- Clinical science
Infants are usually born “at term,” or after 37 to 42 weeks of gestation. Approximately 10% of births are preterm, occurring prior to 37 completed weeks of pregnancy. Most infants born at term require very little medical attention in order to successfully adapt to extrauterine life. Routine management of a newborn infant immediately after birth consists of removing airway secretions, drying the newborn, and providing him or her with warmth. Health care providers also clamp and cut the umbilical cord. The Apgar score is typically used to gauge the clinical status of newborn infants at one and five minutes after birth using the following parameters: heart rate, respiratory effort, muscle tone, reflex irritability to tactile stimulation, and skin color. Infants who are born at term or late preterm and are breathing and moving satisfactorily should immediately be given to their mother for skin-to-skin contact and initiation of breastfeeding. Infants who are born prematurely, lack muscle tone, or are not breathing or crying may require supplemental oxygen or additional resuscitation.
Preventive medicine measures in the delivery room include the administration of ophthalmic antibiotics and vitamin K. Within 24 hours of birth, a detailed assessment of the newborn should take place. This typically includes a history of the pregnancy and a physical exam from head to toe, as well as measurements of length and weight.
|Presence of vital signs at birth|
|Absence of vital signs, pregnancy loss before the 20th week of gestation, and fetal weight less than 500 g|
|Infant||A child under 1 year of age|
|Newborn||A child under 28 days of age|
|Live birth between 20 0/7 weeks and 36 6/7 weeks of gestation|
|Early term infant||Live birth between 37 0/7 weeks and 38 6/7 weeks of gestation|
|Full term infant||Live birth between 39 0/7 weeks and 40 6/7 weeks of gestation|
|Late term infant||Live birth between 41 0/7 weeks and 41 6/7 weeks of gestation|
|Post term infant||Live birth later than the 42nd week of gestation|
|Small-for-gestational-age infant (SGA)||Birthweight < 10th percentile|
|Appropriate-for-gestational-age infant (AGA)||Birthweight 10th–90th percentile for gestational age|
|Large-for-gestational-age infant (LGA)||Birthweight > 90th percentile for gestational age|
|Low birth weight||Birthweight < 2,500 g regardless of the gestational age (occurs in early term infants and infants with intrauterine growth restriction; associated with increased mortality, particularly due to sudden infant death syndrome).|
|Very low birth weight||Birthweight between 1,000–1,499 g regardless of the gestational age|
|Extremely low birth weight||Birthweight < 1,000 g regardless of the gestational age|
|Perinatal period||The period from the 22nd week of gestation to the 7th day after birth|
|First 4–6 weeks after birth|
Immediate care of the newborn
- Wipe the newborn's mouth and nose to clear airway secretions; → Suction only if necessary.
- Dry the newborn.
- Provide warmth.
- Clamp and cut the umbilical cord.
- Skin-to-skin contact with mother and initiation of breastfeeding
- 1 and 5 minutes after birth assessed at
- Begin resuscitation if onset of respirations has not yet occurred (within 30–60 seconds)
- Used for clinical assessment of newborns at 1 and 5 minutes after birth
- The 1-minute Apgar score is not used to determine the need for , which should begin if necessary before the score is assigned.
Assessment of 5-minute Apgar score: infants with scores < 7 may require further intervention
- Reassuring: 7–10
- Moderately abnormal: 4–6
- Low: 0–3
|0 Points||1 Point||2 Points|
|Appearance (skin color)||Blue (cyanotic) or pale||Pink trunk, blue extremities (acrocyanosis)||Pink body and extremities|
|Pulse (heart rate)||None||< 100 beats/min||≥ 100 beats/min|
|Grimace (reflex irritability upon tactile stimulation)||None||Grimace||Cry or active withdrawal|
|Activity (muscle tone, movement)||No movement, limp body||Some flexion||Active motion, flexion|
|Respirations||None||Weak cry, irregular/slow/weak breathing or gasping||Regular breathing, strong cry|
The Apgar score is useful for evaluating the status of a newborn infant, but it should not be used to draw conclusions about individual neonatal morbidity or mortality and it should not be used as a long-term prognostic tool!
- Infants who are born prematurely, lack muscle tone, or are not breathing or crying may require some type of medical intervention.
- High-risk deliveries should have a health care provider experienced in neonatal resuscitation on hand.
- Begin pulse oximetry
- Positive pressure ventilation with bag mask
- Chest compressions if heart rate is < 60 bpm despite adequate ventilation for 30 seconds
- IV epinephrine if heart rate < 60 bpm despite adequate ventilation and chest compressions for at least 30–60 sec
Preventive measures directly after birth
- Ophthalmic antibiotics: to prevent gonococcal conjunctivitis (erythromycin ophthalmic ointment)
- Vitamin K: to prevent vitamin K deficient bleeding (VKDB)
Measurement and a detailed examination of the newborn should take place within the first 24 hours of life.
- Vital signs
- Bilirubin: see
- pH: ≥ 7.2 (slightly more acidic than adults)
- Urine and meconium
- Feeding: encourage and provide counseling regarding breastfeeding
- Losing weight after birth
- Consequences of intrauterine estrogen exposure
Healthy newborn infants normally lose up to 7% of their original birth weight in the first 5 days of life. This weight is then gained back through drinking breast milk and/or formula by age 10–14 days. No treatment is necessary!
External signs of maturity
- Skin color and texture: rosy
- Body hair: lanugo may be present, thinning, or mostly absent
- Eyes: open
- Ears: well formed pinna (auricular cartilage) that instantly recoils
- Breast: clearly discernible areola
- Testicles: descended
- Labia: labia minora covered by labia majora
- Plantar creases: cover the entire soles of the feet
- Definition: venous hematocrit (HCT) greatly exceeding normal values for gestational and postnatal age
- Risk factors
- Clinical features
- Diagnosis: : Venous HCT > 65%
Treatment (if symptomatic)
- IV hydration
- Possible partial exchange transfusion (PET)
- Definition: erythema toxicum is 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
- 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
- Definition: benign blue-gray pigmented skin lesion of newborns
- Asian and Native American: 85–100%
- African American: > 60%
- Hispanic: 46–70%
- White: < 10%
- Pathogenesis: melanocytes migrating from the neural crest to the epidermis during development become entrapped in the dermis
- Blue-gray pigmented macule (may also be green or brown)
- Diameter: typically < 5 cm, may be > 10 cm
- Location: most common on the back; , also seen on the buttocks; , flanks, and shoulders
- Prognosis: : usually resolves spontaneously during childhood (typically by the age of 5)
- Epidemiology: 1/20,000 births
- Clinical features
- Treatment: surgical excision or laser treatment (depending on type and size of lesion)
- Prognosis: Large nevi are at risk of degeneration → frequent follow-up
- Definition: benign vascular tumors of infancy
- Occurs in up to 10% of infants
- Mostly affects girls
- Clinical features
- Based on clinical findings
- The differential diagnosis of is found mostly in adults.
- Active non-intervention (monitoring, parental education)
- Systemic therapy with propranolol in complicated cases:
If unresponsive to medication:
- Laser therapy
- Resection if necessary
- Usually good prognosis
- Spontaneous resolution is common (70% by age 7)
- Visual impairment in untreated periorbital hemangioma
- Milia neonatorum: tiny epidermal papules on the face caused by the buildup of keratin and sebaceous secretions. These pinhead-sized lesions resolve without treatment.
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
- Clinical findings: typically unilateral, blanchable, pink-red patches that grow and become thicker and darker with age
- Prognosis: benign skin lesion
- Treatment: cosmetic laser treatment if desired (not necessary)
- Some skin manifestations, and should be differentiated from benign skin lesions in the newborn. may present with rashes or other
In the US, each state has its own newborn screening program, and the conditions screened for vary from state to state.
- The U.S. Department of Health and Human Services has made some recommendations. For a comprehensive list of recommended uniform screening panels, see the “Tips & links” section.
- Most of the tests are performed on filter paper using a few drops of blood from a newborn's heel.
- Optimal time for screening: 36–72 hours after birth
- Metabolic conditions
- Hemoglobinopathies, including ; and
- Hearing loss (otoacoustic emissions and/or auditory brainstem response)
- Critical congenital heart defects
- Severe combined immunodeficiencies (SCID)
- Pompe disease) (
- Biotinidase deficiency
- Endocrine conditions