Gabbe Chapter 9

Question 1

The term for the lightness or darkness of ultrasound images

Answer 1

Gain

Question 2

Setting that shows changes along a single ultrasound beam over time (used to document fetal heart rate)

Answer 2

M-mode (motion mode)

Question 3

At ___ weeks gestation, the uterus has grown enough that advantages of transvaginal US are lost

Answer 3

10-12 weeks

Question 4

Gestational sac can be seen around __ weeks gestation

Answer 4

4-5 weeks gestation

Question 5

Until ___ weeks gestation the CRL should be measured for gestational age determination

Answer 5

12 weeks gestation

Question 6

The stomach can be consistently seen by __ weeks gestation

Answer 6

11 weeks gestation

Question 7

When cardiac activity has been demonstrated, the miscarriage rate is __ (A. 0-1%; B. 2-4%; C. 8-10%; D. 12-15%)

Answer 7

2-4% (although higher in high risk populations such as women >35 years undergoing infertility treatments)

The rate of spontaneous abortion in all clinically established pregnancies is 15% (reduced after cardiac activity is demonstrated)

Question 8

First trimester ultrasound findings predictive of a chromosome abnormality:

Answer 8

thick nuchal translucency, absent nasal bone, abnormally fast or slow heart rate

Question 9

In a twin gestation, an early pregnancy ultrasound showing a “lambda sign” indicates…?

Answer 9

the presence of two chorions

Question 10

What is the definition of polyhydramnios (AFI)?

Answer 10

greater than 24cm

Question 11

What is the definition of polyhydramnios (MVP)?

Answer 11

Greater than 8 cm

Question 12

What is the definition of oligohydramnios (AFI)?

Answer 12

Less than 5 cm

Question 13

What is the definition of oligohydramnios (MVP)?

Answer 13

Less than 2 cm. ACOG recommends using MVP as the definition of oligohydramnios to use to make clinical decisions as AFI is less reliable in predicting perinatal outcomes

Question 14

Placental edge that ends ___ cm or more from the cervix is considered normal (at 16 weeks or greater gestation)

Answer 14

2 cm

Question 15

How do you manage a patient with a placental edge less than 2cm from the internal os but not covering it?

Answer 15

low-lying placenta –> follow up US at 32 weeks gestation

Question 16

Condition where fetal vessel runs through the membranes over or close to the cervix

Answer 16

vasa previa (can occur with velamentous cord insertion, when there is a succenturiate lobe, or when a previa resolves)

Question 17

A “globular’ placenta with a narrow base compared to height is associated with what?

Answer 17

increased rate of IUGR and fetal death

Question 18

What is the lower limit of normal for a cervical length in the mid-second trimester?

Answer 18

25mm

Question 19

What method of measuring (BPD, CRL, AC, HC, FL) is most susceptible to variations in fetal soft tissue mass?

Answer 19

AC (abdominal circumference) - fairly good marker of fetal growth

Question 20

Is FGR caused by nutritional deprivation symmetric or asymmetric?

Answer 20

Asymmetric (AC is less than HC)