Prenatal Diagnostic Testing

Question 1

What are ultrasounds used for?

Answer 1

Presence of pregnancy and location, multifetal gestation, gestational age, viability, abnormalities

Question 2

What gestational age can gender be determined?

Answer 2

Around 12 weeks but isn’t always clear

Question 3

What is a color doppler used for?

Answer 3

To sight the umbilical vein and two arteries

Question 4

What pregnancy complications would a doppler ultrasound be used for?

Answer 4

Hypertension, fetal growth restriction, placental insufficiency

Question 5

When is a fetal anatomy scan done?

Answer 5

20 weeks

Question 6

What is an alpha-fetoprotein screening used for?

Answer 6

To sight open body wall defects/neural tube defects & chromosomal anomalies

Question 7

When is an AFP screening done?

Answer 7

16-18 weeks

Question 8

Where is alpha-fetoprotein found?

Answer 8

Maternal serum or amniotic fluid - blood is taken

Question 9

What is multiple marker screening?

Answer 9

Markers that are added to AFP testing - hCG and unconjugated estriol

Question 10

What does multiple marker screening increase the chance of finding?

Answer 10

Trisomy 18 or 21…. if positive amniocentesis is recommended

Question 11

What is chorionic villus sampling and when is it done?

Answer 11

Goes through cervix or abdomen to scrape a sample on villi in placenta. Done at 10-13 weeks

Question 12

What info does chorionic villus sampling bring us?

Answer 12

Chromosomal defects, metabolic/DNA abnormalities

Question 13

What is amniocentesis?

Answer 13

Aspirating amniotic fluid from sac

Question 14

When is the first time an amniocentesis would be done?

Answer 14

15-20 weeks (2nd trimester) to see chromosomal or biochemical abnormalities

Question 15

When is the second time an amniocentesis might be done?

Answer 15

3rd trimester…. to see fetal lung maturity if baby can survive on own and be delivered OR worried about ABO incompatibility

Question 16

What is percutaneous umbilical blood sampling used for?

Answer 16

Aspirates fetal blood in umbilical cord near placenta… detects blood disorders, acid-base imbalances, infection, genetic disease

Question 17

What does a non-stress test (NST) evaluate?

Answer 17

Fetal heart rate accelerations with or without movement. Variation is reassuring (fetus has O2 and neural pathways)

Question 18

When do we see reactivity in fetal heart rate? How can we stimulate it?

Answer 18

32 weeks - vibroacoustic stimulation

Question 19

What is a contraction stress test?

Answer 19

Oxytocin given or stimulated to make mom have contractions - sees how fetal heart responds

Question 20

What are the 5 parameters in a biophysical profile?

Answer 20

Non-stress test
Fetal breathing movements
Gross fetal movements
Fetal tone
Amniotic fluid volume (AFI)

Question 21

How can the mom assess fetal movement?

Answer 21

“Kick counts” - mother can count at least 10 fetal movements within 2 hours or 5-10 movements per hour

Question 22

When is genetic counseling offered?

Answer 22

Occurrence or risk of occurrence of genetic disease in the family

Question 23

Who should get genetic counseling? Examples.

Answer 23

Certain racial or ethnic groups, women >35, family history, previous child with disorder, women with past SABs, women with abnormal screenings, etc.