Birth and Development

Question 1

Definition and classification of prematurity

Answer 1

Viable at 23 weeks gestation
Preterm at <37 weeks

Late Preterm = <37 weeks
Very preterm= <33 weeks
Extremely preterm = <29 weeks
Micropreterm = <26 weeks

Low birth weight = <2500 g or <5 lbs 8 oz
Very low birth weight = <1500 g or <3 lbs 5 oz
Extremely low birth weight = <1000 g or <2 lbs 3 oz
Micro birth weight = <750 g or <1lb 10 oz

Question 2

Neuropathology of prematurity

Answer 2

Hypoxic-ischemic encephalopathy
Periventricular leukomalacia
Intraventricular hemorrhage
Periventricular hemorrhagic infarction

Question 3

Risk factors for prematurity

Answer 3

Maternal age <16 years of >35 years
African American
Low SES
No prenatal care 
Obesity, diabetes, and high blood pressure
Multiple births
Structural damage to reproductive organs (uterus) 
Infections during pregnancy
Maternal substance use

Question 4

Incidence and prevalence rates of prematurity

Answer 4

Occurs in 6% of singletons, 57% of twins, and 96% of triplets
More common in boys but prognosis does not differ
About half are idiopathic and 30% due to rupture

Question 5

Determinants of severe outcomes in prematurity

Answer 5

Intraventricular hemorrhage (grade I - IV)
Grade I: bleed confined to the germinal matrix
Grade II: bleed in the ventricles without dialation
Grade III: bleed in the ventricles with dialation
Grade IV: large hemorrhage with intraventricular infarcts in the parancyma
Low SES and low maternal education
Prenatal and postnatal steroid treatment
Birth in hospital with a NICU or transfer within 24 hours
Familial environment
Length of NICU stay and growth velocity
Intrauterine growth restriction (IUGR)
Small for gestational age (SGA)

Question 6

Presentation

Answer 6

Preterm babies present with HIE, retinopathy of prematurity, apnea of prematurity, sensorineural hearing loss, patent ductus ateriosus, chronic lung disease, respiratory distress syndrome, and necrotizing enterocolitis

Question 7

Recovery and course for prematurity

Answer 7

Outcomes are variable but first hours are critical
Half of IVH occurs in first –8 hours
95% occurs in the first 4-5 days

Question 8

Neuropsychological outcomes in prematurity

Answer 8

Language: crystallized verbal IQ is stable - deficits in pragmatics, comprehension, and verbal fluency
Executive functions and attention deficient (high rate of ADHD)
Processing speed commonly deficient due to white matter damage
Motor and sensory deficits common (coordination, motor persistence and overflow, hearing loss)
Visuospatial damage due to location of PVL (optic radiation and dorsal stream)
Emotions: anxiety common - autism higher rate in VLBW and EPT
Internalizing and externalizing deficits are common as well as social deficits
Memory: difficulty with acquisition, retention, and recall (reduced hippocampal volume)
Academics: learning disorders are common
Activities of daily living: often have deficits in this area
IQ can be average but still lower than the norm

Question 9

Treatments for prematurity

Answer 9

Hypothermia and hypobaric chamber to reduce risk of HIE
Steroids to help lungs develop
Inhalation of Nitric Oxide to treat chronic lung disease
PDA ligation for PDA
Magnesium sulfate prophylactically to reduce risk of thrombotic event
Surfactant to keep the air sacs open during respiration

Question 10

What is retinopathy of prematurity (ROP)

Answer 10

Blood vessels in the retina of the eye develop abnormally