Overview of neonatal conditions

Neonatal conditions manifest during the first 28 days of life and can affect any organ system. This article includes an overview of neonatal conditions by organ system with additional information on macrosomia, neonatal skin conditions (e.g., erythema toxicum neonatorum, congenital dermal melanocytosis), neonatal hypoglycemia, hematologic conditions (e.g., physiologic anemia of pregnancy, neonatal polycythemia), and infantile colic.

For information about routine newborn care, see “The newborn infant.”

Skin

• Neonatal skin lesions

Head

• Head molding
• Caput succedaneum
• Cephalohematoma
• Subgaleal hemorrhage
• Bulging fontanelles as a sign of increased intracranial pressure
• Facial nerve palsy due to birth trauma

Eyes

• Retinopathy of prematurity
• Newborn conjunctivitis
• Leukocoria (may indicate retinoblastoma)

Ear, nose, and mouth

• Cleft lip or cleft palate
• Choanal atresia

Neck and clavicles

• Birth-related clavicle fracture
• Infant torticollis

Circulatory system

• Neonatal respiratory distress syndrome
• Cyanotic and acyanotic congenital heart defects

Gastrointestinal tract

• Hirschsprung disease
• Necrotizing enterocolitis
• Vitamin K deficiency bleeding of the newborn

Urogenital system

• Congenital adrenal hyperplasia
• Neonatal acute kidney injury

Trunk, spine, and extremities

• Infantile hypotonia
• Neural tube defects
• Foot deformities (e.g., club foot, metatarsus adductus)
• Hip dysplasia
• Brachial plexus injuries

Endocrine organs

• Neonatal hypocalcemia
• Congenital hypothyroidism
• Congenital hyperinsulinism
• Neonatal diabetes
• Congenital hypopituitarism

Hematological system

• Physiologic anemia of infancy
• Neonatal polycythemia

• Definition: a fetus that is > 4000 g (8 lbs 13 oz), regardless of gestational age
• Etiology ^[1]
  • Diabetes mellitus in pregnancy
  • Previous macrosomic fetus
  • Multiparity
  • Maternal obesity
  • Excessive gestational weight gain
  • Maternal birth weight (> 4,000 g or 8 lbs 13 oz)
  • Postterm pregnancy
  • Genetic and congenital disorders (e.g., Beckwith-Wiedemann syndrome)
• Pathophysiology ^[1]
  • Maternal hyperglycemia → fetal hyperglycemia → stimulation of fetal pancreas → fetal hyperinsulinemia → ↑ insulin, insulin-like growth factors, growth hormone, and other growth factors → ↑ fetal growth, fat deposition, hepatic glucose uptake, and glycogen synthesis → ↑ delivery to insulin-sensitive tissues (e.g., heart, liver, skeletal muscle)
  • ↑ Maternal lipid levels → ↑ supply of fatty acids to the fetus and fetal hyperinsulinemia → incorporation of fatty acids into fetal adipocytes → ↑ fetal adiposity
• Diagnostics: > 4000 g (8 lbs 13 oz), as estimated by ultrasound measurements (e.g., fetal abdominal circumference)
• Complications
  • Fetal
    • Birth injuries (e.g., shoulder dystocia, brachial plexus injury)
    • Acute respiratory distress, transient tachypnea of the newborn
    • Neonatal hyperbilirubinemia
    • Neonatal polycythemia
    • Neonatal hypoglycemia
    • Metabolic acidosis
    • Stillbirth
    • Long-term complications (e.g., insulin resistance, obesity)
  • Maternal
    • Genital tract lacerations
    • Postpartum hemorrhage
    • Uterine rupture
    • Protracted or arrested labor
• Prevention
  • Individuals with diabetes mellitus in pregnancy should achieve adequate glycemic control.
  • All pregnant individuals should avoid excessive weight gain.

Erythema toxicum neonatorum

• Definition: : a benign, self-limiting rash that appears within the first week of life
• Etiology: unknown (probable contributing factors: immature sebaceous glands and/or hair follicles)
• Clinical features
  • Small, red macules and papules that progress to pustules with surrounding erythema
  • Located on trunk and proximal extremities
  • Spares the palms of hands and soles of feet
• Diagnostics
  • Based on clinical appearance of rash
  • Biopsy or smear of pustula (rarely necessary): ↑ eosinophils
• Treatment: observation only
• Prognosis: : typically resolves without complications within 7–14 days

Congenital dermal melanocytosis (Mongolian spot)

• Definition: benign blue-gray pigmented skin lesion of newborns
• Neonatal prevalence ^[2]
  • Asian and Native American: 85–100%
  • African American: > 60%
  • Hispanic: 46–70%
  • White: < 10%
• Pathophysiology: melanocytes migrating from the neural crest to the epidermis during development become entrapped in the dermis
• Clinical features
  • Blue-gray pigmented macule (may also be green or brown)
  • Location: most common on the back, also seen on the buttocks, flanks, and shoulders
  • Diameter: typically < 5 cm, may be > 10 cm
• Diagnostics
  • Based on clinical appearance
  • It is important to document the diagnosis of Mongolian spots, as they may resemble bruises and lead to false suspicions of child abuse.
• Prognosis: : usually resolves spontaneously during childhood (typically by the age of 10 years) ^[3]

Congenital melanocytic nevus

• Definition: a congenital skin lesion caused by the proliferation of melanocytes
• Epidemiology: 1/20,000 births ^[4]
• Clinical features ; ^[4]
  • Light to darkly pigmented, well-circumscribed macule or patch
  • Often with increased hair growth
  • Vary in size: < 1.5 cm to > 20 cm
  • A nevus larger than 20 cm in size is referred to as a giant congenital melanocytic nevus
• Treatment: surgical excision or laser ablation (depending on type and size of lesion)
• Prognosis: large nevi are at risk of degeneration → frequent follow-up

Infantile hemangioma (strawberry hemangioma)

• Definition: benign capillary vascular tumor of infancy
• Epidemiology
  • Occurs in 3–10% of infants ^[5]
  • More commonly affects girls
• Pathophysiology
  • Abnormal development of vascular endothelial cells
  • Rapid proliferation followed by subsequent spontaneous slow involution (occurring at the age of 5–8 years) ^[6]
• Clinical features
  • Manifests during the first few days to months of life
  • Progressive presentation; : blanching of skin → fine telangiectasias → red painless papule or macule (strawberry appearance)
  • Most commonly on head and neck
  • Usually solitary lesions
• Diagnostics
  • Based on clinical findings
  • The differential diagnosis of cherry angioma is found mostly in adults.
• Treatment
  • Active nonintervention (monitoring, parental education)
  • Systemic therapy with propranolol in complicated cases
    • Rapidly growing cutaneous hemangiomas
    • Periorbital hemangioma: vascular anomaly in the periorbital region, most commonly the upper eyelid
    • Hemangiomas in the airways, gastrointestinal tract, or liver
    • Hemangiomas with high risk of complications
  • If unresponsive to medication
    • Cryotherapy
    • Laser therapy
    • Resection if necessary
• Complications
  • Ulceration
  • Disfigurement
• Prognosis
  • Usually good prognosis
  • Spontaneous resolution is common
  • Visual impairment if periorbital hemangioma is left untreated

Others

• Milia neonatorum
  • Definition: tiny epidermal papules caused by the buildup of keratin and sebaceous secretions
  • Clinical features: pinhead-sized lesions located on the face/trunk
  • Treatment: not necessary
  • Prognosis: benign skin lesion, spontaneous resolution without scarring
• Capillary malformations (naevus flammeus, port-wine stain, firemark)
  • Definition: congenital, benign vascular malformations of the small vessels in the dermis
  • Epidemiology: may occur in association with a neurocutaneous disorder such as Sturge-Weber syndrome
  • Clinical features: typically unilateral, blanchable, pink-red patches that grow and become thicker and darker with age
  • Treatment: cosmetic laser treatment if desired (not necessary)
  • Prognosis: benign skin lesion
• Transient neonatal pustular melanosis (TNPM)
  • Definition: a benign, transient, idiopathic neonatal skin condition
  • Epidemiology ^[7]
    • Incidence: ∼ 2%
    • Most commonly occurs in African American infants (5 %)
  • Clinical features
    • Solitary or clustered pustules and vesicles on a nonerythematous base
    • Hyperpigmented, erythematous macules and collarettes of fine scale
    • Most commonly affects the forehead, anterior neck, and lower back
  • Treatment: reassurance
  • Prognosis: benign, self-limiting skin lesion
• Nevus anemicus
  • Definition: a pale patch of skin that does not create erythema in response to trauma, heat, or cold
  • Etiology: caused by a vascular anomaly (increased sensitivity of cutaneous blood vessels to naturally occurring catecholamines)
  • Treatment: not required
• LEOPARD Syndrome (Noonan syndrome with multiple lentigines)
  • Lentigines: lenticular hyperpigmentation (dark macules)
  • Electrocardiographic conduction abnormalities
  • Ocular hypertelorism
  • Pulmonary stenosis
  • Abnormalities of genitalia
  • Retardation of growth
  • Deafness
  • See “Noonan syndrome” in “Rare inherited syndromes.”
• Neonatal acne
• Blueberry muffin syndrome
  • A descriptive term for neonates born with multiple bluish, purple marks in the skin, which can be due to extramedullary erythropoiesis, purpura, or metastases.
  • The differential includes various cancers (e.g., rhabdomyoscarcoma), blood disorders (e.g., hemolytic disease of the new born), and congenital viral infections (e.g., rubella)

Some congenital infections may manifest with rashes or other skin conditions and should be differentiated from benign skin lesions in the newborn.

• Definition: low blood glucose in a newborn
• Subtypes
  • Transitional neonatal hypoglycemia: a normal physiological drop in a newborn's plasma glucose levels within the first 2 hours of life that typically resolves within 72 hours of birth
  • Persistent neonatal hypoglycemia: low plasma glucose levels (< 50 mg/dL) in a newborn that persist beyond the first 48 hours of life
• Risk factors ^[8][9]
  • Persistent hyperinsulinemic hypoglycemia (e.g., due to gestational diabetes)
  • Prematurity
  • Intrauterine growth restriction
  • Small for gestational age
  • Large for gestational age
  • Persistent hypoglycemia
    • Perinatal stress (e.g., sepsis, maternal preeclampsia or eclampsia)
    • Congenital syndromes (e.g., Beckwith-Wiedemann syndrome)
    • Congenital hyperinsulinism or hypopituitarism
    • Postterm infants
• Pathophysiology
  • Inadequate glycogen stores and/or impaired glucose production
  • Increased glucose utilization
    • Maternal hyperglycemia → fetal hyperglycemia → beta cells hypertrophy and hyperfunctioning → fetal and neonatal hyperinsulinemia → delivery → ↓ maternal glucose supply → transient hypoglycemia
    • Insufficient glycogen stores and hyperinsulinemia → impaired hepatic glycogen mobilization → transient hypoglycemia
• Clinical features
  • Usually asymptomatic
  • Autonomic symptoms (e.g., tachycardia, sweating, tremors)
  • Neurological symptoms (e.g., hypotonia, irritability, poor feeding, lethargy, seizures)
• Diagnostics: Glucose levels should be obtained for symptomatic infants and/or those with known risk factors. ^[9][10][11]
  • Asymptomatic infants: blood sugar levels < 45 mg/dL within 24–48 hours or < 50mg/dL thereafter
  • Symptomatic infants: blood sugar levels < 40 mg/dL within the first 48 hours or < 50mg/dL thereafter
• Treatment ^[8]
  • Close glucose level monitoring for the first 24–48 hours
  • Oral or IV glucose supplementation, if necessary.
• Prognosis ^[9]
  • Transient hypoglycemia: glucose levels typically increase and stabilize between 45 and 80 mg/dL by the first 72 hours
  • Persistent hypoglycemia: prognosis depends on the underlying etiology.

• Definition: a physiologic decrease in RBC production that typically appears at 8–12 weeks of age in term infants and 4–8 weeks of age in preterm infants
• Pathophysiology ^[12]
  • Increase in oxygenation → ↑ in tissue oxygen levels → ↓ production of erythropoietin
  • Shorter lifespan of erythrocytes (60–90 days in term infants and 35–50 days in preterm infants)
• Clinical features
  • Term infants: typically asymptomatic
  • Preterm infants: rapid decline of HB that may be more severe, often manifesting with pallor, apnea, lethargy, and/or poor feeding
• Diagnostics: screening for anemia should be performed at 12 months of age via measurement of Hb levels. ^[13]
• Differential diagnoses
  • Blood loss (e.g., due to frequent sampling)
  • Increased RBC destruction (e.g., due to immune hemolytic anemia, hereditary spherocytosis)
  • Decreased RBC production (e.g., due to congenital hypoplastic anemia)
• Treatment ^[12]
  • Term infants: physiologic anemia is typically well tolerated; no treatment is necessary.
  • Preterm infants: Treatment is indicated if Hb levels are < 7 g/dL.
    • Optimization of feeding with iron supplementation
    • Blood transfusion may be considered in symptomatic patients with reticulocytopenia.

• Definition: venous hematocrit (HCT) greatly exceeding normal values for gestational and postnatal age
• Epidemiology: 1–5% of newborns ^[14]
• Risk factors
  • SGA
  • LGA
  • Infants of diabetic mothers
  • Delayed umbilical cord clamping
  • Intrauterine hypoxia (e.g., maternal tobacco use)
  • Twin-to-twin transfusion syndrome (recipient)
  • Chromosomal abnormalities
• Pathophysiology
  • Maternal hyperglycemia → chronic fetal hyperglycemia → ↑ metabolic effects and oxygen demand → fetal hypoxemia → ↑ erythropoietin concentrations
  • Delayed umbilical cord clamping → erythrocyte transfusion → ↑ circulating red blood mass (HCT)
  • Placental insufficiency or chronic intrauterine hypoxia → increased intrauterine erythropoiesis → ↑ circulating red blood mass (HCT)
• Clinical features
  • Respiratory distress, cyanosis, apnea
  • Poor feeding, vomiting
  • Hypoglycemia
  • Plethora
  • Lethargy and irritability
  • Tremors or seizures
• Diagnostics
  • Venous HCT > 65%
  • Hemoglobin > 22 g/dL
• Treatment (if symptomatic)
  • Monitoring
  • IV hydration
  • Partial exchange transfusion: a procedure in which part of the blood is replaced with an isotonic fluid to lower the hematocrit
    • Indicated in asymptomatic patients with high hematocrit (> 75%) or symptomatic patients with hematocrit > 65% ^[15]
    • Increased risk of NEC ^[16]
• Complications
  • Hypoglycemia
  • Hyperbilirubinemia
  • Hyperviscosity syndrome
  • Low iron stores
  • NEC

• Etiology
  • Unknown
  • Gastrointestinal (e.g., overfeeding or underfeeding, aerophagia, cow's milk intolerance)
  • Biologic (e.g., increased serotonin levels, tobacco exposure, dysfunctional motor regulation related to immaturity)
  • Psychosocial factors (e.g., exposure to stress)
• Clinical features
  • Otherwise healthy infant with appropriate weight gain
  • Paroxysmal episodes of loud and high pitched crying that often occur at the same time each day (usually in the late afternoon or evening)
  • Hypertonia (e.g., clenched fists, stretched legs) during episodes
  • Infant is not easily consoled
• Diagnostics: crying that lasts ≥ 3 hours per day, ≥ 3 days per week, for ≥ 3 weeks in an otherwise healthy infant < 3 months
• Treatment
  • Reassurance
  • Soothing techniques
  • Trial of various feeding techniques