Prematurity Flashcards
What is often used as a proxy for gestational age due to the high correlation between the two and the difficulty of precisely determining gestational age.
Birth weight
Prematurity and Low Birth Weight definitions
Most common neurological complications of preterm birth
Periventricular hemorrhagic infarction (PVHI)
- infarction that is most frequently a complication of a large IVH
- results in asymmetric necrosis of the periventricular white matter
periventricular leukomalacia (PVL) - which can be considered a Hypoxic-ischemic encephalopathy (HIE)
- Focal necrotic lesions occur in the border end zones of MCA, PCA, ACA
- Increases the risk for CP, specifically spastic diplegia (stiff legs). More extensive PVL can include involvement of the upper extremities as well.
germinal matrix
a highly vascularized region of the developing brain located underneath the lateral ventricles, and hemorrhage in this area (i.e., germinal matrix hemorrhage, GMH) is a devastating neurological disease in premature infants that results in substantial mortality and morbidity.
it is located in a vascular watershed zone
by 36 weeks gestational age the germinal matrix has largely disappeared reducing risk for hemorrhage in this area
Intraventricular Hemorrhage Grade
Risk Factors for Premature Birth
- Maternal history of previous preterm birth
- Short spacing between pregnancies
- Multiple birth pregnancy
- Younger (<16) and older (>35) maternal age
- Maternal health problems (high blood pressure, diabetes, obesity)
- Maternal alcohol, drug, or cigarette use
- Low SES
What accounts for the vast majority of preterm/low birthweight births.
Multiple births (twin and triplet/+)
The current threshold of biological viability is considered to be…?
- 23 weeks gestational age in high-income countries
- 34 weeks in low- and lower middle-income countries.
When does IVH occur?
- 50% of all IVH occurring in the first 6 to 8 hours of life
- 95% occurring within the first 4 to 5 days.
Complications in preterm infants
- hypoxic/ischemic neurological events
- Bronchopulmonary dysplasia (BPD)/chronic lung disease
- apnea of prematurity
necrotizing enterocolitis (NEC) - condition inflames intestinal tissue, causing it to die d/t bacterial leakage into the belly or bloodstream (25% mortality rate) - retinopathy of prematurity,
- septicemia/sepsis
- patent ductus arteriosus (PDA)
- respiratory distress syndrome (seen in infants 28 weeks or earlier, d/t lack of surfactant
- pulmonary hypertension
Common neuropsychological sequelae among preterm children
- attention/EF
- processing speed
- visuospatial skills (possibly due to injury proximity to optic radiations and dorsal ventral stream)
- general memory recall
- sensorimotor (VMI, dexterity)
- behavioral concerns (hyperactivity, poor social skills)
How is gestational age calculated?
typically calculated from the first day of the last menstrual period.
Hypoxic-ischemic encephalopathy (HIE)
term used to describe encephalopathy caused by a reduction in cerebral oxygenation and blood flow.
the specific cause or contribution of each risk factor of preterm baby to HIE is often uncertain.
Intrauterine growth restriction (IUGR)
Refers to poor growth of a fetus during pregnancy - when the developing fetus’s weight falls below the 10th %ile compared to other babies of equal gestational age
most commonly it is associated with a fetus not receiving enough oxygen and nutrition from the placenta during pregnancy
IUGR is associated with abnormal development of frontal brain regions
Intraventricular hemorrhage (IVH)
Refers to increased vascular pressure and consequent vessel rupture and hemorrhage.
Earlier onset of IVH is associated with more severe grade.
90% of all IVH occur in the first four days of life
Even in infants with the lowest grades of IVH, increased incidence of learning disability is apparent.
