Prematurity Module AnS 536 Spring 2015. What is Prematurity? Prematurity is defined as less than 37...
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Transcript of Prematurity Module AnS 536 Spring 2015. What is Prematurity? Prematurity is defined as less than 37...
What is Prematurity?
Prematurity is defined as less than 37 weeks of gestation in humans
Prior to 32 weeks is considered a very premature birth
Less than 28 weeks is extremely premature
Preterm Labor Occurs prior to expected delivery date Occurs for a variety of reasons
Prelabor rupture of membranes Can lead to amnionitis
Methods to prevent labor Stop /delay onset of pre-mature births Do not guarantee a healthy infant
Planned interventions to terminate pregnancy Serious maternal illness Problems affecting fetal well being or growth
Preterm Labor Preterm labor prevention:
Social measures Ad campaigns increasing awareness
Smoking Sexually transmitted diseases
Physical measures At home uterine-activity monitoring Bed rest Cervical assessment
Surgical measures Cervical cerclage
Preterm Labor
Preterm labor prevention cont…Pharmacological agents
Betamimetic drugs Stop uterine contractions in active labor Most widely used among other labor-inhibiting agents
Inhibitors of prostaglandin synthesis Strong and practical use in preventing labor
Antibiotics Some use in preventing early labor in women with
bacterial vaginosus
Preterm Labor Types of preterm births
Antepartum death Lethal malformations
Fetal outcome cannot be changed, vitality of mother is important
Multiple pregnancies 50% of all multiple pregnancies result in premature delivery
Elective deliveries Maternal and/or fetal pathology
Preclampsia Antepartum hemorrhage Intra-uterine growth restriction
Antepartum death and lethal malformations 10-15% of all premature births Almost 50% of total perinatal mortality This form is unsavable Infant dies before labor or has
malformations that are incompatible with life Maternal well-being is a large factor Ethical problems come in to play
Multiple Pregnancy
Almost half of multiple births occur prematurely
Multiple births are 15 times more likely to be associated with premature delivery
Multiple births make up 20% of all premature cases
Elective Delivery
Planned obstetric decision Complications during pregnancy within the
mother or the fetus Not necessarily premature infants
Maternal and Fetal Pathology
Eclampsia Antepartum hemorrhage Intra-uterine growth restriction Spontaneous preterm labor
Route for Delivery
Main decision for premature infants Vaginal or Cesarean Section Breech much more common in preterm Safer for premature infants to use C-section
Mostly planned deliveries Premature baby is more susceptible to
compress from the pelvic region than a term baby They have a softer skull
Preterm Birth
Physiological consequences Infant’s body system are not prepared to
function on their ownNumerous conditions that result from
prematurity can be treated Depending upon extent of prematurity,
morbidity rate may be great
Preterm Birth Preterm birth is the leading cause of neonatal mortality
Lack of development of body systems is underlying cause
Concerns: Increased morbidity and mortality Intraventricular hemorrhage (IVH)Periventricular leukomalacia (PVL)Cerebral palsyNecrotizing enterocolitis (NEC)Retinopathy of prematurity (ROP)Respiratory distress syndrome (RDS)
Preterm Birth Complications
Respiratory distress syndrome Affects over 50% of premature infants One of leading cause or mortality and
morbidity Ventilator needed in some cases Use different techniques to speed up
pulmonary maturation or assist lung function
Preterm Birth Complications
Corticosteroids betamethasone and dexamethasone
Reduce risk of RDS by 40-60% Speeds up lung maturation Max effect more than 24 hr prior to birth
within 7 days of administration Risks to corticosteroids
Increased susceptibility to infection
Renal System
Decreased ability to maintain blood pressure
Difficult time regulating electrolyte and water balance
Neurological
Developmentally behind slightly Intraventricular hemorrhage
Blood vessels of brain not fully developed Premature infants at a much higher risk Increase risk if other problems No prevention
Hydrocephalus Fluid accumulation in the brain
Neurological
Periventricular leukomalaciaContributing factors:
Premature infant brains very fragile Lack of oxygen Early rupture of fetal membranes Infection inside the uterus
No treatment for this condition
Thermoregulation
Tend to lose body heat rapidly Less stored fat At high risk to hypothermia
Leads to breathing problems and low blood glucose
Use available energy for heatHypoglycemiaDecreased stores of glycogen
Gastrointestinal and Metabolism
Immature systems Necrotizing enterocolitis
Cells in bowel are injured Infants fed only breast milk have lower risk
Spontaneous intestinal perforation
Immunity
Increased susceptibility to infection through childhood
Risk of bacterial infectionProlonged intensive careNICU environment
Immunoglobulin G deficiency at birth
Immunity cont.
Slower development of innate immune defense
Prematurity affects all aspects of immunity Immune signaling Link between adaptive and innate immunity
Limited neutrophil precursor pool Neutropenia
Increase bacterial infections
Long Term
Cerebral palsy 40-50% of patients were born prematurely Affects movement and muscle tone Results from CNS damage
Poor circulation Insufficient oxygen and nutrient supply Neural infection
Impaired cognitive skills Lag behind full-term babies in mental development More likely to have a learning disability
Long Term Cont.
Vision problems Retinopathy of prematurity
Blood vessels swell and overgrow in the light sensitive layer of the nerves of the retina
Retinal scarring Retinal detachment
Possible blindness
Hearing problems Increased risk of hearing loss
Long term cont.
Dental problems Delayed tooth eruption Tooth discoloration Improper alignment of teeth
Behavioral and psychological problems More likely to develop problems Attention deficit hyperactivity disorder (ADHD) Depression or anxiety Interaction issues
Long term cont.
Chronic health issues InfectionsAsthmaFeeding problemsSudden infant death syndrome
Possible risk of diabetes and cardiovascular disease
Preterm Birth Cerebral palsy
Condition where infants are unable to control muscle movement
Muscles become tight and uncontrolled No treatment for this condition
Necrotizing enterocolitis Occurs 3 to 7 days after onset of feeding Premature infants react abnormally to diet Bowels become inflamed and spontaneously necrose Treatment:
Surgical treatment if bowel is perforated Feedings are withdrawn Contents of stomach are suctioned out