Maternal-Fetal Medicine Practice Questions

Q: Large placenta is seen in all of the following conditions except?

Intrauterine Growth Restriction (IUGR). **Explanation:** The size and weight of the placenta are generally proportional to the size of the fetus. A **Large Placenta (Placentomegaly)** is typically defined as a placental thickness >4 cm or a weight exceeding the 90th percentile for gestational age. **1. Why IUGR is the correct answer:** In **Intrauterine Growth Restriction (IUGR)**, particularly placental-mediated IUGR (Type 2/Asymmetrical), there is **uteroplacental insufficiency**. This is characterized by poor trophoblastic invasion and reduced surface area for nutrient exchange, leading to a **small, shrunken, and infarcted placenta**. Since the question asks for the condition where a large placenta is *not* seen, IUGR is the correct choice. **2. Why the other options are incorrect:** * **Syphilis:** Congenital syphilis causes chronic villitis and edema of the placental villi, leading to a significantly enlarged, "pale," and "greasy" placenta. * **Cytomegalovirus (CMV) & Rubella:** These are part of the **TORCH infections**. Chronic intrauterine infections lead to inflammatory infiltration (villitis) and compensatory hyperplasia of the placental tissue, resulting in placentomegaly. **NEET-PG High-Yield Pearls:** * **Causes of Large Placenta:** Diabetes Mellitus (most common), Hydrops Fetalis (Immune/Non-immune), Syphilis, TORCH infections, Multiple gestations, and Chorioangioma. * **Causes of Small Placenta:** IUGR, Pre-eclampsia, Chronic Hypertension, and Chromosomal anomalies (e.g., Trisomy 18). * **Normal Placental Weight:** Approximately 1/6th of the baby's weight at term (approx. 500g). * **Placentomegaly on Ultrasound:** A thickness of **>40 mm** is a key diagnostic marker.

Q: Doppler ultrasonography in Intrauterine Growth Restriction (IUGR) and Preeclampsia shows a notch in which artery?

Uterine artery. **Explanation:** The correct answer is **B. Uterine artery**. In a normal pregnancy, trophoblastic invasion of the spiral arteries converts them from high-resistance, low-flow vessels into low-resistance, high-flow vessels. This process occurs in two waves (at 10–12 weeks and 16–20 weeks). If this invasion is defective, as seen in **Preeclampsia and Fetal Growth Restriction (FGR/IUGR)**, the uterine artery remains a high-resistance vessel. On Doppler, this high resistance manifests as an **early diastolic notch**. Persistence of this notch beyond **24 weeks** of gestation is a significant predictor of placental insufficiency, preeclampsia, and IUGR. **Analysis of Incorrect Options:** * **A. Umbilical artery:** Doppler changes here reflect fetal-placental resistance. In IUGR, we see increased resistance, reduced end-diastolic flow (REDF), or absent/reversed end-diastolic flow (AEDF/REDF), but **not** a diastolic notch. * **C. Internal iliac artery:** While the uterine artery is a branch of the internal iliac, the specific pathological changes related to placental perfusion are measured directly at the uterine artery. * **D. Vitelline artery:** This is an embryonic vessel associated with the yolk sac and is not used for monitoring IUGR or preeclampsia in clinical practice. **High-Yield Clinical Pearls for NEET-PG:** * **Uterine Artery Doppler:** Best for **screening** and predicting preeclampsia (High resistance = Notch). * **Umbilical Artery Doppler:** Best for **monitoring** a diagnosed case of IUGR and deciding the timing of delivery. * **Middle Cerebral Artery (MCA):** Shows "Brain Sparing Effect" (increased diastolic flow/low resistance) in IUGR. * **Ductus Venosus:** Abnormal flow (a-wave reversal) is a late sign of fetal cardiac failure and an indication for immediate delivery.

Q: At what gestational age should an uncomplicated triplet pregnancy be delivered?

34 weeks. **Explanation:** The timing of delivery in multiple gestations is a balance between the risks of prematurity and the increasing risk of stillbirth and placental insufficiency as the pregnancy progresses. **1. Why 34 weeks is correct:** For an **uncomplicated triplet pregnancy**, the risk of fetal demise increases significantly after 34 weeks. According to standard guidelines (ACOG and RCOG), elective delivery is recommended at **34 weeks 0 days**. At this stage, the benefits of avoiding potential intrauterine complications outweigh the neonatal risks associated with late preterm birth. Corticosteroids are typically administered prior to delivery to enhance fetal lung maturity. **2. Why the other options are incorrect:** * **35 weeks (Option B):** While only one week later, data shows a sharp rise in the risk of stillbirth in triplet pregnancies beyond the 34-week mark. * **37 weeks (Option C):** This is the recommendation for **uncomplicated twin pregnancies** (specifically dichorionic diamniotic twins). For triplets, 37 weeks is considered "post-term" due to extreme uterine distention and placental exhaustion. * **38 weeks (Option D):** This is the timing for a standard **singleton pregnancy**. Carrying triplets to this age poses a severe risk of maternal complications (preeclampsia, abruption) and fetal death. **High-Yield Clinical Pearls for NEET-PG:** * **Singleton:** 39–40 weeks. * **Twins (DCDA):** 37–38 weeks. * **Twins (MCDA):** 36–37 weeks. * **Twins (MCMA):** 32–34 weeks (delivered via Cesarean). * **Triplets:** 34 weeks. * **Mode of delivery for triplets:** Almost always **Cesarean section** due to the high risk of malpresentation and cord prolapse.

Q: What type of placenta is depicted?

Monochorionic Monoamniotic. ***Monochorionic Monoamniotic*** - Characterized by the **absence of an inter-twin dividing membrane** between the two fetuses, allowing them to share both the same **chorion** and **amniotic cavity**. - This type represents the highest risk twin pregnancy due to potential **cord entanglement** and **conjoined twinning**, occurring when embryonic division happens after day 8-13. *Monochorionic Diamniotic* - Features **two separate amniotic sacs** divided by a **thin membrane** (lambda sign absent, T-sign present), but shares a single chorion. - The presence of a **dividing membrane** between the twins would be clearly visible, distinguishing it from the monoamniotic type. *Dichorionic Diamniotic* - Shows **two separate chorions** and **two separate amniotic sacs** with a **thick dividing membrane** and characteristic **lambda sign** at the placental insertion. - Each twin has its own **placental territory** with separate vascular systems, making it the safest type of twin pregnancy. *Twin-to-twin transfusion syndrome* - This is a **complication** that can occur in monochorionic pregnancies, not a placental type itself. - Results from **unbalanced vascular anastomoses** in the shared placenta, leading to **donor-recipient** blood flow imbalance between twins.

Q: A pregnant woman, G2P1, at 35 weeks gestation complains of decreased fetal movement. What is the next step in management?

Non-stress test (NST). ### Explanation **1. Why Non-stress Test (NST) is the Correct Answer:** Decreased fetal movement (DFM) is a clinical warning sign of potential fetal compromise. The primary goal in management is to assess fetal well-being promptly using the least invasive method. The **Non-stress Test (NST)** is the standard **first-line screening tool** for evaluating fetal heart rate (FHR) reactivity in the third trimester (after 28–32 weeks). A reactive NST (two or more accelerations in 20 minutes) indicates a functional fetal brainstem and an intact autonomic nervous system, effectively ruling out immediate acidemia. **2. Analysis of Incorrect Options:** * **A. Observation:** This is inappropriate and dangerous. DFM can be a precursor to stillbirth; therefore, objective fetal surveillance is mandatory. * **C. Contraction Stress Test (CST):** This is a second-line test used when the NST is non-reactive. It involves inducing contractions (via oxytocin or nipple stimulation) to check for late decelerations. It is more time-consuming and contraindicated in certain conditions (e.g., placenta previa). * **D. Biophysical Profile Score (BPS):** While BPS is a highly accurate predictor of fetal health, it is typically reserved as a **follow-up test** if the NST is non-reactive or if the patient is high-risk. It requires ultrasound equipment and more time than a bedside NST. **3. Clinical Pearls for NEET-PG:** * **Definition of DFM:** Usually defined as <10 movements in 2 hours (Sadovsky’s method) or <3 movements in 1 hour (Cardiff "Count-to-Ten"). * **Sequence of Assessment:** DFM → Clinical History/Auscultation → **NST** → (if non-reactive) → **BPS** or CST. * **Modified BPS:** Consists of NST + Amniotic Fluid Index (AFI). This is a common high-yield alternative for rapid assessment. * **Reactive NST:** 2 accelerations of 15 bpm lasting 15 seconds in a 20-minute window (15x15 rule). For <32 weeks, use the 10x10 rule.

Q: Which of the following strategies for administering magnesium sulfate for eclampsia prophylaxis should be used in the setting of an elevated serum creatinine?

None of the above. **Explanation:** The management of magnesium sulfate ($MgSO_4$) in patients with renal impairment (elevated serum creatinine) is a high-yield topic in NEET-PG. Magnesium is almost exclusively excreted by the kidneys; therefore, in the setting of renal insufficiency, the risk of magnesium toxicity increases significantly. **Why "None of the above" is correct:** The standard protocol for eclampsia prophylaxis in patients with renal impairment (Serum Creatinine > 1.1 mg/dL) involves: 1. **Maintaining the standard loading dose:** A full loading dose (4–6g IV) is necessary to achieve therapeutic serum levels rapidly. 2. **Reducing or omitting the maintenance dose:** The maintenance infusion should be halved (to 1g/hr) or omitted entirely if the creatinine is significantly elevated, as the drug will not be cleared efficiently. **Analysis of Incorrect Options:** * **Option A & B:** A 3g loading dose is sub-therapeutic. The standard loading dose remains 4–6g regardless of renal function to ensure the patient reaches the therapeutic window (4–7 mEq/L) immediately. * **Option C:** Starting an infusion without a loading dose is dangerous in eclampsia prophylaxis, as it takes too long to reach steady-state therapeutic levels, leaving the patient at risk for seizures. **Clinical Pearls for NEET-PG:** * **Therapeutic Range:** 4–7 mEq/L (or 4.8–8.4 mg/dL). * **Monitoring:** Always monitor **Patellar reflex** (lost at 7–10 mEq/L), **Respiratory rate** (depressed at >12 mEq/L), and **Urine output** (should be >30 ml/hr). * **Antidote:** 10 ml of 10% **Calcium Gluconate** IV administered over 10 minutes. * **Renal Adjustment:** If Creatinine > 1.1 mg/dL, use a 4g loading dose and a 1g/hr maintenance dose with frequent serum level monitoring.

Question 1

Large placenta is seen in all of the following conditions except?

Accepted Answer

Intrauterine Growth Restriction (IUGR)

Answer

Syphilis

Answer

Cytomegalovirus (CMV) infection

Answer

Rubella infection

Question 2

Doppler ultrasonography in Intrauterine Growth Restriction (IUGR) and Preeclampsia shows a notch in which artery?

Accepted Answer

Uterine artery

Answer

Umbilical artery

Answer

Internal iliac artery

Answer

Vitelline artery

Question 3

At what gestational age should an uncomplicated triplet pregnancy be delivered?

Accepted Answer

34 weeks

Answer

35 weeks

Answer

37 weeks

Answer

38 weeks

Question 4

A 26-year-old primigravida with a twin gestation at 30 weeks presents for a USG. The sonogram indicates that the fetuses are both male and the placenta appears to be diamniotic and monochorionic. Twin B is noted to have oligohydramnios and to be much smaller than twin A. In this clinical scenario, all of the following are concerns for twin A except?

Accepted Answer

Anemia

Answer

Congestive heart failure (CHF)

Answer

Hydramnios

Answer

Widespread thromboses

Question 5

What type of placenta is depicted?

Accepted Answer

Monochorionic Monoamniotic

Answer

Monochorionic Diamniotic

Answer

Dichorionic Diamniotic

Answer

Twin-to-twin transfusion syndrome

Question 6

The risk of thromboembolism increases in pregnancy because:

Accepted Answer

Increased hepatic production of clotting factors

Answer

Viscosity of blood increases

Answer

Increased antithrombin III levels

Answer

Increased progesterone levels

Question 7

A pregnant woman, G2P1, at 35 weeks gestation complains of decreased fetal movement. What is the next step in management?

Accepted Answer

Non-stress test (NST)

Answer

Observation

Answer

Contraction stress test (CST)

Answer

Biophysical profile score (BPS)

Question 8

All the following are true regarding HIV transmission from mother to infant, EXCEPT:

Accepted Answer

Emergency Cesarean section increases the chance of transmission.

Answer

Nevirapine prophylaxis is used for the prevention of vertical transmission.

Answer

Zidovudine should be given to both pregnant women and infants.

Answer

Avoid breastfeeding.

Question 9

A primigravida presents with vaginal bleeding at term, but her vital signs are normal. What is the most appropriate management?

Accepted Answer

Examination under anesthesia with amniotomy

Answer

Immediate low-cesarean section

Answer

Conservative management

Answer

Classical cesarean section

Question 10

Which of the following strategies for administering magnesium sulfate for eclampsia prophylaxis should be used in the setting of an elevated serum creatinine?

Accepted Answer

None of the above

Answer

Give 3g loading dose followed by 2g/hr infusion

Answer

Give 3g loading dose, check magnesium level, and then titrate infusion rate

Answer

Give no loading dose and start infusion at 2g/hr

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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