All of the following can be used to determine a chromosome analysis of the fetus except
A. AmniocentesisB. Chorionic villus sampling
C. Percutaneous umbilical blood sampling (PUBS)
D. Fetal umbilical Doppler velocimetry
The answer is D
Fetal tissue for
chromosome analysis can be obtained via amniocentesis, chorionic villus
sampling (CVS), percutaneousumbilical blood sampling, or direct biopsy of fetal
muscle or skin. Amnio- centesis involves obtaining a sample of amniotic fluid,
which contains fetal fibroblasts. Chorionic villus sampling involves taking a
biopsy of the placenta. In the case of PUBS, the umbilical vein is punctured
under direct ultrasound guidance near the placental origin and blood is
obtained for genetic analysis. Doppler velocimetry is an ultrasound technique
used to examine blood flow through the umbilical artery. IUGR has been
associated with abnormal umbilical artery Doppler velocimetry. Therefore, this
technique is used with other modalities such as BPP and NSTS to monitor fetal
wellbeing.
