EXAM 2025 QUESTIONS AND ANSWERS
What category rules out fetal acidemia? - ANS Cat 1
What maternal conditions greatly impact fetal oxygenation? - ANS Severe astha, cardiac
issues, and ecclampic seizures
Where does the exchange of O2 and nutrients take place? - ANS intervillous space
How is o2 blood transferred to the fetus? - ANS O2 enters the intervillous space via the
maternal arteries, to the villi then the umbilical vein take the o2 blood to the fetus. The
umbilical arteries take the deO2 blood from the baby through the villi and back to the mother
Diffusion - ANS High to low concentration
Mom to fetus for O2
Low to high concentration for CO2 so baby to mom
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,How is O2 transferred from mom to baby - ANS Diffusion
Explain spiral arteries in placenta - ANS Carry O2 into intervillous space
Are maximally dilated so they can not be increased
What are factors that can decrease uteroplacental blood flow? - ANS Maternal conditions
like pre-e and cardiac disease
Maternal hypotension
Placental changes- abruptions, infections, edema, or smaller size
Excessive uterine activity
Vasoconstriction
What happens to the spiral arteries during pre-e? - ANS They are constricted which
decreases blood flow
Why does the supine position cause decreased uteroplactenal blood flow? - ANS The aorta
and vena cava get compressed (20 weeks)
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, Why does maternal hypotension happen after regional analgesia? - ANS Blocks the
sympathetic pathway
Pooling of blood in the lower extremities decreases blood flow back to moms heart which
decreases blood flow to the fetus
What percentage is uteroplacental blood flow decreased by during cxts? - ANS 60%
Explain the pathway for maternal- fetal exchange for fetal oxygenation (basic) -
ANS Environment to lungs to heart to vasculature to uterus to placenta to umbilical cord
Where is the least O2 blood in the fetus? - ANS Limbs, kidneys, and descending aorta
Where is the most O2 blood in the fetus? - ANS Umbilical vein and ductous venous
Connects the umbilical vein to the inferior vena cava, bypassing the liver
Shunt that allows most O2 blood to fetal heart - ANS Ductus venosus
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