Birthweight Variations and SGA Etiologies

Birthweight Variations

• Multiple factors influence fetal growth:
  • Nutrition
  • Genetics
  • Placental Function
  • Environment
• Newborns are classified by birthweight and weeks of gestation

Etiologies of Small Size for Gestational Age (SGA) at Birth

• Maternal Factors:

  • Young or advanced maternal age
  • Short stature and thinness before pregnancy
  • Poor weight gain during the latter third of pregnancy
  • Illness during pregnancy (diabetes, preeclampsia)
  • Nulliparity
  • Failure to obtain normal medical care
  • Substance abuse
  • Lower socioeconomic status
  • African-American ethnicity (in the U.S.)
  • Uterine and placental anomalies
  • Polyhydramnios
  • Intrauterine infections

• Fetal Factors:

  • Chromosomal abnormalities and syndromes
  • Metabolic disorders
  • Congenital infections (toxoplasmosis, rubella, cytomegalovirus)

• Medications:

  • Amphetamines
  • Antimetabolites (aminopterin, busulfan, methotrexate)
  • Bromides
  • Cocaine
  • Ethanol
  • Heroin and other narcotics (morphine, methadone)
  • Metals (mercury, lead)
  • Phencyclidine
  • Polychlorinated biphenyls (PCBs)
  • Propranolol
  • Steroids
  • Tobacco (carbon monoxide, nicotine, thiocyante)
  • Toluene
  • Trimethadione
  • Warfarin

• Placental and Uterine Abnormalities:

  • Avascular villi
  • Decidual or spiral artery arteritis
  • Infectious villitis (TORCH infections)
  • Multiple gestation (limited endometrial surface area, vascular anastomoses)
  • Multiple infarctions
  • Partial molar pregnancy
  • Placenta previa and abruption
  • Single umbilical artery, umbilical thrombosis, abnormal umbilical vascular insertions
  • Syncytial knots
  • Tumors

Characteristics of SGA Newborns:

• Disproportionately large head compared to the rest of the body
• Wasted appearance of extremities
• Reduced subcutaneous fat stores
• Jittery secondary to hypoglycemia
• Decreased amount of breast tissue
• Scaphoid abdomen (sunken appearance)
• Temperature instability
• Wide skull sutures secondary to inadequate bone growth

Nursing management for SGA Newborns:

• Monitor blood glucose levels within 30 minutes of birth, repeat the screening every hour
• Prevent hypoglycemia in neonate, blood glucose value below 40mg/dL, initiate feedings, which can be formula or breastmilk, intravenous glucose supplementation
• Monitor and record intake and output and obtain daily weights to aid in evaluating nutritional intake.

Large for Gestational Age (LGA)

• Newborns with birthweight above the 90th percentile on the growth chart and more than 4,000 g (8lb 13 oz)

Maternal factors of LGA

• Diabetes
• Multiparity
• Post term gestation
• Maternal obesity
• Paternal height
• Gestational weight gain
• Male fetus

LGA characteristics:

• Large body
• Plump appearance
• Full-faced

Nursing Management

• Monitor feeding tolerance, sucking and swallowing ability.
• Monitor vital signs status being particular alert for changes in respiratory distress
• Obtain weight, length, and head circumference comparing them with standards, and documenting the findings on standard sized chart
• Monitor blood glucose levels within 30 minutes of birth and repeat the screening every hour
• Prevent hypoglycemia in neonate, blood glucose value below 40mg/dL, initiate feedings, which can be formula or breastmilk, intravenous glucose supplementation
• Initiate early and frequent oral feedings unless contraindicated, Neonatal hypoglycemia is the major cause of brain injury
• Monitor and record intake and output and obtain daily weights to aid in evaluating nutritional intake.

Gestational Age Variations

• Preterm infant: born before 37 completed weeks of gestation
• Late preterm infant (near term): 34 0/7 to 36 6/7 weeks
• Full term infant: 38 through 41 completed weeks of gestation
• Postterm infant: 42 weeks or more

Postterm Newborn (Post Mature Infant)

• The ability of the placenta to provide adequate oxygen and nutrients to the fetus after 42 weeks gestation is compromised
• In most situations, birth of the newborn requiring special care was not anticipated.

Postterm newborns characteristics:

• Dry, cracked, peeling, wrinkled skin
• Limited/absent vernix caseosa and lanugo
• Long, thin extremities
• Creases that cover the entire soles of the feet
• Wide-eyed, alert expression
• Abundant hair on scalp
• Thin umbilical cord
• Long fingernails
• Meconium-stained skin and fingernails

Nursing management:

• Monitor and maintain blood glucose levels once stabilized.
• Reduce risk of hypothermia- thoroughly dry, wrap in warmed blanket, place stockinet cap on newborns head, provide environmental warmth.
• Intravenous dextrose 10% or early initiation of feeding will help stabilize the blood glucose levels.
• Provide hydration.

Preterm Newborn

• Newborns can be immature, affecting transition from intrauterine to extrauterine life, placing them at risk for complications.

Physical Characteristics

• Birthweight less than 5.5 lb
• Scrawny appearance
• Head disproportionate larger than chest circumference
• Poor muscle tone and flexion
• Fontanel wide and soft with overriding sutures
• Minimal subcutaneous fats
• Undescended testes
• Plentiful lanugo (soft, downy hair) especially over the face and back
• Poorly formed ear pinna, soft pliable cartilage
• Fused eyelids
• Prominent clitoris and labia minora in females

Other preterm newborn characteristics

• Matted scalp hair, woolly in appearance
• Absence to a few creases in the soles and palms
• Minimal scrotal rugae in male infants
• Thin, transparent skin with visible veins
• Breast and nipples not clearly delineated
• Abundant vernix caseosa

Preterm Newborn: Respiratory system

• Surfactant deficiency, leading to development of respiratory distress syndrome
• Unstable chest wall, leading to atelectasis
• Immature respiratory control centers, leading to apnea
• Smaller respiratory passages, leading to an increased risk for obstruction
• Inability to clear fluid from passages, leading to transient tachypnea

Preterm Newborn: Gastrointestinal System

• Lack of neuromuscular coordination required to maintain the suck, swallowing, and breathing
• Shunting of blood from the gut to more important organs
• Small stomach capacity, limited ability to digest proteins and absorb nutrients,
• Weak or absent suck and gag reflex
• Malnutrition and weight loss

Preterm Newborn: Renal system

• Immature renal system, reducing the baby's ability to concentrate urine and slowing the glomerular filtration rate
• Risk for fluid retention, fluid and electrolyte disturbances increases
• Drug toxicity because of limited ability to clear drugs from their system
• Immature immune system increasing susceptibility to infection

Preterm Newborn: Immune System

• IgG deficiency occurs because transplacental transfer does not occur until after 34 weeks gestation
• Thin skin and fragile blood vessels provide a limited protective barrier

Preterm Newborn: Central Nervous System

• Difficulty in temperature regulation and maintaining stability. (Heat loss is due to inadequate amount of insulating subcutaneous fats, muscle tone and flexion; inadequate brown fats to generate heat.)
• Susceptible to hypoglycemia due to immature glucose control mechanism, decreased glucose stores, reduced availability of alternative fuels

Preterm Newborn: Nursing Management

• PROMOTE OXYGENATION Preterm infant lacks surfactant, which lowers surface tension in the alveoli and stabilizes them to prevent collapse
• MAITAINING THERMAL REGULATION:
  • Four mechanisms for heat transfer and ways to prevent loss:
  • Convection: heat loss through air current (avoid drafts near the newborn)
• Radiation: keep isolettes away from cold sources and provide insulation to prevent heat transfer
• Conduction: warm everything the newborn comes in contact with
• Evaporation: Liquid into vapor (keep the baby dry and delay the first bath until stable)
• Observe clinical signs of cold stress such as respiratory distress, central cyanosis, hypoglycemia, lethargy, PROMOTING NUTRITION AND FLUID BALANCE

Acute Conditions Of The Neonates

• Neonates' acute conditions discussed:
• Respiratory Distress Syndrome
• Meconium Aspiration
• Hyperbilirubinemia
• Intussusception
• Trisomy 21
• Neural Tube Defects
• Meningocele
• Myelomeningocele
• Hydrocephalus
• Imporferate Anus
• Cleft lip palate
• Otitus Media
• Ottus Externa
• Failure to Thrive

Respiratory Distress Syndrome

• Breathing disorder resulting from lung immaturity and a decrease in alveolar surfactant,
• Alveoli collapsed at the end of expiration without surfactant
• Can lead to Hypoxia and acidosis
• RDS is not always treatable, condition will only worsen

Nursing management for Respiratory Distress Syndrome

• Closely monitor vital signs, acid-base status ad Arterial blood gases.
• Anticipate the administration of surfactant
• Monitor oxygen saturation levels continuously and assess pulse oximeter values
• Give respiratory support until level improves
• Mechanical ventilation and oxygen replacement, if worsens

MECONIUM ASPIRATION SYNDROME

• Occurs when the newborn inhales particulate meconium mixed with amniotic fluid into the lungs while still in utero or on taking the first breath after birth
• It is sterile and does not contain bacteria, the primary factor that differentiates it from stool.

Nursing assessment for MEOCNIUM ASPIRATION SYNDROME

• Assess amniotic fluid for meconium staining
• Note any yellowish-green staining of the umbilical cord, nails and skin
• Barrel-shaped chest with an increased anterior posterior diameter
• Nurse MUST make sure a provider is there upon delivering a new born.

HYPERBILIRUBINEMIA

• Accumulation of excess bilirubin in blood serum
• Total bilirubin level above 5mg/dL resulting from unconjugated bilirubin being deposited in the skin and mucous membrane.
• Physiologic Jaundice is unconjugated a hyperbilirubinemia during the first natal day, last up to 1 week
• Total serium level peaks in 3-5days
• 60% term infants 80% perm babies
• High red cells built up in utro is being reduced

Nursing management:

Early initiation of feedings

• Phototherapy- convert unconjugated bilirubin to the less toxic water-soluble form that can be excreted. • Special blue wave lights are placed above the newborn, exposing as much skin as possible. The lights are placed 12 to 30 inches above the newborn bassinet or incubator.
• Provide meticulous skin care.

IMPOPERATE ANUS

Stricture or absence of Anus

• Occurs 1-5 in live births boys more than girls
• Newborn if they observe they see what is going on they check output 24hrs
• Intestinal obstruction

Cleft lip

results from nose elavation Causes: Medication, chemical or vitals/exposures

SPINAL BIFIDA OCLATA

• Defect of the verble bodies the Spinal cord (not visual)
• Defect is not visible -The nurse will let the family know in the diagnosis

MENINGICELE

The spinal is normal. Surgicel correction

LATE SIGNS OF HYDRADOCEPHALIS

• Low LOC
• Bradycardia
• Abnormal breathing Decreased movements