Prenatal Assessment of Fetus Flashcards
When is a routine US screening performed to detect fetal malformations?
18-20 wks
Is US used to determine fetal sex?
Not necessarily a part of the routine level I obstetric US
Biophysical Profile components
(2 points apiece [8-10 reassuring of fetal well-being]
Amniotic Fluid volume Fetal Tone Fetal Activity Fetal Breathing Non-stress Test
When is NST performed? Non-stress Test is reactive/reassuring if? If non-reactive then what?
32-24 wks if High-risk. 40-41 wks for undelivered pts.
Reactive if there are 2 accelerations of the FHR in 20 minutes that are at least 15 beats above baseline that last 15 seconds.
If non-reactive, assess fetus via US.
Contraction Stress test is obtained by?
When is a CST considered positive?
Getting 3 contractions in 10 minutes and analyzing FHR tracing during this period, using reactivity criteria same as NST.
Positive if there are Late Decelerations with at least half of the contractions
How is Percutaneous Blood Sampling performed? When is it performed?
transabdominal needle into uterus to obtain blood from umbilical cord in settings of Rh isoimmunization, Fetal anemia, Hydrops, Fetal Transfusion, Karyotype analysis
How is Fetal Lung maturity tested? Significance of L/S ratio?
Amniocentesis to obtain amniotic fluid sample.
L/S >2 is associated with fetal lung maturity and decreased incidence of RDS. Lecithin increases as lungs mature (Sphingomyelin decreases)
What test is often done in conjunction with BPP?
Fetal Doppler study which assesses for flow in the umbilical artery
Decreased diastolic flow in the umbilical artery is concerning for?
Increased placental resistance
