula milk: specialized preterm formula adapted for the nutritional needs of low birth weight infants is available and can be used if breast milk is not available or insufficient.

The amount of milk required depends on baby’s size, maturity and postnatal age (table 7-2). Preterm infants need more calories per unit of body weight than full term infants and an energy   value up to 150 kcal/kg is required to maintain weight gain.

Table 7-2 Average volumes of milk needed by babies under 2000 gm birth weight

Day	Volume (ml/kg/body weight/day)
1 2 3 4 5	60 90 110 150 150-180

Vitamin and iron supplementation

  Vitamin D: preterm infant has an increased liability to develop rickets after about 2 months of    age and therefore breast fed babies should receive vitamin D (1000 IU/day).

  Vitamin A: (1000 IU/kg/day) 

  Vitamin C: (50 mg/ day)

  Vitamin E: (10 mg daily): may be given to protect against hemolytic anemia.

  Folic acid: (100 μg daily) should be given to very low birth weight babies to prevent a later macrocytic anemia.

  Iron: (2.5 mg/kg daily) is given from 4-6 weeks of age onwards to prevent anemia of prematurity.

N.B: the dose of vitamins given must be adjusted according to the amounts already incorporated in the milk preparation used.

Discharge criteria of preterm babies from the neonatal unit

  1- Post conceptual age of about 36 weeks.

  2- Current weight of 1800gm or more with an average of weight gain of 15-30 gm/day.

  3- Stable temperature in an open crib.

  4- Taking all nutrition by nipple (bottle or breast).

    5- No recent apnea or bradycardia.

  6- No need for parenteral drugs or oxygen_.

Respiratory distress syndrome (RDS) of the newborn (Hyaline membrane disease)

  To maintain alveolar stability, surfactant reduces the surface tension and prevents collapse of small air spaces at end of expiration. The primary cause of respiratory distress syndrome (hyaline membrane disease) is inadequate pulmonary surfactant with consequent diffuse alveolar atelectasis, edema, and cell injury.

Risk factors

  1- Infant of diabetic mother.                              2- Pre mature infants.              

  3- Cesarean section delivery.                              4- Multi fetal pregnancies.            

  5- Asphyxia.                                                        6- A history of prior affected infants.

Clinical manifestations

• Signs of respiratory distress appear within minutes or few hours of birth (tachypnea,  grunting, intercostal         

     and subcostal retractions, nasal flaring and cyanosis).

Diagnosis:

1-      Clinical features.

2-      Blood gases.

3-      Chest X-ray.

Management of respiratory distress of the newborn

Babies with respiratory distress should be admitted to neonatal intensive care unit where facilities for investigations and respiratory support are available.

1- Respiratory monitoring

a- Clinical monitoring: by assessment of degree of respiratory distress.

b- Arterial oxygen saturation monitoring: by use of pulse oximeter to assess degree of hypoxemia.

c- Arterial blood gases: it is the most sensitive and reliable method for state of oxygenation and    acid-base balance.

3- Respiratory support

The principal goal is to ensure adequate oxygenation and ventilation.

a- Chest physiotherapy and suctioning: the aim is to mobilize secretions, clear the alveoli and airways and to improve ventilation.

b- Oxygen therapy: it is indicated in all cases of respiratory distress to correct hypoxemia and relieve cyanosis. Oxygen preferably warmed and humidified, given by head box to keep arterial levels between 55-70 mmHg and >90% saturation.

c- Assisted ventilation: it is indicated in cases with persistent hypoxemia (PaO₂≤50mmHg), hypercarbia (PaCO₂ ³ 60 mmHg) and pH<7.2.

4- Specific treatment

• Surfactant replacement therapy (delivered through endotracheal tube) for cases with hyaline     membrane disease.

• Treatment of any associated problem as specific infection i.e. antibiotic therapy.

• Fluid therapy aiming at adequate hydration and tissue perfusion.

Cyanosis

Definition: it is bluish discoloration of the skin and mucous membrane due to increased level of reduced hemoglobin (>5 g/dl).

Central cyanosis

Causes:

A- Respiratory insufficiency: may be due to:

1- Pulmonary conditions: such as:

       - Upper airway obstruction by choanal atresia.

       - Lower airway diseases as respiratory distress syndrome, transient tachypnea, meconium aspiration,    

                                  pneumonia, pneumothorax, congenital diaphragmatic hernia, pulmonary hypoplasia.

2- CNS depression as a result of drugs, intracranial hemorrhage, or anoxia; respiration   tend   to be

                                  irregular and weak and are often slow.

B- Congenital cyanotic heart disease: may be due to:

   - Transposition of great vessels

   - Pulmonary atresia.

   - Tetralogy of Fallot (presenting at a later age)

C- Methemoglobinemia

   - Congenital.

   - Acquired (e.g., nitrates, nitrites toxicity).

N.B: Episodes of cyanosis may also be the initial sign of hypoglycemia, bacteremia, meningitis, shock, or pulmonary hypertension.

Management:

1-      Oxygen therapy either by nasal cannula or mask.

2-      Mechanical ventilation by positive airway pressure.

3-      Monitoring of blood gases.

4-      Determine and treat the suspected cause.

Neonatal jaundice

Definition: is yellowish discoloration of the skin and mucous membrane and sclera due to increased level of bilirubin in the blood.

          Bilirubin metabolism

Most of bilirubin is produced from the breakdown of heme portion of erythrocyte hemoglobin. The remaining 15% to 25% of bilirubin is derived from non erythroid heme proteins (marrow and extramedullary).

 Bilirubin metabolism is initiated in the reticuloendothelial system as old or abnormal red blood cells are removed from the circulation. This bilirubin in its unconjugated or indirect form is released into the plasma.

Transport

Bilirubin bound to plasma albumin is carried to the liver and transported into the hepatocyte. Intracellulary, bilirubin is bound to ligandin (Y and  Z proteins).

Conjugation

Conjugation occurs within the smooth endoplasmic reticulum of the liver cell. This reaction is catalyzed by the enzyme glucuronyl transferase.

Excretion

Conjugated bilirubin is excreted in bile and reaches the gastrointestinal tract, intestinal flora reduces most of it to stercobilinogen and is then eliminated in stool. Remaining conjugated bilirubin may be converted back to unconjugated bilirubin by the intestinal enzyme beta-glucouronidase. Reabsorption of bilirubin from the gastrointestinal tract into the circulation back to the liver for reconjugation is called enterohepatic circulation.

Causes of neonatal hyperbilirubinemia

                              Differences between physiological and pathological jaundice

Item	Physiological jaundice	Pathological jaundice
Onset	2nd –3rd day in term infant	At any time in neonatal period
Level of total bilirubin	Up to13 mg/dL.	>13mg/dL.
Hyper bilirubinemia	Indirect	Direct, indirect or mixed
Rate of accumulation of bilirubin	<5mg/dL/ 24 hr	>5mg/dL/ 24hr
Duration of jaundice	7-10 days of age in full term and 14 days in pre-term	Jaundice may persist after the 2nd wk of life
Examination	Good general condition	Abnormal manifestations according to the cause e.g. clay colored stool, pallor, petechiae or hepatosplenomegaly.
Prognosis	Good	Kernicterus may complicate untreated unconjugated hyperbilirubinemia.

5-         

                      ;

                                               Causes of neonatal jaundice

Unconjugated hyperbilirubinemia	Mixed hyperbilirubinemia	Conjugated hyperbilirubinemia
Hemolytic jaundice a- Rh and ABO incompatibilities b- Spherocytosis. c- Red cell enzyme defects         (e.g.G6PD deficiency) d- Drugs (e.g. excess Vit. k). e- Cephalhematoma. Defective conjugation a- Physiologic jaundice. b- Crigler-Najjar syndrome. c- Congenital hypothyroidism.  d- Breast milk jaundice.	Abnormalities of liver cells a- Neonatal hepatitis b- Infections: TORCH, neonatal sepsis.	Decreased rate of excretion a- Congenital biliary atresia b- Obstruction due to  pressure on biliary passages by tumor or cyst.

   Jaundice associated with breast-feeding

The milk of some mothers contains substances that may competitively inhibit glucoronyl transferase enzyme activity.

     Clinical picture

The infants develop significant indirect hyperbilirubinemia reaching maximum concentration (10-30mg/dL) during the 2^nd-3^rd week. If nursing is discontinued for 48 hours, the serum bilirubin falls.

 Hemolytic disease of the newborn

This term denotes a hemolytic process due to Rh or A B O incompatibilities.

Rh isoimmuization:

 the mother is Rh-negative and the fetus is Rh-positive (inherited from Rh-positive father). The problem occurs after the mother has been sensitized by either mismatched blood transfusion or from fetal blood entering her circulation during a previous Rh-positive pregnancy at delivery or abortion.

The mother reacts to the fetal blood by producing antibodies that cross the placenta to attack and hemolyse the red cells in the fetal circulation. In general, the first Rh-positive baby is usually not affected and the condition becomes more severe in successive Rh-positive pregnancies.

ABO incompatibility is more common than Rh incompatibility. The mother is usually group O and the baby is group A or B.

Kernicterus (bilirubin encephalopathy)

The unconjugated, fat soluble, bilirubin is toxic to the developing brain. Kernicterus develops when unconjugated bilirubin passes the blood brain barrier and is deposited in the brain cells particularly the basal ganglia. This occurs when the levels of unconjugated bilirubin exceeds 20mg/dL in term infants but at somewhat lower levels in pre-term and those suffering from asphyxia or sepsis.

The earliest clinical manifestations include: poor feeding, lethargy, hypotonia, high-pitched cry and poor reflexes.

Later, convulsions, bulging fontanel and hypertonicity are evident.

Kernicterus usually ends in death and those who survive are left with choreoathetoid cerebral palsy, mental retardation or nerve deafness.

Direct or conjugated hyperbilirubinemia

  It is due to failure to excrete conjugated bilirubin from the hepatocyte into the duodenum. It manifests by a conjugated bilirubin over 1.5 mg/dL. It may be associated with hepatomegaly, splenomegaly, pale stools and dark urine. Conjugated bilirubin is found in urine.

Causes of direct hyperbilirubinemia

1- Liver cell injury: e.g. neonatal hepatitis.

2- Biliary atresia (intra or extrahepatic), choledochal cyst, stenosis of bile duct or inspissated   bile syndrome (secondary to increased bilirubin load). 

                              Differences between neonatal hepatitis and biliary atresia

Item	Neonatal hepatitis	Biliary atresia
Stool color  Investigations    - Serum bilirubin    - SGOT.SGPT    - Alkaline phosphatase Hepatobiliary scintegraphy Sonography of the liver Liver biopsy	Intermittent or transient pale stools Biphasic Marked Increase Mild increase Sluggish uptake, but excretion of the isotope into the biliary tract and intestine eventually occurs. No dilatation of biliary  tree  Shows distortion of lobular architecture, marked infiltration with inflammatory cells and focal hepatocellular necrosis.	Persistent pale stools Mainly direct Mild increase Marked increase Hepatocyte function is intact and unimpaired uptake, but excretion into the intestine is absent. Dilatation present in patients with extra hepatic biliary atrezia  The basic hepatic lobular architecture is intact but there are bile ductular proliferation, perilobular edema and fibrosis

Treatment of neonatal jaundice

The aim is to correct the etiologic condition and to bring down the level of serum bilirubin to prevent kernicterus. In physiologic jaundice close observation is usually all what is needed.  Early feeding and adequate hydration help the liver to conjugate bilirubin efficiently.

1- Phototherapy should be started if the bilirubin level continues to rise. This involves exposing the infant to light (usually with a wave length around 450 nm). Photodegradation converts bilirubin to a non-toxic water-soluble product that is excreted in urine. The eyes of the infants should be covered and care is needed for temperature control and fluid balance.

2- Exchange transfusion: when unconjugated bilirubin ≥ 20 mg /dL in term infant in spite of phototherapy, exchange transfusion is performed. In preterm infants exchange transfusion may be done at lower levels of bilirubin. An exchange of approximately 2 blood volumes of the infant   (2 X 85ml/kg) is needed.

3- Treatment of chronic cholestasis: a major concern is growth failure due to malabsorption and malnutrition resulting from ineffective digestion and absorption of dietary fat. Usage of a medium-chain triglyceride-containing formula, replacement of fat soluble vitamins (A,D,E and K) and micronutrients (ca, phosphate, zinc) may improve caloric balance.

Surgical interference may be needed. Liver transplantation is indicated in patients with advanced liver disease.

Neonatal infections

Neonatal infections are classified into:

1-      Congenital (TORCHS):
T:Toxoplasmosis.

O: Others as hepatitis, varicella….etc.

R:Rubella,

C: Cytomegalovirus.

H:Herpes simplex.

S:Syphilis.

2-      Acquired: e.g. tetanus neonatorum.

Risk factors

1- Maternal risk factors

 a- Premature rupture of membranes ( > 18 hr ).     b- Intrapartum fever more than 38°C.

   c- Maternal leukocytosis ( > 18,000/mm³).             d- Uterine tenderness.

   e- Premature labor.                                                  f- Maternal urinary tract infection.

   g- Antenatal or intrapartum asphyxia.

2- Neonatal risk factors

   a- Prematurity/ low birth weight.

   b- Neonates with endotracheal tubes, IV catheters, parenteral nutrition.

   c- Formula fed neonates.

   d- Congenital anomalies.

Tetanus neonatorum

Definition

It is an acute spastic paralytic illness caused by soluble exotoxin of the bacterium Clostridium tetani (tetanospasmin).

Clostridium tetani is an anaerobic motile, gram +ve, spore-forming microorganism. It is   present in soil, dust, and alimentary tracts of various animals. It forms terminal spores, like a drumstick. These spores resist boiling but not autoclaving, however vegetative forms are killed by heat, antibiotics and disinfectants. Clostridium tetani is not tissue invasive but causes illness through  a toxin called tetanospasmin.

Pathogenesis

 Clostridium tetani is usually introduced into an area of injury e.g. umbilical stump as spores. Disease develops only after spores are converted to vegetative forms and multiply in the umbilical stump. It produces tetanus toxin. The tetanus toxin binds to the neuromuscular  junction and increases neuromuscular excitability. Thus when the muscle contracts, it sustains    a maximal contraction without inhibition.

Clinical picture

 Tetanus may be localized or generalized. Tetanus neonatorum is the infantile form of generalized tetanus. The incubation period is 3-12 days or may be longer.

· The patient is fully conscious and irritable.

· Trismus or lockjaw with inability to suckle (masseter muscle spasm) is the presenting symptom in 50% of cases.

· Spasm of facial and buccal muscles leads to risus sardonicus.     

· Difficulty in suckling and swallowing leads to dysphagia and dehydration.

· Laryngeal muscle spasm may cause obstruction of the airways and stridor.

· Stiffness of neck and abdominal muscles.

· Opisthotonos position may be marked or absent.

· Tetanic seizures are sudden, severe tonic contraction with flexion and adduction of the   upper limbs and hyperextension of the legs occurring for few seconds or minutes that    gradually becomes more sustained and exhausting. These spasms can be triggered by light, sound or touch and are very painful because the patient is fully conscious.

· Dysuria or retention may occur due to spasm of the bladder neck sphincter.

· High-grade fever (40º C) may be present due to the energy consumed by the spastic muscles.

· Autonomic disturbances include arrhythmias, tachycardia, labile hypertension and cutaneous vasoconstriction.

Diagnosis

  1- Clinical picture.

  2- Umbilical stump may hold dirt, pus, or serum.

  3- Laboratory investigations.

    a- Leucocytosis: if secondary bacterial infection occurs.

    b- C. tetani may be isolated from the stump in ⅓ of the patients.

    c- CSF is normal.

Treatment

· Clean the umbilical stump.

· Human tetanus immunoglobulin, 3000-5000 units should be given IM to neutralize the circulating toxins.

· If tetanus immunoglobulin is not available, tetanus antitoxin can be given in a single dose of  50,000-100,000 units. This antitoxin is divided equally, half the dose is given IM and the other half is given IV.  About 15% of the patients will have signs of serum sickness.

· Penicillin G (100,000 U/kg/d. divided over 4-6 hours intervals for 10-14 days) is used to destroy the remaining C. tetani vegetative form. If patient is allergic to penicillin, erythromycin is effective.

· Diazepam: provides both muscle relaxation and seizure control, it is given in a dose of      0.1-0.2 mg/kg every 3-6 hours IV till the control of seizures with watching the respiratory rate. Therapy for 2-6 weeks may be required and the dose may be tapered as tetanic spasms decreases.

· In severe cases, neuromuscular blocking agents are used to produce general flaccid    paralysis that is then managed by mechanical ventilation.

· Supportive care: the patient should be placed in a dark, quiet room. Fluids, electrolytes and caloric needs should be monitored. Care of the mouth, skin, bladder and bowel functions is needed.

Prevention

1- Clean delivery practice, with sterile tools.

2- Vaccination of mothers during pregnancy in the last trimester by tetanus toxoid IM, this will protect the baby up to 4 months after delivery.

Birth injuries

Definition: mechanical and hypoxic-ischemic injury occurring during labor.

Predisposing factors

  1- Macrosomia.                                             2- Prematurity.

  3- Cephalopelvic disproportion.                    4- Prolonged labor.

  5- Abnormal presentation.                            6- Instrumentation e.g. ventose and forceps delivery.

  7- Multiple births.

I- Head injuries

1- Caput succedaneum

An area of edema of the soft tissues over the presenting part of the scalp during vertex delivery.

Clinical manifestations

Soft swelling that may extend across the middle line and cross the suture lines (external to periosteum). It usually resolves within several days of life and it may be difficult to distinguish from a cephalhematoma.

Treatment: no specific treatment is needed.

2- Cephalhematoma

A subperiosteal collection of blood overlying a cranial bone, higher frequency occurs in infants born to primiparous women.

Etiology

Rupture of blood vessels, that traverse from skull periosteum, secondary to difficult labor or mechanical trauma.  

Clinical manifestations

• It is usually limited to surface of one cranial bone.

• Bleeding is limited by suture lines.

• There is no discoloration of overlying skin.

• Swelling is not visible until several hours or days after birth (subperiosteal bleeding is a slow   process).

• A sensation of central depression suggesting underlying fracture or bony defect is usually encountered on palpation of the organized rim of cephalhematoma.

• It resolves within 2 weeks to 3 months.

Treatment

• No treatment is needed for uncomplicated cephalhematoma.

• Significant hyperbilirubinemia may result necessitating phototherapy or even exchange transfusion according to the level of serum bilirubin.

• Blood transfusion may be administered in cases with large cephalhematoma.

N.B. incision and drainage are contraindicated because of the risk of introduction of infection.

3- Intracranial hemorrhage

It commonly occurs in infants with birth weight <1500 gm. It results from trauma, asphyxia or hemorrhagic disorders.

Sites of intracranial hemorrhage

  a- Epidural, subdural or subarachnoid space.

  b- Parenchyma of the cerebrum or cerebellum.

  c- Ventricles.

Clinical manifestations

1- A silent presentation may occur in up to 50% of cases.

2- Signs of blood loss: shock, pallor, respiratory distress, disseminated intravascular coagulation. 

3- Signs of neurologic dysfunction: diminished or absent Moro reflex, hypotonia, seizures, paralysis, apnea and irregularity of respiration, cyanosis, temperature instability and bulging anterior fontanel.

Diagnosis

This is based on history of delivery, clinical manifestations and it is confirmed by cranial ultrasonography and CT scan.

Treatment

  • The infant should be handled as gently as possible and maintained in an incubator.

  • Vitamin k₁ and transfusion of fresh frozen plasma or blood are indicated.

  • Anticonvulsant drugs may be used to control seizures.

  • Respiratory support.

II- Peripheral nerve injuries

1- Brachial palsy

Paralysis of the muscles of the upper limb following mechanical trauma to the spinal roots of the brachial plexus. These injuries occur when lateral traction is exerted on the head and neck during delivery of the shoulder in a vertex presentation.

a- Erb’s paralysis: is the most common form resulting from injury of the fifth and sixth cervical nerves (C_5, C₆ ).

Clinical manifestations of Erb’s palsy

The affected infant is frequently large and asphyxiated. The affected arm is held in shoulder adduction and internal rotation, with elbow extension, pronation of the forearm, and flexion of the wrist.

Treatment

1- Partial immobilization for 1 to 2 weeks by splint in a position opposite to that held by the baby to prevent development of contracture.

2- Gentle muscle massage and passive exercises may be started after 1 week and up to 3 months.

3- If paralysis persists without improvement, neuroplasty is needed.

b- Klumpke paralysis: injury to the 7^th and 8^th cervical nerves and 1^st thorathic nerve produces a paralyzed hand.

2- Facial nerve palsy

It results from pressure over facial nerve during labor. When the infant cries, the mouth is deviated to the non-paralyzed side. On the affected side, the eye cannot be closed and the nasolabial fold is absent.

Improvement occurs within a few weeks. Care of the exposed eye is essential. Neuroplasty may be indicated when the paralysis is persistent.

III- Intra-abdominal injuries

These involve rupture or sub capsular hemorrhage of the liver, spleen or adrenal gland.

Clinical picture

History of a difficult delivery, sudden shock and abdominal distension. Gradual onset of jaundice, pallor, poor feeding, tachypnea or tachycardia may be present.

Diagnosis

It is confirmed by abdominal ultrasonography.

Treatment

Laparotomy is indicated in cases of hepatic or splenic injuries and surgical repair of a laceration   may be required.

Down syndrome

Genetic types of Down syndrome

1- Trisomy 21,regular: 95% of Down syndrome is due to non-disjunction, failure of separation of chromosome 21 during cell division in oogenesis leads to an ovum containing 24 chromosomes, and the resulting zygote after fertilization by normal sperm (23) will contain 47 chromosomes with three members of chromosomes 21 instead of two. The reason  of the occurrence of trisomy 21 with advancing maternal age is unknown. However aging of the ovum may be a factor.

2- Translocation: it occurs in 4% of cases. The translocated segment of chromosome 21 fuses at the centromere with either chromosomes 13, 14, 15 or 21. The most frequent is 14, 21 translocation. The patient with translocation has 46 chromosomes but it is actually trisomic for chromosome 21. Clinically translocation Down syndrome is not distinguishable from regular trisomy. 

3- Mosaicism: it occurs in 1% of cases. Mosaicism may be defined as the presence of an individual who has two different cell lines. It results from non-disjunction after the first cell line mitotic division in zygote. The extent of the mosaicism will depend on the degree and timing of this event.

Clinical features of Down syndrome

· The most significant feature of Down syndrome is the mental retardation which is invariably present. The I.Q. ranges from 20-75 with a mean of 50. The temperament of the mongolian child is usually quiet.

· During the first year of life, hypotonia and laxity of joints are often evident. 

· Sitting, standing and walking are all delayed.

· Stature tends to be short.

· The features of Down syndrome are usually evident at birth.

· The skull circumference is usually below normal (microcephaly).

· Brachycephaly: with occipital flattening of skull.

· The fontanels may be late in closing.

· The hair is often fine and soft and may be sparse.

· The eyes slant upwards and outwards from the bridge of the nose and there are marked medial epicanthic folds. The iris may show Brushfield’s spots (whitish spots like grains of salt scattered round the iris). Squint and cataract may occur.

· The nasal bridge tends to be flattened and the nose is short.

· The tongue is somewhat pointed, often fissured and may protrude from the lips because of small mouth cavity.

· Eruption of the teeth is frequently delayed and their position is irregular.

· The ears are usually small and may lack normal cartilage formation.

· The neck is often short.

· The limbs are usually short with broad hands.

· The fifth finger is often short and incurved (clinodactly). Single fifth finger crease and hypoplasia of middle phalanx of 5^th finger may be present.

· A bilateral single palmar crease (simian crease) is common .

· There is often a wide gap between the first and second toes.

· Cardiac anomalies, commonly ventricular septal defect occurs in approximately 20% of cases. Duodenal atresia is not uncommon.

· Delayed appearance of secondary sex characters is usual.

· There is an increased liability to leukemia and infections.

Diagnosis: it is based on clinical features and chromosomal study (karyotyping).

Complications of Down syndrome

1- Intercurrent infections especially chest infection.   

2- Leukemia.

3- Lethal anomalies or accidents.                                 

4- Sudden unexpected death.

Fig. 15-8 Karyotyping of mongol., note the trisomy of chromosome 21.

Management

Other than supportive and rehabilitation management, no specific therapy is available.  

Genetic counseling helps to avoid further affected siblings.