Prenatal Flashcards
1
Q
Diagnostic techniques (3)
A
Chorionic villus sampling Amniocentesis Cordocentesis (PUBS)
2
Q
Chorionic villus sampling
A
- can be performed transcervical or transabdominal
- performed 11-13 weeks
- problems: placental mosaicism (1-2%)
3
Q
Amniocentesis
A
- performed >15 weeks
- can directly measure AFP and acetyl cholinesterase
- Risk of miscarriage = 1/1000
- Takes amniotic fluid; FISH results in 48 hours, Karyotype in ~2 weeks
4
Q
Cordocentesis (percutaneous umbilical blood sampling - PUBS)
A
- needle inserted into fetal umbilical cord
- performed >18-20 weeks
- diagnoses fetal blood: hematocrit, platelets, infection
- therapeutic: transfusion, drugs
5
Q
Screening techniques (5)
A
- First Trimester Screening
- Integrated/Sequential Screening
- Second trimester multiple marker screening
- Ultrasound
- NIPT
6
Q
First Trimester Screening
A
- tests for Tri 18 and Tri 21
- performed 11-14 weeks
- NT measurement via u/s
- hCG and PAPP-A measurement
- risk adjustment
- Tri 18; Tri 21 risk flagged if greater than 1/270
7
Q
Quad Screening
A
- Performed 16-22 weeks
- blood test measuring hCG, AFP, eU3 and inhibin A
- risk adjustment
- Tri 18, Tri 21 and open NTD
- Tri 21 risk flagged if greater than 1/270
8
Q
NIPT
A
- performed anytime after 10 weeks
- blood test
- detects Tri 13, Tri 18, Tri 21 and XY
- can also detect Tri 16, Tri 22 and 7 microdeletions
- can pick up placental mosaicism
9
Q
Ultrasound
A
- level 2 anatomy scan performed at 18-20 weeks
- can detect open NTD, Tri 21, Tri 13 and Tri 18
10
Q
Integrated/Sequential/Combined Screening
A
-combines first trimester screening and quad screening for more accurate results
11
Q
High risk pregnancy (features/qualifications)
A
- over 35 at delivery
- abnormal FTS/maternal serum screen
- abnormal ultrasound finding
- personal/family history of aneuploidy
12
Q
IDDM (Insulin-Dependent Diabetes Mellitus) marker levels
A
- have lower MSAFP values than non-IDDM
- higher incidence of open NTDs
13
Q
African American marker levels
A
- have a higher MSAFP concentration
- lower incidence of open NTDs
14
Q
Reasons for elevated MSAFP
A
- underestimate gestational age
- multiple pregnancy
- open NTDs
- abdominal wall defect
- fetal and maternal blood mixed
- unexplained
15
Q
Indications to test Amniotic fluid AFP and Acetylcholinesterase
A
- AFAFP >2.00 MoM
- patient at increased risk for an open NTD based on family history
- patient with IDDM
- patient with elevated MSAFP
- patient on valproic acid or tegretol