Obstetric Procedures

Question 1

used in first trimester, producing high-resolution images

that are not influenced by maternal BMI

Answer 1

Transvaginal sonogram

Question 2

Dating accuracy of first trimester sonogram

is ________

Answer 2

+/- 5–7 days.

Question 3

used any time during the pregnancy, but image quality may be limited by maternal obesity

Answer 3

Transabdominal sonogram

Question 4

Dating accuracy of early second trimester sonogram is +/- _______

Answer 4

7-10 days.

Question 5

_____used to assess umbilical artery (UA) and middle cerebral artery (MCA) blood flow.

This modality assesses fetal well-being in IUGR pregnancies as well as fetal anemia in alloimmunized pregnancies.

Answer 5

Doppler ultrasound studies

Question 6

Indications for obstetrical ultrasound include:

Answer 6

• Pregnancy location & viability, gestational age dating
• Multiple gestation (zygosity, chorionicity, amnionicity)
• Amniotic fluid volume (oligohydramnios, polyhydramnios)
• Fetal growth (IUGR, macrosomia)
• Fetal anomalies, fetal well-being
• Pregnancy bleeding, fetal anemia

Question 7

ideally performed at 18-20 weeks, looks for anatomic markers of fetal aneuploidy

Answer 7

Genetic sonogram

Question 8

Specific markers for aneuploidy

Answer 8

nuchal skin fold thickness (strongest predictor), short long bones, pyelectasis, echogenic intracardiac focus, hyperechoic bowel

Question 9

________ measurement is a screening test, performed between 10-14 weeks, measuring the fetal fluid collection behind the neck.

Answer 9

Nuchal translucency (NT)

Question 10

A thickened NT increases the likelihood of_____ and ______

Answer 10

aneuploidy and cardiac disease

Question 11

It is combined with two maternal blood tests _______ and _______) in first-trimester screening to increase the sensitivity and specificity for aneuploidy screening.

Answer 11

(free b-hCG & PAPP-A

Question 12

_______ is a diagnostic outpatient office procedure performed under ultrasound guidance without
anesthesia. Procedure-related pregnancy loss rate is 0.7%

Answer 12

CVS

Question 13

In CVS,

Chorionic villi, which are placental precursors, are aspirated from a pregnant uterus between ______ and _____

Answer 13

10 and 12 weeks’ gestation

Question 14

_______is a diagnostic, outpatient office procedure performed after 15 weeks under
ultrasound guidance without anesthesia. Pregnancy loss rate is 0.5%

Answer 14

Amniocentesis

Question 15

Fetal karyotyping is performed on _______

Answer 15

amniocytes.

Question 16

NTD (neural tube defect) screening is performed on amniotic fluid with biochemical analysis ______ and ______

Answer 16

(AFP and acetylcholinesterase).

Question 17

This transabdominal procedure, performed under ultrasound guidance, aspirates fetal blood
from the umbilical vein after 20 weeks’ gestation

Answer 17

PERCUTANEOUS UMBILICAL BLOOD SAMPLE (PUBS)

Question 18

Purpose of PERCUTANEOUS UMBILICAL BLOOD SAMPLE (PUBS)

Answer 18

The procedure can be diagnostic (e.g., blood gases, karyotype, IgG and IgM antibodies)
as well as therapeutic (e.g., intrauterine transfusion with fetal anemia).

Question 19

Procedure-related pregnancy loss rate of PUBS is ________

Answer 19

1–2%.

Question 20

A _______ is a transabdominal procedure performed with a fiberoptic scope in the operating
room after 20 weeks under regional or general anesthesia

Answer 20

fetoscopy

Question 21

Indications for fetoscopy include _____ and ____

Answer 21

intrauterine surgery or fetal skin biopsy

Question 22

Laser is used for coagulating placental vessels in__________.

Skin biopsy may be performed for suspected ______

Answer 22

twin−twin transfusion syndrome (TTTS)

fetal ichthyosis

Question 23

The pregnancy loss rate of fetoscopy is _______

Answer 23

2−5%.