Ch 10 Flashcards
What is a congenital malformation?
Primary error of morphogenesis - can be single gene, usually is multifactorial
Eg congenital heart defect, anencephaly
What is a congenital disruption?
Secondary destruction of organ that was previously normal . Not heritable. Eg amniotic band disrupting morphogenesis in foetus.
What is a deformation?
Extrinsic cause leading to disturbance to normal development eg uterine constriction
What is a sequence?
A cascade of abnormalities triggered by one initiating aberration eg oligohydramnios (Potter Sequence)–> fetal compression –> altered facies, breech, pulmonary hypoplasia
What is malformation syndrome?
A constellation of congenital anomalies secondary to a single agent eg viral infection
What is agenesis?
Complete absence of organ and associated primordium
What is aplasia?
Absence of organ due to failure of growth primordium
What are the 2 phases on intrauterine development?
- Embryonic period (first 9 weeks)
- Fetal period (finishes after birth)
What is the ‘early embryonic’ period?
First 3 weeks after fertilization
What is the teratogenesis period (foetus most susceptible to major congenital abnormalities)?
3-9 weeks
What is cyclopramine and what effects does it have to the foetus?
Plant teratogen found in corn lily. Inhibits hedgehog signalling and leads to cyclopia/holoproencephaly
What is the effect of valproic acid on the developing foetus?
Disrupts Homeobix (HOX) signalling. Involved in patterning of limbs: vertebrae, craniofacial abnormalities
What is the effect of excessive Vitamin A (Retinol/Retinoid acid) on developing foetus?
Deregulated TGFB.
CNS, cardiac, craniofacial/cleft lip/palate
What is an example of transcervical infection to fetus?
Herpes simplex II
How does the foetus acquire an infection from cervix/vagina?
1.Through birth canal
2. Inhales amniotic fluid into lung preterm
What is an example of transplacental/hematologic infection?
Toxoplasmosis, Treponema, Listeria, malaria
What are the TORCH infections?
Toxo
Other (Syphilis, varicella, Parvo B19)
Rubella
Cytomegalovirus
Herpes
What are the clinical manifestations of TORCH infections?
Fever
Encephalitis
Chorioretinitis
Hepatosplenomegaly
Pneumonitis
Myocarditis
Haemolytic anemia
Haemorrhagic skin
Growth restriction later in life
What is ‘Fifths disease’ or Erythema infectiosum?
Parvovirus B19 infection
Bone marrow of foetus. Dx
Parvo B19 infection - viral inclusion rim to erythroid progenitors
What are the usual causes of assymetric growth restriction?
Placental
Maternal
(Infections, genetic or erythroblastosis causes SYMMETRIC restriction)
What are the risk factors of SIDS (Sudden Infant death syndrome)?
Age of child (1mo-1yr)
Low SES
Gender (Male)
Absence of abnormal anatomy
What histologic finding would be seen in CF?
Mucous plugging
What is Hyaline membrane disease?
Insufficient Type II alveolar cell surfactant production
Deficiency in galactosemia?
Galactose-1-phosphate uridyl transferase
What findings in galactosemia?
Liver damage (pancreas is normal)
What makes a neuroblastoma worse prognosis?
N-myc amplification
Presentation of a neuroblastoma in child?
Fever
Weightloss
Abdominal mass (on adrenals)
Urine homovanillic acid
Lymphangioma
Teratoma (benign)
How does oligohydramnios cause respiratory distress?
Lung hypoplasia (small)
When does Hyaline membrane disease occur?
Birth before 35 weeks
What tests on amniotic fluid can help assess lung maturity? 3
Lamellar body counts
Lecithin-sphingomyelin ratio
Florescence polarization
Which infection can lead to heart defects?
Rubella
What are the complications of erythroblastosis?
Anaemia
Heart failure
SYMMETRIC growth restriction
When do type II pneumocytes differentiate?
Week 26
What 2 compounds reduce surfactant surface tension?
Phosphatidylcholine and phosphotidylglycerol
What maternal risk factor can increase risk of hyaline membrane disease?
Gestational diabetes
Port wine stain is composed of
Capillaries
Large renal tumours (Wilms) are associated with which syndrome
Beckwidth-Widemann
Chorioamnionitis is likely caused by
Bacterial (usually strep)
Complications associated with galactosemia?
E.coil septicemia (unknown reason)
Cataracts
