WorksheetsReview Chapter 17 first trimester ultrasound
Total questions: 49
Worksheet time: 25mins
What is the most accurate method for determining gestational age in the first trimester?
Biparietal diameter
Crown–rump length
Femur length
Head circumference
A normal gestational sac should be visualized by transvaginal ultrasound when β-hCG levels reach approximately:
100–300 mIU/mL
500–800 mIU/mL
1,000–2,000 mIU/mL
5,000–7,000 mIU/mL
Which structure is the first definitive sonographic sign of an intrauterine pregnancy?
Yolk sac
Amniotic membrane
Double decidual sac sign
Embryo with cardiac activity
The yolk sac should always be visualized once the gestational sac reaches:
5 mm
8 mm
10 mm
12 mm
Cardiac activity should be detected when the embryo measures at least:
1 mm
2 mm
5 mm
7 mm
Which of the following best describes the normal growth rate of the gestational sac?
0.5 mm per day
1 mm per day
1.5 mm per day
2 mm per day
The normal location for the gestational sac is:
Fundal region near the cornua
Anterior lower uterine segment
Central endometrial cavity
Within the myometrium
The presence of a gestational sac without a yolk sac or embryo after the sac reaches 25 mm suggests:
Normal early pregnancy
Ectopic pregnancy
Anembryonic pregnancy
Heterotopic pregnancy
The nuchal translucency exam is performed between:
6–8 weeks
8–10 weeks
11–14 weeks
15–20 weeks
The double bleb sign consists of the yolk sac and which other structure?
Chorionic cavity
Amniotic cavity
Embryonic pole
Decidualized endometrium
Which of the following is NOT a typical indication for first-trimester ultrasound?
Evaluate viability
Screen for chromosomal abnormalities
Measure AFI
Confirm gestational age
A subchorionic hemorrhage typically appears as:
Highly echogenic mass
Cystic region within the placenta
Hypoechoic collection between chorion and uterine wall
Anechoic mass within the ovary
Which finding is most concerning for pregnancy failure?
Yolk sac measuring 4 mm
Fetal heart rate of 170 bpm
Embryo measuring 8 mm with no cardiac activity
Gestational sac measuring 10 mm with no embryo
Which structure normally forms first in embryologic development?
Yolk sac
Amnion
Chorionic villi
Embryonic pole
A pseudogestational sac is commonly associated with:
Molar pregnancy
Ectopic pregnancy
Multiple gestation
Blighted ovum
A positive “ring of fire” sign on Doppler most commonly suggests:
Corpus luteum
Molar pregnancy
Early IUP
Nabothian cyst
The best transducer for early first-trimester imaging is:
2 MHz curved array
3.5 MHz phased array
5–7.5 MHz transvaginal probe
12 MHz linear array
The amniotic membrane normally fuses with the chorion around:
6–7 weeks
8–9 weeks
10–14 weeks
15–20 weeks
Which sonographic finding is most suspicious for ectopic pregnancy?
Thickened endometrium
Free fluid in the cul-de-sac
Adnexal ring sign
Retroverted uterus
Early gestational cardiac activity typically begins at approximately:
4–5 weeks
5.5–6 weeks
7–8 weeks
9–10 weeks
The normal appearance of the yolk sac is:
Echogenic without borders
Anechoic center with echogenic rim
Two echogenic layers separated by fluid
Isoechoic to the embryo
Which finding supports a diagnosis of complete miscarriage?
Open cervix with retained products
Closed cervix with present gestational sac
Empty uterus following prior confirmed IUP
Slow fetal heart rate
A thick, echogenic ring surrounding the gestational sac is known as the:
Decidua capsularis
Chorionic bump
Double decidual sac sign
Amniotic membrane
The most reliable sign of pregnancy viability is:
Presence of yolk sac
Cardiac activity
Gestational sac in the uterus
Normal hCG levels
Which biometric parameter is the most accurate for estimating gestational age in the second trimester?
Abdominal circumference
Femur length
Biparietal diameter
Head circumference
The biparietal diameter (BPD) should be measured at the level of the:
Choroid plexus and lateral ventricles
Falx, thalami, and cavum septi pellucidi
Cerebellum and cisterna magna
Orbits and nasal bone
The head circumference (HC) measurement is preferred over BPD when:
The fetus has a breech presentation
The head is elongated (dolichocephaly)
The head is round (brachycephaly)
The placenta is posterior
Which measurement is most useful for assessing fetal weight late in pregnancy?
HC
BPD
AC
Cerebellar diameter
Femur length (FL) is measured:
Including distal epiphyseal cartilage
Between the outer borders of both femoral heads
Excluding the femoral head and distal epiphysis
From the trochanter to the patella
A normal cerebellar diameter in millimeters should approximately equal the gestational age in weeks between:
12–20 weeks
14–22 weeks
15–25 weeks
18–30 weeks
Abdominal circumference (AC) is measured at the level of the:
Fetal kidneys
Liver and stomach with the spine visible
Heart and diaphragm
Umbilical cord insertion
The best parameter to assess fetal growth disturbances such as IUGR is:
BPD
HC
AC
FL
The FL/AC ratio is most useful for identifying:
Growth-restricted fetuses
Macrosomic fetuses
Skeletal dysplasias
Neural tube defects
A fetus with a BPD below the 5th percentile but normal HC may have:
Microcephaly
Dolichocephaly
Macrosomia
Hydrocephalus
Which biometric measurement increases the most variability in late gestation?
HC
BPD
FL
AC
Which method is used to calculate estimated fetal weight (EFW)?
BPD and AC
Head measurements only
Multiple biometric parameters in standardized formulas
Doppler peak systolic velocity of the umbilical artery
The normal ratio of HC/AC gradually:
Increases throughout pregnancy
Decreases throughout pregnancy
Remains stable after 20 weeks
Increases only after 35 weeks
A femur that measures more than 2 weeks behind expected size may indicate:
Macrosomia
Skeletal dysplasia
Wrong fetal position
Incorrect AC measurement
The presence of limb bowing or fractures with shortened measurements suggests:
Constitutionally short fetus
Growth restriction
Lethal skeletal dysplasia
Oligohydramnios
The most reliable method for determining gestational age in the third trimester is:
BPD
HC
AC
No measurement is highly accurate
Which of the following is NOT typically used for biometric dating after 30 weeks?
BPD
HC
AC
Femur epiphyseal ossification centers
Which Doppler index is most useful in evaluating fetal growth restriction?
Middle cerebral artery S/D ratio
Umbilical artery S/D ratio
Uterine artery PI
Ductus venosus waveform
A fetus with symmetric IUGR typically has:
Decreased AC only
Head measurements preserved
Proportionately small HC, AC, and FL
Femur length disproportionately short
Asymmetric IUGR is most commonly associated with:
Chromosomal abnormalities
First-trimester infections
Placental insufficiency
Triploidy
Macrosomia is most strongly predicted by which measurement?
HC
BPD
AC
FL
If the cerebellar diameter is 24 mm, the estimated gestational age is approximately:
18 weeks
20 weeks
24 weeks
30 weeks
The term “cephalic index” refers to the ratio of:
BPD to OFD
HC to AC
AC to FL
HC to FL
The most concerning finding for hydrocephalus is:
Increased AC
Large cisterna magna
Increased BPD with increased HC
Small cerebellar diameter
Which biometric parameter is LEAST affected by fetal growth abnormalities?
AC
FL
BPD
HC
