Premature Neonate Health Quiz

Preterm Infant Definition

• Preterm infant is defined as a baby born alive before 37 weeks of pregnancy are completed.
• Full term gestation is 40 weeks (range 37 to 42 weeks).
• A preterm infant is traditionally defined as a live-born infant born before the end of week 37 of gestation.

Factors to Determine Gestational Age

• Neonatal assessment (Ballard Scoring)
• Inspection for sole creases, skull firmness, ear cartilage and neurologic development.
• The mother's report of her last menstrual period.
• Sonographic estimation of age.
• All of these factors are beneficial for determining gestational age.

Newborn Evaluation

• Newborns should be evaluated immediately after birth to determine their weight, height, head circumference, and gestational age.
• This evaluation helps determine their immediate healthcare needs and anticipates possible future problems.
• Preterm birth occurs in approximately 11% of live births worldwide, with the United States having one of the highest rates.

Preterm Infant Needs

• All preterm infants need intensive care from the moment of birth to give them their best chance of survival without neurologic aftereffects.
• Preterm infants are more prone to hypoglycemia, intracranial hemorrhage, and respiratory distress syndrome (RDS).
• Limited glycogen and fat stores and the inability to generate new glucose are common issues.
• Blood vessels are not fully developed and are extremely fragile.
• Lack of lung surfactant forms until the 34th week of pregnancy.

Categories of Preterm Birth

• Late Preterm: Born between 24 and 34 weeks.
• Early Preterm: Born between 34 and 37 weeks.
• Moderate Premature: Less than 37 weeks.
• Very Premature: Less than 34 weeks.
• Extremely Premature: Less than 32 weeks.
• Extremely Premature: Less than 28 weeks.

Non-Premature Infant Categories

• Early Term: 37 to 38 6/7 weeks.
• Full Term: 39 to 40 6/7 weeks.
• Late Term: 41 to 41 6/7 weeks.
• Post Term: ≤42 weeks.

Etiology of Premature Labor

• The exact cause of premature labor and early birth is unknown.
• Possible causes include premature rupture of membranes, infections, and placental abruption.
• Gestational age is a major determinant of neonatal death rates.
• Preterm infant deaths account for 80-90% of infant mortality in the first year of life.

Elective Preterm Delivery

• The American College of Obstetricians and Gynecologists (ACOG) recommends late preterm delivery in multiple gestations with complications, preeclampsia, placenta previa, placenta accreta, and premature rupture of membranes to prevent further complications.
• Late preterm deliveries can facilitate the management of severe maternal or fetal issues.

Spontaneous Preterm Delivery

• Patients with spontaneous preterm delivery might not have an obvious immediate trigger such as intra-amniotic infection, infectious disease in pregnancy, and placental abruption.
• Toxoplasmosis, caused by Toxoplasma gondii, can lead to miscarriage or stillbirth.

Risk Factors

• Past Obstetric History: Prior premature births, prior multiple pregnancies, and prior multiple abortions are significant risk factors.
• Current Pregnancy-Related Factors: In-vitro fertilization (IVF), poor nutrition during (or before) gestation, cigarette smoking, and lack of prenatal care.
• Socioeconomic Factors: Low socioeconomic status and less formal education of mothers correlate with preterm delivery.

Signs and Symptoms

• Head: Disproportionately large head (23 cm greater than chest size).
• Skin: Often unusually ruddy, translucent, thin, and pink with visible underlying veins. May have little subcutaneous fat.
• Lungs: Lanugo (fine hair), covering the back, forearms, forehead, and sides of face.
• Delivery: Delivered after 28 weeks gestation; normally covered in vernix caseosa.
• Ear Cartilage: Small ear cartilage or flattened pinna.
• Extremities: Extremities are not held in flexed position.
• Feet: Flat soles for infants at 28 weeks gestation. Only anterior crease present at 33 weeks gestation.

Signs and Symptoms (Continued)

• Eyes: Difficulty eliciting pupillary reaction. Hazy vitreous humor. Varying degrees of myopia due to shallow eye globe.
• Reflexes: Spontaneous or provoked muscle movements are important. Coordination of swallowing and breathing may be absent in newborns ≤33 weeks gestation. Deep tendon reflexes are diminished.
• Neurological: Neurological function may be immature. Neonates may demonstrate less activity, weak cry, and high-pitched cries.
• Other: Undescended testes. Female labia minor not completely covered.

Potential Complications

• Anemia of prematurity.
• Acute bilirubin encephalopathy.
• Persistent patent ductus arteriosus.
• Periventricular hemorrhage.

Anemia of Prematurity

• Prematurity can cause immaturity of the hematopoietic system, leading to reduced red blood cells (low levels of Vit. E)
• This contributes to anemia, characterized by pale, lethargic, and anorectic presentations.
• Delaring cord clamping to allow additional blood transfer from placenta to infant is a preventive measure.

Acute Bilirubin Encephalopathy

• Excessive red blood cell breakdown at birth leads to high concentrations of indirect bilirubin in the bloodstream.
• Jaundice occurs.
• Preventative measures include phototherapy.
• Severe cases could lead to brain cell destruction.
• Exchange transfusion is another preventative measure.

Persistent Patent Ductus Arteriosus

• Lack of surfactant leads to difficulty moving blood from pulmonary artery to lungs for premature infants.
• This creates pulmonary artery hypertension.
• The ductus arteriosus (connection between pulmonary artery and aorta) fails to close, resulting in abnormal blood flow.
• Preventive measures include intravenous therapy, carefully monitoring urine output and bleeding.

Periventricular Hemorrhage

• Immature cerebral vascular development with fragile capillaries and rapid changes in cerebral blood pressure can lead to bleeding into the tissue around the ventricles (periventricular hemorrhage).
• The prognosis of infants with grade 1 or 2 periventricular hemorrhage is usually positive.
• Grade 3 or 4 bleeds require careful monitoring.
• Brain anoxia may occur distant to bleeding site.
• Ultrasonography and other imaging methods are crucial for detection.
• This complication most often occurs in very low birthweight (VLBW) infants with birth weights less than 1500 grams.

Additional Information

• Specific timing for cranial ultrasound varies by hospital and agency.
• Time for performing and scheduling cranial ultrasound will differ depending on whether the baby is considered high risk or normal.
• Various factors influence when cranial ultrasounds are performed for premature neonates.