Prematurity Flashcards
What is the definition of prematurity?
Birth before 37 weeks gestational age
Prematurity classification
Late preterm <37 wks
Very preterm <33
Extremely preterm <29
Micropremature <26
What are risks associated with prematurity?
Neurologic complications leading to structural neuroanatomical changes and increased morbidity/mortality
Compromise in brain function
Disruption of futrue development
What is the proxy for gestational age?
Birth weight
What is a common progression of neurologic complications associated with prematurity?
Hypoxic-ischemic encephalopathy (HIE) to
INtraventricular hemorrhage (IVH) to
Periventricular hemorrhagic infarction (PVH) to
Periventricular leukomalacia (PVL)
What are risk factors for premature birth?
Maternal hx of previous preterm birth Multiple birth pregnancy Maternal age <16 and >35 Maternal health problems: diabetes, obesity, HTN, kidney/heart disease, infections during pregnancy Uterus/cervix abnormalities Maternal alcohol, drug, alcohol use Low SES Lack of prenatal care AA ethnicity
Classification of birth weight
Low BW <2,500g (5 lbs, 8 oz)
Very low BW <1,500 g (3 lbs, 5 oz)
Extremely low BW <1000g (2 lbs, 3 oz)
Micropremature <750g (1 lb, 10 oz)
What is the incidence of PM and low BW?
12.3% and 8.2% low BW
Rate steadily declined since 2006, primarily in late preterm births
What is PM survival rate?
80% at 26 wks, 25% will develop severe long-term disabilities (blindness, CP), 50% learning and behavioral problems
96% 28-31 wks
98% 32-33 wks
99% 34-36 wks
What is the current threshold of biological viability?
23 weeks GA
What are causes of PM?
45-50% idiopathic
30% premature rupture of membranes
15-20% medically indicated preterm delivery
What are neurological sequalae of IVH?
Grade i - bleeding in germinal matrix
Grade II - bleeding into ventricles w/o dilation
Grade III - bleeding resulting in v dialtion
Grade IV - large Hem with PHI in parenchyma
What are predictors of functional outcome in PM?
Severity of neurologic complications
Use of steroids
Care center factors, transfer to NICU in first 24 hrs, availability of neonatologist
SES, maternal edu level and mental health, quality of responsive care, environmental stimulation
Male sex
Length of NICU stay
Reduced W and G matter volumes, lg ventricle size
What is the critical period?
First 24 hrs - 50% IVH in first 6-8 hours
What is Cranial ultrasound?
Most common imaging technique in the context of prematurity used to detect neurologic events and abnormalities, useful to detect IVH
What method is used to detect white M abnormalities like PVL?
MRI
What is the purpose of surfactants?
To keep air sacs in the lings open during respiration, naturally produced btw 24-28 wks
What are risks of postnatal steroid use?
Chronic hypoxia, reduced cerebral volume, neurodevelopmental delay
What are basic physiologic functions that should be monitored in neonates?
Body temp, oxygenation and pressure, and cardiac function
What is the purpose of NIDCAP?
To replicate intrauterine environment to the extent possible
What are some assessment measures in infants?
Neonatal behavioral assessment scale
Bayley scales of infant and toddler development-III
Mullen scales of early learning
What are incidence rates of CP in PM?
6% born <1500g
4% 1500-2500
1% >2500
What are neuropsychological findings in PM?
Functional outcomes vary by cohort year
Lower IQ, higher with increasing gestational age
Slower rate of academic problem, mostly in math and written output
Attention - increased rates of ADHD
Slowed processing speed
Lg -problems with fluid verbal skills, comprehension, fluency, pragmatics
VS - particularly vulnerable! due to proximity of PV region to optic rediations
Memory - decreased acquisition and retrieval, reduced hippocampal volumes
EF problems
Sensorimotor deficits are common - dexterity, coordination, visuomotor integration
What are behavioral findings?
Both externalizing and internalizing problems
Poor social skills
Increased rates of anxiety, reduced adaptive skills
Increased prevalence of ASD in extremely preterm and low BW children
What is the age correction?
Age correction if made until 24 months
What is apnea or prematurity?
Unexplained cessation of breathing due to immature respiratory control system
What is bronchopulmonary dysplasia?
Chronic lung disease due to ventilator support or high levels of oxygen for long periods shortly after birth
What is CP?
Group of disorders affecting movements/coordination
Caused by abnormal brain development before birth within 2 years of life
What is germinal matrix?
Highly vascularized region of brain below lateral ventricle
What is IVH?
Hemorrhage due to increased vascular pressure and vessel rupture
What is intrauterine growth restriction?
Poor growth of fetus during pregnancy, mostly associated with insufficient oxygen/nutrition from placenta
What is necrotizing enterocolitis?
Death of intestinal tissue
What is neonatal septicemia?
Severe infection/sepsis cased by pregnancy complications
What is patent ductus arteriosus?
Heart condition resulting in abnormal blood flow between the aorta and pulmonary arteries
What is the definition of small for gestaitonal age?
<10th %ile compared to babies of equal GA
What is PVL?
focal necrotic lesions in hte border end zones of MCA, ACA, and PCA
Increased risk for CP, particularly spastic diplegia
What is retinopathy of PM?
Abnormal development of retina blood vessels
