Fetal Assessment Flashcards
(40 cards)
US purpose in first trimester?
-estimate gestation age (+5-7 days)
-assess vaginal bleeding source
-determine if multiple fetuses are present
-examine for indications of birth defects of the brain/spine
US purpose in 2nd trimester?
-estimate gestational age (accuracy +7-10 days)
-determine size, position of placenta, fetus and umbilical cords
-examine for indications of major birth defects (cardiovascular/neural tube)
US purpose in 3rd trimester?
-estimate gestational age (accuracy +21-30 days)
-assess fetal viability
-determine size and position of placenta, fetus, and umbilical cord
-estimate volume of amniotic fluid
what is CVS, why and how is it preformed?
-chorionic villus sampling - chromosomal, DNA and enzymatic analysis is done on the tissue
-preformed by inserting a catheter into the uterus to obtain placenta villi for testing
how is a preformed amniocentesis?
US guided 22 gauge spinal needle in the uterine cavity, first few drops of fluid are discarded, 15-20ml of amniotic fluid is withdrawn and placed in tube. US monitored the removal and then for any leakage. FHT are monitored.
When are amniocentesis preformed and why?
-15-20 weeks to evaluate for genetic disease
-30-35 weeks to determine fetal lung maturity
Risk for amniocentesis?
-streaming (leakage of fluid)
-if the mother is Rh-negative, she is given Rh immune globulin immediately
-miscarriage risk is 1 in 1600
-infection of the placenta (chorioamnionitis) is rare
what is chorioamnionitis?
infection of the placenta
List the 5 part of the BPP
Fetal Heart Rate, Fetal Respirations, Fetal Movement, Fetal Tone and Amniotic
BPP: explain how Fetal Heart Rate is measured
- measures FHR and accelerations (NST)
- REACTIVE: 2+ FHR accelerations of 15 BMP above baseline for 15+ secs in a 20-40 min period
- NONREACTIVE: 0-1 FHR accelerations in 40 mins
BPP: Explain how Fetal Respirations are measured including what is normal and abnormal
- assessed by US
- one or more episode of rhythmic breathing for 30 seconds or more in 30 min period
- less then 30 seconds of rhythmic breathing in 30 seconds
BPP: explain Fetal Movement, the normal and abnormal
-Assessed by US and toco
- normal: 3 or more separate movements in 30 mins
- abnormal: less then 2 movements in 30 mins
BPP: Explain Fetal Tone, normal and abnormal
-assessed via US
- 2 or more episodes of extensions and flexion of arm/leg (or opening/closing of a hand)
- no extension/flexion
BPP: explain Amniotic Fluid Volume, normal and abnormal
- assessed by US and amniotic fluid index
- normal: at least one single vertical pocket greater then 2 cm
- abnormal: largest single vertical pocket is less then 2 cm
How is a normal BPP scored?
10/10, 8/10 (no NST), or 8/10 (-2 points for movement, tone, or breathing but not amniotic fluid) = normal test result
Equivacal Result of BPP score explained
- ## 6/10 (-4 points for two of movement, tone or breathing, but +2 for amniotic fluid) = equivocal result = a significant possibility of developing fetal asphyxia cannot be excluded, test needs to be repeated or fetus needs to be delivered
Explain abnormal BPP result (2)
-6/10 or 8/10 with 0 points for amniotic fluid = abnormal result risk of fetal asphyxia within 1 week is high
-4-0/10 = abnormal result; risk of fetal asphyxia within one week is high, delivery is usually indicated
What is alpha-fetoprotein (AFT) and how is it measured?
When is this test most accurate?
-AFT is protein produced by the yolk sac for the 6 weeks of gestation and then by the fetal liver. Levels peak about 15 weeks. This test is primarily used to detect neural tube defects. This is done with an amniocentesis. This test is most accurate at weeks 15-16 weeks.
What is included in the triple screening?
-serum AFT level, serum HCG, and estriol
What is test are in a quad screening?
AFP, HCG, Estriol, and Inhibin A
Who should get the Quad Screening done?
It is offered to everyone but is especially to those with history of brith defects in family, over the age or 35 and use of teratogenic medications during pregnancy, DM with insulin use, exposure to high dose radiation, and hx of viral infection during pregnancy
Positive Neural Tube Defects results in Quad Screening?
AFP - HIGH
HCG - Normal
Estriol - Normal
Inhibin A - Normal
Positive Quad Screen for Trisomy 21 results?
AFP - Low
HCG - HIGH
Estriol - Low
Inhibin A - High
Positive Quad Screening for Trisomy 18?
AFP - Low
HCG - Low
Estriol - Low
Inhibin A - Low
