Ch 17 Prematurity

Question 1

 Prematurity is defined as

Answer 1

Birth that occurs before 37 weeks

Immaturity of body systems

Question 2

What is often used as a proxy for gestational age?

Answer 2

Birthweight

Question 3

Birth weight classifications

Answer 3

Low birth weight 5lb 8oz
Very low birth weight 3lbs 5oz
Extremely low birth weight 2lbs 3oz
Micropremature 1lb 10oz

Question 4

Gestational age classifications

Answer 4

Late preterm birth <37
Very preterm <33
Extremely preterm <29
Micropremature <26

Question 5

Pre term infants are at risk for what kinds of neurological complications?

Answer 5

Periventricular hemorrhagic infarction (PVHI)
Periventricular leukomalacia (PVL)

Question 6

Describe sequence of PVHI

Answer 6

sequence of events begin with reductions in cerebral oxygen and blood flow (hypoxia ischemia)

result in intraventricular hemorrhage, and then PVHI

Question 7

Other neurological complications in premature infants?

Answer 7

Post hemorrhagic hydrocephalus
Focalized neuronal injury
Cerebral ischemic lesions

Question 8

Another kind of neurological complications in preterm infants?

Answer 8

Hypoxic ischemic encephalopathy with corresponding presentation such as:
poor Apgar scores
cord blood metabolic acidosis
need for resuscitation

Question 9

How many grades of intraventricular hemorrhage are there

Answer 9

4

Question 10

Grade I of IVH

Answer 10

Bleeding into germinal matrix

Question 11

Grade II of IVH

Answer 11

Bleeding into ventricles, but no ventricular dilation

Question 12

Grade III of IVH

Answer 12

Bleeding resulting in ventricular dilation

Question 13

Grade IV of IVH

Answer 13

Large hemorrhage with PVHI in parenchyma

Question 14

Risk factors for premature birth

Answer 14

Maternal hx of previous preterm birth
Short spacing between pregnancies multiple birth pregnancy
Maternal age younger than 16 older than 35
Maternal health problems (diabetes, obesity, HBP, kidney disease, heart disease, infections, stress)
Uterus or cervix abnormality
Alcohol, drugs, cigarette use
Low SES
Lack of prenatal care
Black

Question 15

% of preterm births in US

Answer 15

10%

• 7% late preterm <37 weeks
• 3% <33 weeks

Question 16

% of low birth weight in the US

Answer 16

8% low BW

1% very low BW

Question 17

What factor accounts for the majority of preterm and low birth weight?

Answer 17

Multiple births

Question 18

Infant mortality rate in the United States

Answer 18

6 per 1000 births

Question 19

Second leading cause of death in infants under 12 months old

Answer 19

Premature birth

Question 20

% of for infant deaths caused by premature birth

Answer 20

1/3

Question 21

Preterm birth rate has been increasing or decreasing over recent years in the United States?

Answer 21

increasing

Question 22

Which group has the highest rate of preterm birth, low birth weight and infant mortality?

Answer 22

Black

Question 23

% of <25 weeks babies survive in high income countries

Answer 23

1/3

Question 24

25-27 weeks baby survival rate in high income countries

Answer 24

80%

Question 25

28-31 weeks baby survival rate in high income countries

Answer 25

96%

Question 26

32-33 weeks baby survival rate in high income countries

Answer 26

98%

Question 27

34-36 weeks baby survival rate in high income countries

Answer 27

>99%, but 4x more likely to die than full term

Question 28

biological viability for high income countries

Answer 28

23 weeks

Question 29

biological viability for low/middle income countries

Answer 29

34 weeks

Question 30

leading cause of death worldwide

Answer 30

premature birth

Question 31

determinants of severity

Answer 31

``` birth weight use of prenatal and postnatal steroids gestational age in weeks neurological complications (grades III, IV IVH) access to NICU NICU stay familial/environmental factors (SES, education, maternal health) male vs female baby (male worse outcome) reduced gray and white matter volumes larger ventricular size ```

Question 32

recovery course

Answer 32

first 8 hours are critical 50% of IVH occur in the first 6 to 8 hours of life 95% occur within first 4-5 days

Question 33

assessment methods

Answer 33

ultrasound - GOOD detection of IVH, severe white matter injury (NOT sensitive to certain White matter injuries) MRI - monitor brain dev, detect PVI and other injuries CT, EEG

Question 34

General Movement Assessment (GMA)

Answer 34

for kids younger than 5 months combined with neonatal MRI to predict CP assess spontaneous movements in children preterm

Question 35

Hammersmith Infant Neurological Exam (HINE)

Answer 35

for kids > 5 months | combined with neonatal MRI to predict CP

Question 36

Treatment

Answer 36

magnesium sulfate - assists with neurogeneration synthetic surfactant - keep air sacs in lungs open during respiration hypothermia and hyperbaric chambers - decrease incidence of HIE inhaled nitric oxide - reduce incidence of bronchopulmonary dysplasia (BD) postnatal steroid - prevent and treat respiratory complications CONTROVERSIAL!

Question 37

complications in pre term

Answer 37

``` hypoxic ischemic neurological events chronic lung disease apnea of prematurity necrotizing enterocolitis (NEC) retinopathy of prematurity septicemia patentductus arteriosus respiratory distress syndrome pulmonary hypertension bronchopulmonary dysplasia ```

Question 38

NP results for pre terms

Answer 38

IQ - variable but may be lower. increases with gestational age. Academic functions - usually more challenges, special education, grade retention attention - increased ADHD processing speed - slow speed is common (white matter pathology in preterms) language - semantic, crystallized language is ok; comprehension, fluency is worse; naming is hard; overall language progresses visuospatial - usually bad because periventricular regions close to optic radiations and dorsal stream dysfunction memory - slow acquisition, deficits recall; spatial memory deficits for micropremies; reduction in hippocampal volume executive functions - working memory, planning, set shifting, vigilance, organization problems sensorimotor - common deficits emotions and personality - more problems than peers SVT, PVT - not studied

Question 39

germinal matrix

Answer 39

most common location of IVH in preterm highly vascularized and highly cellular below lining of lateral ventricle cells migrate here during development, diminishes gradually and disappeared by 36 weeks

Question 40

IUGR

Answer 40

poor fetus growth during pregnancy fetus' weight falls below 10th percentile usually because fetus not getting enough O2 and nutrition from the placenta abnormal development frontal brain region lower IQ and NP impairment

Question 41

Bronchopulmonary dysplasia (BPD)

Answer 41

chronic lung disease tx by mechanical ventilator and supplemental O2 cog impairment in severe BPD

Question 42

IVH

Answer 42

cog impairment and learning disability increases with severity of IVH (by grade) can be detected by ultrasound

Question 43

necrotizing enterocolitis

Answer 43

cell death of intestinal tissue when lining of intestinal wall dies and tissues fall off offer most in preterm or sick infants poor prognosis, 25% of cases die as a result

Question 44

patent ductus arteriosus (PDA)

Answer 44

heart condition in which ductus arteriosus of the heart does not close abnormal blood flow between aorta and pulmonary arteries

Question 45

PVHI

Answer 45

venous infarction complication of IVH obstructs terminal veins, causes PVI and HVI results in necrosis of periventricular white matter

Question 46

PVL

Answer 46

ischemic injury to white matter surrounding lateral ventricles lesions occur near MCA, PCA, ACA abnormalities in the function of corticospinal tract increases risk for CP