Structural Defects Flashcards
Congential means
born with
What is the rate of congenital defects
1 in 33
What is the most common cause of death in the first year
death from complications related to congenital defects
Anomoly
Deviation from normal - general term
Defect
Imperfection, lacking, deficient - general term
Morpogenesis
The development of a specific organ or tissue
Malformation
primary morphogenesis error, intinsic abrnormal development
anencephaly
born missing parts of the brain and skull - typically missing frontal and cerebral cortex, has neural tube defects - can be caused by lack of folate
Disruptions
secondary destruction of a previously normal organ system by a internal biologic factor i.e. amniotic band
Deformation
abrnomality caused by applied abnormal force to the fetus
What are the results of amniotic bands
caused by rupture of amniotic sac that causes fibrous bands that constricts limbs and blood flow, resulting in distal hypoplasia or amputation
Club feet: disruption or deformation?
Deformation - caused by in utero compression
Maternal causes of deformations
- First pregnancy
- small uterus
- malformed uterus
- leiomyomas
Fetal/placental causes of defomrations
oligohydramnios
multiple gestations
abnormal fetal presentation during deliveruy
Isolated defects
Single defect that accounts for 50-60% of al defects, usually only one organ system affected
Grouping defects - what are the three types
Sequence
Syndrome
Association
Association
Group of anomalies found together more often than statistical chance implies should happen - no idea why
VACTERL
Sequence
defects caused by a single original abnormality (dominoes falling from a single point)
Syndrome
group of anomalies that are related in cause but have their origins in different areas (dominoes knocked over from different points)
VACTERL (Association)
Veterbral Anal atresia Cardiac TE Fistula Renal and radial Limb
Potter sequence (Sequence)
Oligohydrmnios - decreased amniotic fluid Flat face atypical hands and feet hypoplastic lungs breech delivery
Agenesis
abscence of organ AND premordial cells
Aplasia
Absence of organ due to lack of premodial development
Atresia
Absence of opening to hollow organ
Dysplasia
Abnormal organization of cells
What is the break down of known and unknown genetic anomalies
Unknown 50-75%
Chromosomal - 10-15%
Single gene - 2-10%
Multifactorial (genes and environement) - unsure
What percent of aneuploid fetuses die in utero
80%
What chromosome is involved in Down, Patau and Edwards syndromes
21, 13, and 18 respectivley
What infections can cause genetic anomalies in fetuses
CHEAP TORCHES Chicken Pox Heapatitis Enterovirus Aids/HIV Parvo B19
Toxoplasmosis Other: GBS, Listeria, Candidia Rubella CMV HSV Every STD - gonorrhea, chlamydia, ureaplasma, HOV Syphyllis
Infant symptoms from CHEAP TORCHES infections
fever, poor feeding, peticiae, jaundice, blindness, hearing loss, hepatosplenomegaly, blueberry muffin babies
Two examples of multifactorial anomalies
Hip Dysplasia, Cleft Palate
how long is the embryo mostly unaffected by toxins
2 weeks
What period of time is the CNS susceptible to exposure
3 weeks to full term
What period of time is the heart susceptible to exposure
3 weeks to 8 weeks
What period of time are the arms and legs susceptible to exposure
4 weeks to 8 weeks
What period of time are the eyes susceptible to exposure
4 weeks to full term
What period of time are the teeth susceptible to exposure
6 weeks to 16 weeks
What period of time is the palate susceptible to exposure
6 weeks to 9 weeks
What period of time are the external genitalia susceptible to exposure
7 weeks to full term
cleft palate is thought to be related to what pathway
TGF Beta
