US in preg

Question 1

What is the earliest use of ultrasound in pregnancy?

Answer 1

Confirming an intrauterine pregnancy.

Question 2

What is the most accurate method for dating pregnancy in the first trimester?

Answer 2

Crown-rump length measurement.

Question 3

When can a gestational sac be seen on transvaginal ultrasound?

Answer 3

Around 4.5 to 5 weeks.

Question 4

When is the yolk sac usually visible?

Answer 4

Around 5.5 weeks.

Question 5

When can fetal cardiac activity be detected?

Answer 5

Around 6 weeks.

Question 6

What is the significance of detecting fetal cardiac activity by ultrasound?

Answer 6

Confirms a viable intrauterine pregnancy.

Question 7

What structure is used to confirm viability in early pregnancy?

Answer 7

Fetal cardiac motion.

Question 8

When is crown-rump length measurable?

Answer 8

By 7 weeks gestation.

Question 9

What are indications for first-trimester ultrasound?

Answer 9

Dating, viability, ectopic pregnancy, multiple gestations, molar pregnancy.

Question 10

What is measured during first-trimester nuchal translucency screening?

Answer 10

Nuchal translucency thickness between 11–13.6 weeks.

Question 11

What is the most accurate way to date pregnancy if unsure of LMP?

Answer 11

First-trimester ultrasound using CRL.

Question 12

When is the anatomy scan typically performed?

Answer 12

Between 18 and 22 weeks.

Question 13

What is the main purpose of the anatomy scan?

Answer 13

To assess fetal structure and detect congenital anomalies.

Question 14

What ultrasound parameters are used to estimate fetal growth in the second and third trimesters?

Answer 14

Biparietal diameter, head circumference, abdominal circumference, femur length.

Question 15

How is fetal sex usually determined?

Answer 15

During the second-trimester anatomy scan.

Question 16

What imaging modality is used to evaluate placenta previa?

Answer 16

Transvaginal ultrasound.

Question 17

What is the best tool to assess cervical length for preterm labor risk?

Answer 17

Transvaginal ultrasound.

Question 18

What is the definition of a short cervix in pregnancy?

Answer 18

Cervical length <25 mm before 24 weeks.

Question 19

What is assessed in a biophysical profile (BPP)?

Answer 19

Fetal tone, movement, breathing, amniotic fluid, and non-stress test.

Question 20

When is a biophysical profile indicated?

Answer 20

In high-risk pregnancies or suspected fetal compromise.

Question 21

What measurement is used to assess amniotic fluid volume?

Answer 21

Amniotic Fluid Index (AFI) or single deepest pocket.

Question 22

What condition is suggested by an AFI <5 cm?

Answer 22

Oligohydramnios.

Question 23

What condition is suggested by an AFI >24 cm?

Answer 23

Polyhydramnios.

Question 24

When is Doppler ultrasound of the umbilical artery indicated?

Answer 24

When intrauterine growth restriction (IUGR) is suspected.

Question 25

What finding on Doppler suggests severe IUGR?

Answer 25

Absent or reversed end-diastolic flow.

Question 26

What is the best imaging modality to assess for ectopic pregnancy?

Answer 26

Transvaginal ultrasound.

Question 27

What is the next step if β-hCG is above the discriminatory zone and no intrauterine pregnancy is seen?

Answer 27

Suspect ectopic pregnancy.

Question 28

What is the use of ultrasound in multiple gestations?

Answer 28

Determine chorionicity and amnionicity.

Question 29

What is the earliest gestational age at which chorionicity can be determined accurately?

Answer 29

Before 14 weeks.

Question 30

What is the twin-peak (lambda) sign suggestive of?

Answer 30

Dichorionic diamniotic twins.

Question 31

What is the best time for detailed anatomic survey in twins?

Answer 31

18–22 weeks (same as singletons).

Question 32

What is used to monitor fetal anemia in Rh sensitization?

Answer 32

Doppler assessment of the middle cerebral artery (MCA peak systolic velocity).

Question 33

What is the earliest gestational week when fetal cardiac activity must be seen if the embryo measures ≥7 mm?

Answer 33

6.5–7 weeks.

Question 34

What condition is evaluated using serial ultrasounds for fetal growth and wellbeing?

Answer 34

Suspected IUGR or macrosomia.

Question 35

What ultrasound sign is characteristic of complete placenta previa?

Answer 35

Placenta covers the internal cervical os.

Question 36

What trimester is most appropriate for dating if LMP is uncertain?

Answer 36

First trimester (most accurate).

Question 37

What is a common use of ultrasound in the third trimester?

Answer 37

Assess fetal growth, amniotic fluid, presentation, and placental location.

Question 38

What is the ultrasound modality of choice to assess early pregnancy complications?

Answer 38

Transvaginal ultrasound.

Question 39

What is the most reliable way to confirm fetal presentation near term?

Answer 39

Ultrasound at or after 36 weeks.

Question 40

What imaging is used to guide obstetric procedures such as amniocentesis?

Answer 40

Real-time ultrasound.