Birth Defects Flashcards
Compare malformations, deformations, and disruptions
Which usually occurs earliest?
Malformations - due to underlying genetic (instrinsic) defect; occurs early in fetal development
Deformation - due to mechanical force (extrinsic problem)
Disruption - destruction of normally developing tissue
Define a sequence
Sequence = multiple phenotypic traits resulting from a cascade of events
(eg. 5 traits all occur in a cascade, instead of one defect producing 5 traits independently)
What is the underlying problem in Potter’s sequence.
Name 3 symptoms and why they occur
Oligohydramnios (due to renal dysfunction)
- Compression of fetus -> skeletal and facial abnormalities
- Lack of amniotic fluid -> pulmonary hypoplasia
How does fetal alcohol syndrome cause deformities?
Alcohol interferes with cell migration
What is primary defect in Pierre Robin Sequence?
Name 2 complications and why they occur
Pierre Robin = Hypoplasia of the mandible
Tongue is posterior -> Cleft palate, airway obstruction
What is the underlying defect in DiGeorge Syndrome? (2)
22q11 deletion
Abnormal development of 3rd and 4th pharyngeal pouches (endoderm)
Name 2 sequela of isotretinoin exposure.
What genetic syndrome does this mimic?
Cleft palate and tetrology of fallot (Vitamin A excess)
Similar to diGeorge
Define developmental fields
Give one example
Developmental fields = Bmbryonic structures that develop as a unit due to shared gene pathways, shared location, or shared timing
eg. VACTERL defects
What tissue type is affected in VACTERL defects?
What are the different defects?
VACTERL = mesoderm defect
- Vertebral defects
- Anal atresia
- Cardiac defects
- Tracheo-esophageal fistula
- Renal defects
- Limb defects
A newborn presents with poor sucking reflexes, irritability, tremors, and high pitched crying.
What substance did mom likely use throughout pregnancy?
What is this syndrome called
Opioids
Neonatal abstinence syndrome
Supplementation with what substance can prevent neural tube defects?
Folic acid
A newborn presents with a smooth philtrium, thin upper lip, and microcephaly.
What is the most likely cause?
Name 3 additional complications
Fetal alcohol syndrome
- Intellectual disability & overall growth retardation
- Limb dislocation
- Heart defect
Pregnant women using cocaine and nicotine are at increased risk for what 4 problems?
Why do these occur?
- IUGR -> Low birth weight
- Placental problems -> Preterm labor
- These occur because cocaine and nicotine cause vasoconstriction
What birth defects are caused by thalidomide?
Limb defects (eg. flipper limbs)
*Call the Midwife children
What fetal organ is damaged by ACE-I’s?
Kidney
