Maternal-Fetal Medicine Practice Questions

Q: A patient with a known marginal placenta presents for follow-up. On ultrasound, a 4 x 4 cm placental mass is noted invading into the urinary bladder. What is the most likely diagnosis?

Placenta percreta. ***Placenta percreta*** - This is the most severe form of the **placenta accreta spectrum**, where the placental villi penetrate through the entire uterine wall, including the **serosa**, and invade adjacent organs. - The ultrasound finding of a placental mass invading the **urinary bladder** is the classic presentation of **placenta percreta**. *Placenta previa* - This term describes the location of the placenta, where it partially or completely covers the **internal cervical os**. It does not describe the depth of invasion. - Although **placenta previa** is a significant risk factor for placenta accreta spectrum disorders, the invasion into the bladder points to a specific diagnosis of abnormal adherence, not just location. *Placenta increta* - In **placenta increta**, the placental villi invade into the **myometrium** (uterine muscle) but do not penetrate through to the serosa or adjacent organs. - This represents the intermediate form of the accreta spectrum, more severe than accreta but less severe than percreta. *Placenta accreta* - In **placenta accreta**, the placental villi are abnormally attached to the **myometrium**, but they do not invade the uterine muscle itself. This is the least invasive form of the spectrum. - The finding of invasion into the **urinary bladder** rules out simple accreta, as this requires penetration through the entire myometrium and serosa, which is characteristic of percreta.

Q: Fetal anaemia is primarily determined by Doppler assessment of which artery?

Middle cerebral artery. ***Middle cerebral artery***- The **Middle Cerebral Artery (MCA) peak systolic velocity (PSV)** is the most reliable non-invasive method for detecting moderate to severe fetal anemia.- An elevated MCA-PSV indicates increased cerebral blood flow velocity due to reduced blood viscosity (from anemia) and the **brain-sparing effect**.- *Umbilical artery*- Doppler assessment of the umbilical artery primarily evaluates **placental vascular resistance** (e.g., in fetal growth restriction) using indices like the resistive index (RI) or pulsatility index (PI).- While abnormalities like absent or reversed diastolic flow indicate severe placental insufficiency, they are not the primary diagnostic measure for fetal anemia.- *Ductus venosus*- Ductus venosus Doppler evaluates **fetal cardiac function** and is critical in assessing fetal compromise, especially in conditions leading to hydrops fetalis.- Although reverse flow can be an indicator of severe compromise and impending heart failure (potentially caused by severe anemia), it is secondary to MCA-PSV for the specific diagnosis of anemia.- *Uterine artery*- Uterine artery Doppler assesses **maternal placental perfusion** and resistance, primarily used for screening and monitoring conditions like **preeclampsia** and **fetal growth restriction**.- It measures maternal blood flow to the placenta and has no direct correlation or role in determining the severity of fetal anemia.

Q: A 29-year-old woman presents with abdominal pain, vaginal bleeding, and a history of amenorrhea for 6 weeks. Transvaginal ultrasound does not show an intrauterine gestational sac or features suggestive of ectopic pregnancy. Her serum $\beta$-hCG is 1,200 IU/L, which is below the discriminatory zone. What is the next step in management?

Repeat $\beta$-hCG after 48 hours. ***Repeat $\beta$-hCG after 48 hours*** - In a pregnancy of unknown location (PUL) with **β-hCG below the discriminatory zone** (1,500-2,000 IU/L), ultrasound cannot reliably visualize an intrauterine pregnancy - **Serial β-hCG monitoring at 48-hour intervals** is the standard approach to determine pregnancy viability and location - Expected β-hCG patterns help guide management: - **Rise >53% in 48 hours**: Suggests viable intrauterine pregnancy → repeat ultrasound when β-hCG reaches discriminatory zone - **Rise 50% in 48 hours**: Suggests spontaneous miscarriage → monitor to zero - Patient is **hemodynamically stable**, so expectant management with close monitoring is appropriate *Dilatation and curettage* - Premature intervention without knowing β-hCG trend - Reserved for cases where β-hCG plateaus or rises abnormally, suggesting either ectopic or abnormal intrauterine pregnancy - May be used for histological diagnosis (presence of chorionic villi confirms intrauterine pregnancy) *Methotrexate therapy* - Cannot be administered without **confirmed diagnosis of ectopic pregnancy** - Requires meeting specific criteria: hemodynamic stability, unruptured ectopic, β-hCG typically <5,000 IU/L, no fetal cardiac activity - Inappropriate when pregnancy location is unknown *Laparoscopy* - Too invasive as initial management for a **stable patient** - Reserved for hemodynamically unstable patients with suspected ruptured ectopic pregnancy - May be indicated later if ectopic pregnancy is confirmed and meets surgical criteria

Q: Fetal anaemia is monitored by?

MCA-PSV. ***MCA-PSV*** - **Middle Cerebral Artery-Peak Systolic Velocity (MCA-PSV)** is a non-invasive Doppler ultrasound method to assess for fetal anemia. It measures the peak velocity of blood flow in the fetal middle cerebral artery. - In anemic fetuses, blood viscosity decreases, leading to increased cardiac output and higher cerebral blood flow velocity. A value greater than **1.5 Multiples of the Median (MoM)** for gestational age is highly predictive of moderate to severe fetal anemia. *Maternal blood* - Maternal blood testing, such as the **Indirect Coombs Test (ICT)**, is used to detect maternal antibodies against fetal red blood cells, indicating maternal sensitization and risk of fetal hemolysis. - While a rising titer suggests an increased risk, it does not directly quantify the severity of anemia in the fetus itself; it serves as a screening tool to identify pregnancies needing closer surveillance. *Fetal blood* - Fetal blood sampling, performed via **cordocentesis**, is the gold standard for diagnosing and quantifying the degree of fetal anemia by directly measuring fetal hemoglobin. - However, it is an invasive procedure with significant risks (e.g., fetal loss, hemorrhage) and is reserved for confirming severe anemia indicated by non-invasive tests like MCA-PSV, or for therapeutic intervention like intrauterine transfusion. *Amniocentesis* - Historically, amniocentesis was used to measure the level of bilirubin in the amniotic fluid (spectrophotometry at ΔOD450) as an indirect marker of hemolysis. - This invasive method has been largely replaced by the non-invasive, safer, and more accurate MCA-PSV Doppler assessment for monitoring fetal anemia.

Q: Which of the following drugs is not given for hypertension in pregnancy?

Enalapril. ***Correct: Enalapril*** - **Enalapril** is an **Angiotensin-Converting Enzyme (ACE) inhibitor** which is strictly **contraindicated** throughout pregnancy, particularly during the second and third trimesters - The use of ACE inhibitors is associated with severe **fetal renal dysfunction**, resulting in **oligohydramnios**, **pulmonary hypoplasia**, and **fetal death** - ACE inhibitors are **NOT given** for hypertension in pregnancy due to these serious teratogenic effects *Incorrect: Methyldopa* - **Methyldopa**, a centrally acting **alpha-2 agonist**, is historically considered the first-line and safest drug for treating chronic hypertension during pregnancy - Its extensive use has demonstrated a favorable long-term safety profile for the development of the child - It operates by reducing **sympathetic outflow** from the central nervous system, thereby lowering peripheral vascular resistance *Incorrect: Labetalol* - **Labetalol** is a combined **alpha-1 and non-selective beta-blocker** and is a primary first-line choice for treating both chronic and **acute severe hypertension** in pregnant women - It is rapidly effective and safe, maintaining adequate **placental perfusion** - It exerts its antihypertensive effects by acting as a competitive antagonist at both adrenergic receptors *Incorrect: Nifedipine* - **Nifedipine** is a **dihydropyridine calcium channel blocker** frequently used for managing chronic hypertension and treating acute severe hypertension or **preeclampsia** in pregnancy - It is generally considered safe and effective - Its most common use is often an alternative first-line agent to Labetalol or for the management of hypertensive crises via its extended-release formulation

Q: Which findings are most suggestive of tubal pregnancy?

Adnexal mass with empty uterus and fluid in pelvis. ***Adnexal mass with empty uterus and fluid in pelvis***- The visualization of an **adnexal mass** (corresponding to the tubal gestation) and an **empty uterus** confirms the diagnosis of an ectopic pregnancy.- The presence of **free fluid in the pelvis** (hemoperitoneum) is highly suggestive of a ruptured or leaking tubal pregnancy, representing the most urgent presentation.*Ovarian mass with single layer of endometrium*- An **ovarian mass** suggests pathology involving the ovary itself, such as an ovarian ectopic pregnancy or a cyst, rather than the most common site, the fallopian tube.- The **single layer of endometrium** (thin decidual reaction) may occur in ectopic pregnancy due to insufficient hormonal stimulus but is not sufficient evidence for a tubal location.*Adnexal mass with empty uterus*- While this constellation of findings definitely suggests an **ectopic pregnancy**, it is often indicative of an early and **unruptured** tubal pregnancy.- Lacking **free fluid (blood)** in the pelvis makes this option less suggestive of advanced or complicated tubal pregnancy compared to the correct option.*Trilayer endometrium without adnexal mass*- A **trilayer endometrium** is a typical ultrasound finding during the proliferative phase, or it may be seen in a developing intrauterine pregnancy (IUP).- The absence of an **adnexal mass** essentially excludes the possibility of a tubal ectopic pregnancy.

Q: Identify the given image of the placenta previa.

Marginal. ***Marginal*** - The image illustrates **marginal placenta previa**, where the edge of the placenta is at the margin of the **internal cervical os** but does not cover it. - This position can lead to significant bleeding as the cervix dilates and effaces during labor, potentially tearing the placental edge. *Low lying* - A **low-lying placenta** is when the placental edge is implanted in the lower uterine segment, within **2 cm** of the internal os, but not reaching it. - The image clearly shows the placenta is directly at the edge of the os, which is characteristic of marginal, not low-lying previa. *Incomplete* - **Incomplete** or **partial placenta previa** occurs when the placenta partially covers the internal cervical os. - In the given diagram, the cervical os is not covered at all; the placenta only abuts its margin. *Complete* - **Complete placenta previa** is diagnosed when the placenta entirely covers the **internal cervical os**, obstructing the birth canal. - This is the most severe type and is an absolute indication for a **cesarean section**, whereas the image shows an uncovered os.

Q: Identify the given image of the placenta previa. ![img-50.jpeg](img-50.jpeg)

Marginal. ***Marginal*** - In **marginal placenta previa**, the edge of the placenta is at the margin of the **internal cervical os** but does not cover it, which is consistent with the depiction in the image. - This type can lead to **painless, bright red vaginal bleeding**, particularly in the third trimester as the cervix begins to efface and dilate, causing separation of the placental edge. *Low lying* - A **low-lying placenta** is implanted in the lower uterine segment, and its edge is within **2 cm** of the internal os but does not reach the os itself. - The image shows the placenta directly abutting the os, which distinguishes it from a low-lying placenta where there would be a gap. *Incomplete* - **Incomplete** or **partial placenta previa** occurs when the placenta partially covers the internal cervical os. - The provided image clearly shows the cervical os is not covered by any placental tissue, ruling out this diagnosis. *Complete* - In **complete placenta previa**, the placenta entirely covers the internal cervical os, obstructing the birth canal. - This is the most severe form and is not represented in the image, as the os is visibly unobstructed.

Q: Which of the following is the most common location of implantation in ectopic pregnancy? ![img-40.jpeg](img-40.jpeg)

A. ***A*** - Label A points to the **fallopian tube**, which is the site of over 95% of all ectopic pregnancies. The most common specific location within the tube is the **ampulla** (approximately 80% of tubal ectopics). - Risk factors such as **pelvic inflammatory disease (PID)**, previous tubal surgery, or endometriosis can damage the fallopian tube, impeding the transit of the fertilized ovum to the uterus. *D* - Label D indicates the **uterus**, which is the normal site for implantation in a healthy, **intrauterine pregnancy**. - By definition, an ectopic pregnancy is one that implants *outside* the uterine cavity, making this location incorrect. *B* - Label B indicates the **ovary**. An **ovarian ectopic pregnancy** is a rare form of ectopic implantation, constituting about 3% of cases. - This occurs if the egg is fertilized and implants on or within the ovary itself, before it enters the fallopian tube. *C* - Label C points to the **cervix**. A **cervical pregnancy** is a very rare type of ectopic pregnancy, accounting for less than 1% of cases. - This location is particularly dangerous due to a high risk of life-threatening **hemorrhage** because of the cervix's rich vascular supply.

Question 1

A patient with a known marginal placenta presents for follow-up. On ultrasound, a 4 x 4 cm placental mass is noted invading into the urinary bladder. What is the most likely diagnosis?

Accepted Answer

Placenta percreta

Answer

Placenta accreta

Answer

Placenta previa

Answer

Placenta increta

Question 2

Fetal anaemia is primarily determined by Doppler assessment of which artery?

Accepted Answer

Middle cerebral artery

Answer

Umbilical artery

Answer

Uterine artery

Answer

Ductus venosus

Question 3

A 28-year-old pregnant woman at 33 weeks gestation presents for a routine prenatal visit. She reports decreased fetal movements over the past two days. She has a history of gestational diabetes, and her pregnancy has been otherwise uneventful. The doctor decides to perform antepartum fetal surveillance. Which of the following is the most appropriate initial test to assess the fetal well-being in this scenario?

Accepted Answer

Non Stress test

Answer

Biophysical profile

Answer

Amniotic fluid index

Answer

Contraction Stress test

Question 4

A 29-year-old woman presents with abdominal pain, vaginal bleeding, and a history of amenorrhea for 6 weeks. Transvaginal ultrasound does not show an intrauterine gestational sac or features suggestive of ectopic pregnancy. Her serum $\beta$-hCG is 1,200 IU/L, which is below the discriminatory zone. What is the next step in management?

Accepted Answer

Repeat $\beta$-hCG after 48 hours

Answer

Dilatation and curettage

Answer

Methotrexate therapy

Answer

Laparoscopy

Question 5

Fetal anaemia is monitored by?

Accepted Answer

MCA-PSV

Answer

Amniocentesis

Answer

Maternal blood

Answer

Fetal blood

Question 6

Which of the following drugs is not given for hypertension in pregnancy?

Accepted Answer

Enalapril

Answer

Nifedipine

Answer

Methyldopa

Answer

Labetalol

Question 7

Which findings are most suggestive of tubal pregnancy?

Accepted Answer

Adnexal mass with empty uterus and fluid in pelvis

Answer

Trilayer endometrium without adnexal mass

Answer

Ovarian mass with single layer of endometrium

Answer

Adnexal mass with empty uterus

Question 8

Identify the given image of the placenta previa.

Accepted Answer

Marginal

Answer

Complete

Answer

Low lying

Answer

Incomplete

Question 9

Identify the given image of the placenta previa. ![img-50.jpeg](img-50.jpeg)

Accepted Answer

Marginal

Answer

Incomplete

Answer

Low lying

Answer

Complete

Question 10

Which of the following is the most common location of implantation in ectopic pregnancy? ![img-40.jpeg](img-40.jpeg)

Accepted Answer

A

Answer

D

Answer

B

Answer

C

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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