Fetus Flashcards
What vessel delivers oxygen and nutrients to fetus?
Umbilical vein
What can be associated with a single umbilical artery?
Anomalies of the urogenital tract, gastrointestinal tract or cardiac system
Consider chromosomal anomalies
What is associated with velamentous insertion of the umbilical cord?
Occurs when the umbilical cord inserts outside of the placenta
Increase risk of intolerance of labor.
Increased risk, a prematurity and low birth weight
Occurs in almost all triplet gestations
What is associated with vasa previa?
Fetal blood loss due to rupture of the umbilical vessels.
Prenatal diagnosis should lead to planned cesarean section
What creates Alpha-Fetoprotein (AFP)?
Early — fetal yolk sac
Late — fetal liver and GI tract
What is associated with elevated AFP (>2-2.5)?
Open neural tube defects
Omphalocele/gastroschisis
GI obstruction
Polycystic kidneys
Multiple gestation
Low birth weight
What is associated with low AFP (<0.6)?
Trisomies
Fetal death
When do you measure nuchal translucency? What is abnormal and what can it signify?
Measured between 10-14 weeks
>3mm is abnormal
Increase risk of aneuploidy (1 out of 6) or cardiac anomaly
When combined with maternal age risk, how is nuchal translucency detection of trisomy 21? Trisomy 18?
21: 78-89%
18: 91%
What is absent nasal bone associated with?
T21
What are the components of the quad screen?
Maternal AFP, Maternal estriol, Maternal B-hCG, and inhibin A
Low AFP, high B-hCG, low estriol, and high inhibin A
Trisomy 21
75-81% detection
Low AFP, low B-hCG, low estriol, normal inhibin A
T18
What trisomy can quad screen not detect?
T13
When do you collect fetal cell-free DNA? Where does it come from?
Any time after 9 weeks gestation
Fetal erythroblasts apoptosis and the products cross placenta into maternal circulation
