Transcript Prematurity - Johns Hopkins University

Prematurity
Born too small
Born too soon
Development of Young Children with Disabilities
#872.514 (61)
Carol Ann Heath
What is Prematurity
Preterm delivery is defined as birth occurring
from 20 weeks to 36 completed weeks of
gestation
Born at/or before the 36th week of gestation (one
month before the estimated due date)
Small for Gestational Age (SGA)
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Newborn whose weight is below the 10th
percentile for gestational age
Sometimes called dysmature, light for dates, or
small for dates
Can be full term or premature
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Low birth weight (LBW) - infant born weighing
less than 2,500 grams
Very low birth weight (VLBW) - infant born
weighing less than 1,500 grams
Extremely low birth weight - infants weighing
less than 1000 grams
Micropremies – infants weighing less than 800
grams
Incidence
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Occurs in 5 to 10% of all pregnancies
Accounts for 60 to 75% of infant morbidity and
mortality
Half occurs idiopathically in women with no
known risk factors
Health care costs increased by billions
What Happens? Toronto Study
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330,000 live births
568 born between 23 to 26 weeks gestation
without disabilities at age 2 yr:
one born at 23 weeks
three at 24 weeks
- all required months in neonatal intensive care
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What are the Risk Factors?
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Socioeconomic factors:
teenagers
women over 35 yr.
women underweight at conception
obese women
smokers
alcohol and substance abusers
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Long commutes
Work involving extended periods of standing
Stress:
poor social support
abusive relationships
Nutritional deprivation
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Inadequate prenatal care
30% more likely to have preemies than those
with access to care
Poor pregnancy history
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History of multiple abortions (spontaneous &
elective)
Short pregnancy intervals (< one year )
Medical Factors
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Diabetes
Hypertension
Toxemia
Lupus
Daughters of women who took DES
Women with a cone biopsy
Abdominal surgery
2nd & 3rd trimester bleeding
Causes
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Infection
Abdominal trauma
Placenta previa or abruptio
Multiple gestation
Pre-term rupture of membranes
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Uterine or fetal anomalies
Uterine fibroids
Cervical incompetence
Maternal Pyelonephritis (kidney infection)
Chronic maternal illness
Preeclampsia
Preterm Birth
Derives from one of three mechanisms:
- preterm labor
- preterm premature rupture of membranes
- medical intervention (induced)
Treatment of Preterm Labor
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Bed rest & hydration
Tocolytics (beta-adrenergic blocking agents)
Corticosteroids
Home uterine monitoring
Signs of Preterm Labor
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Contractions
Abdominal, low back pain
Change in vaginal discharge
Pelvic pressure
Intestinal cramping
Characteristics of Premature Infant
Physical Characteristics
 Presence of body hair
 Reddish skin color
 Absence of skin creases, ear cartilage, and
breast buds
Neurological Characteristics
 Very flopping <28 weeks
 Double jointed
 Underdeveloped reflexes at birth
 Behaviorally disorganized
 Sleep mostly
Complications
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Respiratory distress syndrome (RDS)
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Bronchopulmonary dysplasia (BPD)
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Intracerebral insults
Complications
cont’d
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Patent ductus arteriosus
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Apnea and bradycardia
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Sudden infant death syndrome
Complications
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Necrotizing enterocolitis
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Gastroesophgeal reflux
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Retinopathy
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Infections
cont’d
Outcomes of LBW
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1960: survival rate for infants
1,500 to 2,500 grams - 50%
1,000 to 1,500 grams - <30%
<1,000 grams - 10%
1990: survival rate for infants
more than 90%
750 to 1,000 grams - 75%
500 to 750 grams - 35%
1995: survival rate for infants
< 500 grams - rare
500 to 749 grams - 47%
750 to 999 grams - 80%
>1000 grams - 90%
>1500 grams - 95%
Neurodevelopmental Outcomes
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1960
<1,500 grams - <10% survival w/o disability
1980
incidence of developmental disability for LBW <20%
1990s
-severe disability 6xs more likely in extremely LBW
infants than full-term
-learning disabilities/ADHD 3xs more likely in VLBW
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Microcephaly (head circumference <3rd
percentile
Higher incidence of school failure
Greater % in special education
Spastic cerebral palsy (most common)
Common Medical Complications
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Respiratory Distress Syndrome
(hyaline membrane disease)
Persistent Fetal Circulation
Retinopathy of Prematurity
Intraventricular Hemorrhage
Periventricular Leukomalacia
Correcting for Prematurity
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Classic approach- completely correct for
gestational age until the child reaches 2 years
Research indicates can miss vision & hearing
impairments
Newer approach- assess the rate of
development
Academic in Later Life
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VLBW infants fare worse in reading & writing
development (10 European Conference on Developmental Psychology)
th
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An assessment of 7,505 children showed lower
IQ on average at 5 years of age
Early Childhood Longitudinal Kindergarten Cohort (ECLS-K), we assess the
relationship between low birthweight (LBW 15001-2500g) and very low birthweight
status (VLBW <1500) on a variety of childhood developmental outcomes including
(1) academic ratings scales, (2) social ratings scales, (3) motor skills, (4) grade
failure, (5) self-reported scales and (6) objective math and reading scores.
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Using school and teacher fixed effects models for teacher assessments,
population-average logistic regression models for risk of grade retention, and
piecewise multilevel growth models for math and reading test scores over time we
found the following: (1) At kindergarten entry LBW and VLBW children are rated
lower on academic rating scales, but these scores were no longer significant after
controlling for background characteristics. (2) VLBW children displayed
disadvantages in Social Rating Scales, especially in approaches to learning. (3)
LBW and VLBW children have significantly lower levels of motor skills and (4) after
controlling for all covariates, there is no evidence that LBW children are more likely
to repeat grades. Finally, (5) at kindergarten entry, LBW show significantly lower
math scores, although there are no differences in growth rates, in either math or
reading.
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The evidence from this study suggests that although LBW children tend to have
lower performance, most of the difference between those children and normal
children are due to other associated disparities.
Source: Goosby & Cheadle, 2009
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Differences at 8.5 Years
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Only 51.5% of VLBW were at grade level
compared with 91.2% of control group
22.8% of VLBW in special schools compared
with 1.5% of control group
Nearly 30% of VLBW had reading problems
Nearly 40% of VLBW had writing problems