Free ARDMS OB/GYN Practice Test

Answer: B. That layered look is the trilaminar or "triple-line" endometrium. It builds through the proliferative phase and is clearest around ovulation, which is right where day 13 falls.

• A is wrong: during menses the endometrium is thin and irregular, sometimes with fluid or blood products.
• C is wrong: in the late luteal phase the layers fade and the endometrium becomes thicker and homogeneous.
• D is wrong: an atrophic endometrium is a thin single echogenic line, typical after menopause, not this trilaminar mid-cycle pattern.

Takeaway: Triple line points to proliferative or periovulatory; uniform and echogenic points to secretory.

Source: AIUM gynecologic ultrasound image companion, PDF pp. 29–34, menstrual-cycle and postmenopausal endometrial appearances.

Answer: A. In saline infusion sonohysterography (SIS), saline distends and outlines the cavity. That shows whether a fibroid is submucosal and how deeply it extends into the myometrium. The AIUM sonohysterography image companion shows how SIS reveals the submucosal location of a fibroid.

• B improves the acoustic window but doesn't outline the cavity.
• C measures uterine artery flow, which doesn't show the fibroid's relationship to the cavity.
• D doesn't distend and outline the uterine cavity.

Takeaway: For a question about the cavity, fill the cavity: SIS.

Source: AIUM sonohysterography image companion, PDF p. 8 (saline distension) and pp. 16–17 (submucosal fibroid).

Answer: C. The external fundus is the deciding feature. In the ASRM 2021 classification, a bicornuate uterus has an external fundal indentation greater than 1 cm.

• A is wrong: a septate uterus is defined by an internal septum more than 1 cm long with an acute leading-edge angle, while the external fundus is normal or only minimally indented.
• B is wrong: an arcuate uterus has a broad internal fundal indentation and no deep external cleft.
• D is wrong: a unicornuate uterus has a single, banana-shaped cavity.

Takeaway: Look outside first. A deep external cleft means bicornuate; a smooth fundus with an internal septum means septate.

Source: ASRM Müllerian Anomalies Classification 2021, diagnostic criteria for septate, arcuate and bicornuate uterus.

Answer: B. A reticular (lacy, fishnet) pattern of fibrin strands, sometimes with a retracting clot, and no internal vascularity is the typical hemorrhagic cyst in a premenopausal patient.

• A typically has uniform low-level ("ground-glass") echoes, not a lacy network.
• C has a bright component with shadowing, or echogenic lines and dots.
• D is less likely than the classic hemorrhagic-cyst pattern described here; absent Doppler flow alone does not exclude malignancy.

Takeaway: Lacy strands with no internal flow fit a typical hemorrhagic cyst.

Source: ACR O-RADS US v2022 assessment categories, PDF p. 2, “Classic Benign Lesions: Typical Hemorrhagic Cyst”; p. 1, risk categories and color score.

Answer: A. Uniform low-level "ground-glass" echoes, smooth walls and no internal flow make up the typical endometrioma pattern, and the history fits.

• B typically shows reticular strands or a retracting clot; those features aren't described here.
• C is anechoic.
• D shows echogenic fat, hair or calcification, often with shadowing.

Takeaway: Ground-glass echoes, smooth walls and no internal flow fit a typical endometrioma.

Source: ACR O-RADS US v2022 assessment categories, PDF p. 2, “Classic Benign Lesions: Typical Endometrioma.”

Answer: D. O-RADS describes the typical dermoid as a bright component with shadowing, or bright lines and dots, or floating echogenic spheres, with no internal flow. Classic teaching terms for the same features include the dermoid plug (Rokitansky nodule), "tip of the iceberg" shadowing and "dermoid mesh."

• A has uniform low-level echoes without shadowing.
• B is usually a solid myometrial mass connected to the uterus.
• C is typically a thick-walled complex mass with surrounding hyperemia in a patient with signs of infection.

Takeaway: A bright shadowing nodule or lines and dots with no internal flow fit a typical dermoid.

Source: ACR O-RADS US v2022 assessment categories, PDF p. 2, “Classic Benign Lesions: Typical Dermoid Cyst”; ISUOG, Ovarian mature cystic teratomas, “Ultrasound characteristics.” Sahin et al., Mature cystic teratoma of the ovary (2017), ultrasound signs; Velcani et al. (2010), PDF p. 3, tubo-ovarian abscess discussion.

Answer: C. An enlarged, edematous ovary with peripheral follicles plus acute pain is highly suspicious for torsion. Detectable flow does not exclude it, because twisting can be partial or intermittent and the ovary has a dual blood supply. The concern should be reported immediately for urgent clinical assessment.

• A is the classic trap: flow does not rule torsion out.
• B ignores the acute pain, the marked enlargement and the edema.
• D is wrong: a 7 cm edematous ovary is not normal.

Takeaway: Suspect torsion from the symptoms and grayscale findings. Flow doesn't clear it.

Source: Chang, Bhatt and Dogra, “Pearls and pitfalls in diagnosis of ovarian torsion,” RadioGraphics 2008, abstract and Figures 3–5.

Answer: A. The yolk sac is the first structure seen inside the gestational sac. In the 2024 SRU first-trimester lexicon, a normally located gestational sac containing a yolk sac is a definite intrauterine pregnancy.

• B comes later, typically around 6 weeks.
• C is a thin membrane usually seen after the embryo is visible.
• D describes the decidual layers around the sac, not a structure inside it. It raises confidence when the sac is still empty, which the lexicon calls a "probable" IUP, but it isn't required and isn't definitive.

Takeaway: A yolk sac inside a normally located intrauterine sac makes it a definite IUP. An empty sac in that location is only probable.

Source: SRU Lexicon for First-Trimester US (Rodgers et al., 2024), “Early Development” and “Pregnancy Location.”

Answer: C. Under the SRU consensus criteria, a mean sac diameter (MSD) of 25 mm or more with no embryo is diagnostic of early pregnancy loss. Another diagnostic criterion is a crown-rump length (CRL) of 7 mm or more with no cardiac activity.

• A is wrong: a correctly measured 26 mm sac with no embryo meets the SRU size-based criterion for early pregnancy loss.
• B is wrong: at 26 mm the finding has crossed from "concerning for" into "diagnostic of early pregnancy loss."
• D is wrong: the confirmed sac is normally implanted within the uterus; the finding describes an anembryonic intrauterine pregnancy. A coexisting ectopic (heterotopic pregnancy) is rare, and nothing here suggests one.

Takeaway: Two numbers to know cold: MSD of 25 mm or more with no embryo, or CRL of 7 mm or more with no cardiac activity.

Source: SRU Lexicon for First-Trimester US (2024), “Early Pregnancy Loss: Diagnostic of EPL” and anembryonic-pregnancy criteria.

Answer: B. With a positive hCG and no intrauterine pregnancy, an adnexal mass separate from the ovary is the most common finding in tubal ectopic pregnancy and strongly suggests a probable tubal ectopic pregnancy. Gentle probe pressure that separates the mass from the ovary is the key technique.

• A arises from the ovary and moves with it.
• C connects to the uterus by a stalk and looks like myometrium.
• D shows peristalsis and a layered bowel wall, and doesn't fit this clinical picture.

Takeaway: Positive hCG, empty uterus and a mass separate from the ovary: think ectopic.

Source: SRU Lexicon for First-Trimester US (2024), “Pregnancy Location: Tubal EP” and Figure 9 (exophytic corpus luteum).

Answer: D. An echogenic, multicystic intrauterine mass with no fetal parts and an hCG far above what the dates predict fits a complete mole. The high hCG over-stimulates the ovaries, producing theca-lutein cysts. Very early moles may not show the classic pattern yet. Histology confirms the diagnosis.

• A involves retained tissue after an early pregnancy loss and doesn't explain this characteristic cystic mass and marked hCG elevation as well.
• B is an empty gestational sac, not a mass full of cysts.
• C doesn't explain the hCG or the ovarian cysts.

Takeaway: Cyst-filled echogenic mass, no embryo and very high hCG: complete mole.

Source: Abdi et al., “Ultrasound Detection of a Molar Pregnancy in the Emergency Department,” West J Emerg Med 2013, Discussion and pathology confirmation; SRU first-trimester lexicon, “Incomplete EPL.” Fowler et al., Histomorphometric features of hydatidiform moles in early pregnancy (2007), abstract, Results and Conclusion.

Answer: B. This is the "T sign," which indicates a monochorionic diamniotic pregnancy. A triangular wedge of placenta running into the membrane, called the lambda or "twin peak" sign, would mean dichorionic. ISUOG recommends assigning chorionicity before 13+6 weeks; if transabdominal and transvaginal assessment remain uncertain, seek a tertiary-center second opinion and classify the pregnancy as monochorionic if uncertainty persists.

• A would show the lambda sign.
• C would show no dividing membrane at all.
• D is backwards: chorionicity is most reliable in the first trimester.

Takeaway: T sign means monochorionic diamniotic; lambda sign means dichorionic diamniotic. Decide early.

Source: ISUOG Practice Guidelines (updated): role of ultrasound in twin pregnancy, 2025, PDF pp. 2–3, chorionicity assessment, Figure 1 and the uncertainty pathway.

Answer: C. Current terminology has two categories. Placenta previa means placental tissue covers the internal os. A low-lying placenta has its edge less than 2 cm from the os without covering it. Transvaginal imaging is preferred for this measurement.

• A requires the placenta to cover the os.
• B is wrong: an edge less than 2 cm from the os isn't normal positioning.
• D is about fetal vessels over the os, not the placental edge.

Takeaway: Covering the os means previa; less than 2 cm away without covering means low-lying.

Source: RCOG Green-top Guideline 27a, fifth edition (2026), “Key recommendations: Placenta Praevia” and transvaginal ultrasound assessment.

Answer: A. Vasa previa is unprotected fetal vessels running over or very near the internal os. It's usually associated with a velamentous cord insertion or a succenturiate or bilobed placenta. It's diagnosed with transvaginal color and pulsed Doppler, and a fetal arterial waveform confirms the vessel is fetal. These vessels can rupture, so the finding is reported promptly.

• B is the cord lying below the presenting part. It can move, unlike vessels fixed in the membranes.
• C inserts at the placental edge, not into the membranes.
• D would show a maternal venous signal.

Takeaway: Velamentous insertion near the os means sweeping it with color Doppler for vasa previa.

Source: SMFM Consult Series #37, vasa previa, definition, types and diagnosis (2015, reaffirmed 2024).

Answer: D. These are classic signs of placenta accreta spectrum (PAS). A major risk factor is prior cesarean delivery combined with a previa, and the risk climbs with each additional cesarean.

• A may show a retroplacental or marginal collection, which can be subtle.
• B is a discrete vascular mass within the placenta.
• C is a rolled, thickened placental edge.

Takeaway: Previa over a cesarean scar means hunting for lacunae, loss of the clear zone and an abnormal bladder interface.

Source: ACOG/SMFM Obstetric Care Consensus No. 7, Placenta Accreta Spectrum (2018), PDF p. 2, “Risk Factors” and “Diagnosis.” ISUOG, Placental chorangioma, PDF p. 1 (updated March 2025); ISUOG, Placental masses, variants and lesions, PDF p. 1, circumvallate placenta (updated September 2023); RadioGraphics, Imaging of Antepartum and Postpartum Hemorrhage (2024), Figures 2 and 4.

Answer: B. Gastroschisis is a full-thickness defect beside the umbilicus, usually to the right of a normal cord insertion, with uncovered bowel floating in amniotic fluid. Aneuploidy is uncommon.

• A is midline and membrane-covered, with the cord inserting on the sac. It carries a much higher association with aneuploidy and with syndromes such as Beckwith-Wiedemann.
• C is normal during early development and resolves by about 12 weeks.
• D is skin-covered and doesn't produce free-floating bowel.

Takeaway: Gastroschisis: right of the cord, no membrane. Omphalocele: midline, membrane, cord on the sac.

Source: ISUOG gastroschisis counseling template, PDF pp. 1–2; ISUOG, Omphalocele, “What is an Omphalocele?” and “How does an Omphalocele happen?” (updated December 2024).

Answer: C. The lemon sign (frontal scalloping), the banana sign (curved cerebellum) and a small posterior fossa are the cranial clues to open spina bifida with Chiari II. The next step is to examine the whole spine in three planes. The lemon sign usually fades after about 24 weeks.

• A is the opposite in the posterior fossa: it's classically enlarged, with an abnormal vermis.
• B is failed division of the forebrain, such as a single ventricle or fused thalami.
• D can give "teardrop" ventricles and an absent cavum septi pellucidi, not the lemon and banana signs.

Takeaway: Lemon plus banana means checking the spine.

Source: EFSUMB, Typical ultrasound features in open spina bifida (January 2022), image findings and discussion; Van den Hof et al., AJOG 1990, abstract on gestational changes in the lemon sign; ISUOG, Dandy-Walker complex, definition and pathology.

Answer: A. Ventriculomegaly is an atrial width of 10 mm or more. SMFM grades it as mild at 10–12 mm, moderate at 13–15 mm, and severe above 15 mm.

• B is wrong: 11 mm is above the 10 mm cutoff.
• C starts at 13 mm.
• D is above 15 mm.

Takeaway: 10 / 13 / over 15 mm are the mild, moderate and severe thresholds.

Source: SMFM Consult Series #45, mild fetal ventriculomegaly (reaffirmed 2024), severity categories.

Answer: D. About 85% of diaphragmatic hernias are left-sided. Abdominal contents, classically the stomach, sit in the chest at the level of the four-chamber view and push the heart to the right. Also note whether there's a stomach below the diaphragm and whether liver has herniated.

• A is an echogenic or cystic lung mass. It can shift the heart, but it isn't the stomach.
• B is anechoic fluid outlining the lung.
• C is a discrete cyst arising from the developing airway, not the stomach.

Takeaway: Stomach beside the heart means CDH until proven otherwise.

Source: ISUOG teaching material on congenital diaphragmatic hernia, PDF pp. 4–9, left-sided CDH with stomach displacement; ISUOG, Lung cysts, “What are Lung Cysts?” (updated February 2024). ISUOG Basic Training: Examining fetal anatomy from longitudinal sections, PDF p. 35, left-sided frequency; ISUOG Basic Training: Assessing the neck and chest, PDF pp. 23–27 and 32, fluid, cysts and intrathoracic stomach.

Answer: B. The "double bubble" is the stomach plus a dilated proximal duodenum. With polyhydramnios, it strongly suggests duodenal atresia, although other causes of duodenal obstruction can look similar. About one-third of affected fetuses have trisomy 21, so look carefully for other markers.

• A classically shows a small or absent stomach with polyhydramnios, not a double bubble.
• C usually shows several dilated loops.
• D is a cyst near the porta hepatis that doesn't connect to the stomach.

Takeaway: Double bubble suggests duodenal obstruction, often atresia; think trisomy 21.

Source: ISUOG Basic Training: Examining the abdomen and anterior abdominal wall, PDF pp. 18–21, esophageal atresia, duodenal atresia and dilated bowel; ISUOG, Duodenal obstruction, causes and chromosomal association. ISUOG, Choledochal cyst, definition (updated December 2024); ESR ECR2021, Choledochal cysts in children, “Diagnosis,” porta-hepatis and biliary-tree relationship.

Answer: C. By 20 weeks, fetal urine is a major source of amniotic fluid. Absent kidneys and renal arteries, a bladder that never fills, and anhydramnios support bilateral renal agenesis. Prolonged anhydramnios can cause Potter sequence with severe pulmonary hypoplasia. The adrenal glands can look like kidneys (the "lying-down adrenal" sign), which is why the Doppler check matters.

• A typically causes a distended bladder with a "keyhole" urethra.
• B leaves one working kidney, so fluid and the bladder are usually preserved.
• D can cause low fluid, but it doesn't explain absent renal tissue and renal arteries.

Takeaway: Absent kidneys, no bladder filling and anhydramnios support bilateral renal agenesis.

Source: SMFM Fetal Anomalies Consult Series #4: Genitourinary anomalies (2021), PDF pp. 27–29, “Renal agenesis,” ultrasound findings and differential diagnosis.

Answer: A. At 19 weeks in monochorionic diamniotic twins, the donor's deepest pocket of 2 cm or less and the recipient's of 8 cm or more meet the fluid criteria for twin-twin transfusion syndrome (TTTS). An absent donor bladder is a Quintero stage-II feature; Doppler findings, hydrops or fetal demise can indicate a higher stage.

• B shows a large middle cerebral artery Doppler mismatch (one anemic twin, one polycythemic) without the fluid discordance.
• C involves an acardiac twin perfused by a "pump" twin.
• D is identified through fetal growth criteria, not this oligo/poly fluid pattern alone.

Takeaway: At 19 weeks in monochorionic diamniotic twins, oligo/poly (2 cm or less vs 8 cm or more) means TTTS.

Source: ISUOG twin-pregnancy guideline (2025), PDF p. 14, TTTS diagnosis and Table 1 (Quintero staging).

Answer: D. Normally one umbilical artery runs on each side of the bladder. Confirming only one supports a single umbilical artery (SUA). Associated structural abnormalities most often involve the heart or kidneys, so a careful survey matters. An isolated SUA does not by itself imply aneuploidy, but later assessment of fetal growth is still recommended.

• A is wrong: one vessel next to the bladder isn't normal.
• B is wrong: SUA by itself isn't a reason to deliver.
• C isn't the relevant next step for this finding.

Takeaway: One artery by the bladder means looking hard at the heart and kidneys.

Source: SMFM Consult Series #57 (2021, reaffirmed 2025), recommendation 11; full guideline, PDF pp. 6–7, single umbilical artery.

Answer: B. SMFM defines polyhydramnios in a singleton pregnancy as an amniotic fluid index (AFI) of 24 cm or more, or a deepest vertical pocket of 8 cm or more. Most mild cases are idiopathic. The main identifiable causes are maternal diabetes and fetal anomalies, especially gastrointestinal obstruction or problems with swallowing.

• A is wrong: 26 cm is above the threshold.
• C is the opposite finding: too little amniotic fluid.
• D is wrong: "always" is false, because many cases are idiopathic.

Takeaway: AFI of 24 cm or more, or deepest pocket of 8 cm or more, means polyhydramnios.

Source: SMFM Consult Series #46, polyhydramnios, opening explanation and recommendation 1 (reaffirmed 2024).

Answer: C. SMFM defines a midtrimester transvaginal cervical length of 25 mm or less as a short cervix in this setting. Measure the closed part of the canal. Funneling gets described, but cervical length is what classifies the finding.

• A is wrong: 22 mm is under 25 mm.
• B is wrong: cervical length can be assessed at the midtrimester scan.
• D is wrong: funneling alone doesn't establish cervical insufficiency.

Takeaway: In this setting, 25 mm or less is a short cervix.

Source: SMFM Consult Series #70, short cervix (2024), recommendation 2; ISUOG guideline: ultrasound in the prediction of spontaneous preterm birth (2022), PDF p. 3, Table 1 and Figure 1; p. 6, funneling excluded from cervical length.

Answer: A. In d-transposition, the aorta comes off the right ventricle and the pulmonary artery off the left, so the vessels run in parallel instead of crossing. The four-chamber view is usually normal. That's why outflow tract and three-vessel views are part of the fetal heart survey.

• B shows a ventricular septal defect with an overriding aorta and right ventricular outflow obstruction.
• C shows an obviously abnormal four-chamber view with a small left ventricle.
• D shows an abnormal four-chamber view with a common atrioventricular valve.

Takeaway: Parallel great arteries with the aorta from the right ventricle and pulmonary artery from the left ventricle point to TGA.

Source: ISUOG VISUOG, Transposition of the great arteries, “Description of sonographic findings” and “Differential diagnosis” (August 2023).

Answer: D. SMFM defines fetal growth restriction (FGR) as an EFW or an AC below the 10th percentile for gestational age. Either one alone qualifies, and here both do. Umbilical artery Doppler is the standard next assessment.

• A is wrong: a normal head doesn't cancel a small abdomen. Growth restriction can be head-sparing.
• B is wrong: an EFW below the 3rd percentile marks severe FGR, but the definition starts at the 10th.
• C is wrong: second- and third-trimester biometry can identify a small fetus; serial measurements assess growth over time.

Takeaway: EFW or AC under the 10th percentile is FGR (SMFM).

Source: SMFM Consult Series #52, fetal growth restriction, recommendations 1 and 9 (reaffirmed 2024); full guideline, PDF pp. 2–4; ISUOG fetal biometry and growth guideline (2019), introduction, distinction between fetal size and growth.

Answer: D. Add the two tissue layers and leave out the fluid: 2.2 + 1.8 = 4.0 mm.

• A includes the fluid (2.2 + 1.8 + 3.0).
• B averages the layers instead of adding them.
• C records the fluid alone.

Takeaway: With fluid in the cavity, measure each layer and add them; never include the fluid.

Source: AIUM gynecologic ultrasound image companion, PDF p. 35, “Endometrium” (the two tissue layers are measured without the intervening fluid).

Answer: B. MSD is the average of three orthogonal sac dimensions: (14 + 17 + 20) ÷ 3 = 17 mm. An MSD of 17 mm without an embryo does not meet the 25 mm size-based criterion for early pregnancy loss. Prior scan findings and follow-up timing also matter; this calculation alone does not establish the outcome.

• A has the right math but the wrong interpretation.
• C adds the dimensions without dividing.
• D uses the largest single dimension instead of the mean.

Takeaway: MSD = (L + W + H) ÷ 3.

Source: ISUOG Basic Training: 4–10-week findings, PDF p. 11, mean sac diameter; ISUOG teaching material on miscarriage and pregnancies of uncertain viability, PDF p. 6, inner-border measurements; SRU first-trimester lexicon (2024), “Diagnostic of EPL.”

Answer: C. BPD is measured in the transthalamic plane: the thalami and cavum septi pellucidi are visible, both hemispheres look symmetric, and the cerebellum is out of the plane. ISUOG prefers outer-to-outer caliper placement, though some reference charts use outer-to-inner. Match your department's chart.

• A is the transcerebellar plane, used for the cerebellum, cisterna magna and nuchal fold.
• B is the transventricular plane, used to measure the atrium.
• D is wrong because BPD is a transverse measurement.

Takeaway: BPD uses the thalami and CSP, with no cerebellum in the plane.

Source: ISUOG Practice Guidelines (updated): routine mid-trimester fetal ultrasound, 2022, PDF p. 4, BPD section.

Answer: A. The AC plane is a true transverse section through the stomach and the umbilical vein at the portal sinus, with the kidneys out of plane. The ellipse goes on the outer skin surface.

• B is too low: visible kidneys mean the section is caudal to the correct plane.
• C is too low and measures inside the skin line, so it undermeasures.
• D is oblique: a long segment of umbilical vein means the section isn't transverse.

Takeaway: AC is stomach plus portal sinus, no kidneys, calipers on the skin.

Source: ISUOG Practice Guidelines (updated): routine mid-trimester fetal ultrasound, 2022, PDF pp. 4–5, AC section.

Answer: D. For standard first-trimester NT screening, the CRL range is 45–84 mm, about 11+0 to 13+6 weeks. A raised NT is linked with aneuploidy and with major congenital heart defects, so an elevated value leads to further evaluation.

• A is too early.
• B is past the window.
• C is wrong: neutral head position is required, but the CRL window still applies.

Takeaway: NT is valid at a CRL of 45–84 mm.

Source: ISUOG Practice Guidelines (updated): performance of the 11–14-week scan, 2023, CRL and NT sections; Fetal Medicine Foundation, Nuchal translucency, NT measurement window.

Answer: B. Cephalic index = BPD ÷ OFD × 100 = 72 ÷ 96 × 100 = 75.0. Interpret the index against a reference range that uses the same measurement technique. An unusual head shape is the reason head circumference is more reliable than BPD for dating in those cases.

• A divides the wrong way (OFD ÷ BPD).
• C divides the measurements but omits multiplication by 100.
• D subtracts the measurements instead of dividing them.

Takeaway: CI = BPD ÷ OFD × 100.

Source: ISUOG Practice Guidelines (updated): routine mid-trimester fetal ultrasound, 2022, PDF p. 4, BPD, cephalic index, head shape and reference-chart technique.

Answer: C. Between 15 and 20 weeks, a nuchal fold of 6 mm or more is thickened. It's measured from the outer edge of the occipital bone to the outer edge of the skin. It's a recognized second-trimester soft marker for Down syndrome, so it's reported for the clinician to interpret alongside prior screening results and the rest of the anatomy survey.

• A is wrong: 7 mm is above the 6 mm threshold.
• B confuses it with NT; the nuchal fold is a second-trimester measurement.
• D is wrong: nuchal fold and NT differ in timing, technique and thresholds.

Takeaway: A nuchal fold of 6 mm or more at 15–20 weeks is thickened.

Source: SMFM Consult Series #57, isolated soft markers (2021, reaffirmed 2025), recommendation 8; full guideline, PDF p. 10, nuchal-fold technique and interpretation.

Answer: A. Each BPP component scores either 2 or 0, with no partial credit. Breathing earns 2 only with at least one episode of rhythmic breathing lasting 30 seconds or more within 30 minutes. One 20-second episode scores 0.

• B is wrong: there are no 1-point scores.
• C is wrong: the 30-second requirement wasn't met.
• D is wrong: the nonstress test is a separate component, and the four ultrasound components are scored on their own.

Takeaway: Each BPP component scores 2 or 0, and breathing needs one episode of 30 seconds or more within 30 minutes.

Source: Mayo Clinic, Antenatal Testing teaching presentation, PDF p. 15, “Biophysical Profile” scoring table.

Answer: D. Chorionic villus sampling (CVS) is typically done at about 10–13 weeks. The sonographer's role is real-time guidance plus documentation of placental location, the needle or catheter path, and fetal heart activity before and after the procedure.

• A is standard at 15 weeks or later; amniocentesis at 10–13 weeks isn't recommended.
• B is a later-pregnancy procedure, for example in suspected fetal anemia.
• C is a gynecologic cavity exam, not a pregnancy procedure.

Takeaway: CVS is done at 10–13 weeks; amniocentesis at 15 weeks or later.

Source: ACOG Practice Bulletin 162, Prenatal Diagnostic Testing for Genetic Disorders (May 2016), PDF p. 4, procedure timing; ISUOG invasive-procedures guideline (2016), PDF pp. 3 and 7, ultrasound guidance and assessment.

Answer: C. These findings suggest a ruptured ectopic pregnancy with hemoperitoneum in an unstable patient. SDMS clinical standards direct the sonographer to notify the appropriate healthcare provider when immediate medical attention may be needed, following facility policy. Ectopic pregnancy, ovarian torsion and fetal demise all appear in the outline's list of findings that require immediate action.

• A delays urgent care.
• B is outside the sonographer's scope: diagnosis and treatment decisions belong to the physician.
• D leaves a possibly unstable patient alone.

Takeaway: For an unstable patient with critical findings, notify now and stay with the patient.

Source: SDMS Scope of Practice and Clinical Standards (2024), PDF pp. 6 and 11, interpretation responsibilities and Standards 1.5.4 and 1.6.3; ARDMS OB/GYN v24.1 outline, objective 4.A.4.

Answer: B. AIUM recommends documenting early heart rate with M-mode or B-mode (2D) imaging, keeping the thermal index low (preferably 0.7 or less), and not using pulsed Doppler routinely. AIUM also advises monitoring the soft-tissue thermal index (TIs) before 10 weeks and the bone thermal index (TIb) from 10 weeks on.

• A uses a higher-energy mode when a lower-exposure method does the job, which goes against ALARA ("as low as reasonably achievable").
• C adds unnecessary dwell time and exposure.
• D deliberately maximizes output, the opposite of ALARA.

Takeaway: For early heart rate, use M-mode or a 2D clip and skip routine spectral Doppler.

Source: AIUM, Prudent Use and Safety of Diagnostic Ultrasound in Pregnancy (2020), “Fetal Heart Rate Evaluation.”

Answer: A. An abnormal umbilical artery waveform reflects placental insufficiency, and absent or reversed end-diastolic velocity reflects significant placental deterioration. It changes delivery timing, so it's communicated promptly. Before reporting, confirm your technique: low wall filter, a free cord loop, and no fetal breathing.

• B is wrong: normal pregnancy shows increasing diastolic flow as placental resistance falls.
• C is wrong: a high wall filter can mimic lost diastolic flow, so check your settings. A true finding is never simply ignored.
• D is assessed with middle cerebral artery peak systolic velocity, not umbilical artery diastolic flow.

Takeaway: Absent or reversed end-diastolic velocity means significant placental insufficiency.

Source: SMFM Consult Series #52, fetal growth restriction, umbilical artery Doppler recommendations; full guideline, PDF p. 8, absent/reversed flow; ISUOG Doppler velocimetry technical guideline (2013), PDF pp. 1–2 and 4, acquisition technique.

Answer: D. An MCA peak systolic velocity above 1.5 MoM identifies a fetus at significant risk of severe anemia. Anemic blood is thinner and the circulation is hyperdynamic, so velocity rises. SMFM technique: sample the MCA close to its origin from the internal carotid, with the angle of insonation as close to 0° as possible.

• A is backwards: anemia raises the velocity.
• B is wrong: 60° is a habit from vascular studies, but this measurement needs an angle near 0°.
• C is wrong: sample near the origin.

Takeaway: MCA peak systolic velocity above 1.5 MoM means suspect severe fetal anemia; keep the angle near 0° and sample near the origin.

Source: SMFM Clinical Guideline #8, the fetus at risk for anemia (2015), PDF pp. 1 and 4–5, threshold and MCA technique; Haugen et al., Ultrasonographic monitoring of pregnancies complicated by red blood cell alloimmunization (2002), introduction, cardiac output and blood viscosity.