Prematurity and Intrauterine Growth Retardation Flashcards
What is the weight of infants considered low-birth-weight infants?
<2500 g
Classification of newborns < 1500 g?
Very-low-birth-weight infants
Four factors contributing to premature birth of an infant?
- Maternal illness
- Uterine incompetence
- Fetal disorders
- Placental abnormalities
What are the major causal agents that lead to neonatal problems?
Organ immaturity
What physiologically occurs that results in respiratory distress in premature infants?
Lining of cells in fetal alveoli do not differentiate into type I and type II pneumocytes
What allows alveoli to remain expanded during the respiratory cycle?
type II pneumocytes that produce surfactant
What is the ratio of lecithin to sphingomyelin that indicates that a neonate should survive w/o developing RDS?
2:1
What indicates the best proof of the maturity of fetal lungs?
Presence of phosphatidyl glycerol in the amniotic fluid
What enzyme in absent in an immature liver?
Glucuronyl transferase resulting in neonatal jaundice
What does the Apgar scoreindicate?
Clinical assessment of neonatal maturity performed at 1 and 5 minutes post-delivery
What does neonatal surfactant deficiency result in?
Neonatal Respiratory Distress Syndrome
Describe the general pathogenesis involved with neonatal RDS
- Immature type II pneumocytes
- No surfactant
- Lung epithelium adheres and cells leak plasma contents into alveolar space resulting in further binding of surfactant and respiratory insufficiency
- Lack of ventilation
- Hypoxia and acidosis
- Further dysfunction of type II pneumocytes
What is the name given to the uscopic findings of a neonate with RDS?
Hyaline membrane disease due to alveolar ducts lined by conspicuous eosinophilic fibrin-rich amorphous structures
Clinical signs of RDS?
- Early on, typically fine
- Increased respiratory effort
- > 100 RR
- Cyanosis and flaccidity
- Death by asphyxia
What are some major complications of RDS?
- INtraventricular cerebral hemorrhage
- Persistent patent ductus arteriosus
- Necrotizing enterocolitis
- Bronchopulmonary dysplasia
Hemolytic disease caused by maternal antibodies against fetal erythrocytes?
Erythroblastosis Fetalis
What Rh antibodies typically cause 90% of erythroblastosis fetalsis?
Rh D
What pregnancies are typically affected by mother Rh antigens?
Following the first pregnancy when the mother (Rh-) is sensitized to the Rh+ baby. Following Rh+ babies will be affected.
What is the most severe sequela of erythroblastosis fetalis?
Death in utero
What is the most serious form of erythroblastosis fetalis in liveborn infants?
Hydrops fetalis characterized by severe edema due to CHF caused by severe anemia
Condition associated with severe jaundice and characterized by bile staining of the brain, particularly in the basal ganglia, pontine nuclei and dentate nuclei in the cerebellum
Kernicterus (Bilirubin encephalopathy)
What has become the main cause of hemolytic disease in newborns?
ABO incompatibility
What is the name of the condition in which edema of the scalp occurs caused by trauma to the head during passage through the birth canal?
Caput succedaneum
Subperiosteal hemorrhage of a single cranial bone?
Cephalohematoma
