PU Multiple Gestation Ultrasound 2

Question 1

What defines Quintero Stage II in twin-to-twin transfusion syndrome (TTTS)?

Accepted Answer

Oligohydramnios-polyhydramnios sequence with an absent donor bladder

Answer

Stage II is characterized by the TOPS sequence progressing to the point where the donor's bladder is no longer visible due to oliguria from severe volume depletion.

Question 2

Selective intrauterine growth restriction (sIUGR) in monochorionic twins is primarily defined by which finding?

Accepted Answer

EFW of one twin below the 10th percentile for gestational age

Answer

sIUGR is defined as EFW below the 10th percentile in one monochorionic twin, distinguishing it from TTTS which requires the oligohydramnios-polyhydramnios sequence.

Question 3

Twin anemia-polycythemia sequence (TAPS) is best identified on ultrasound by which Doppler finding?

Accepted Answer

Middle cerebral artery peak systolic velocity (MCA-PSV) >1.5 MoM in the anemic twin

Answer

MCA-PSV >1.5 MoM is the standard Doppler marker for fetal anemia; in TAPS the donor becomes anemic, and this finding distinguishes TAPS from TTTS.

Question 4

In a naturally conceived triplet pregnancy, what is the most common chorionicity-amnionicity configuration?

Accepted Answer

Trichorionic-triamniotic

Answer

Spontaneous triplets arise from three separately ovulated and fertilized eggs in the vast majority of cases, resulting in trichorionic-triamniotic placentation.

Question 5

What is the standard recommended ultrasound surveillance interval for uncomplicated monochorionic-diamniotic (MCDA) twin pregnancies to screen for TTTS?

Accepted Answer

Every 2 weeks starting from 16 weeks of gestation

Answer

MCDA twins require every-2-week ultrasound surveillance beginning at 16 weeks to detect TTTS early, as it most commonly develops between 16 and 26 weeks.

PU - Pregnancy Ultrasound Certification Practice Test

PU - Pregnancy Ultrasound Certification Practice Test

PU Multiple Gestation Ultrasound 2