Maternal-Fetal Medicine Practice Questions

Q: MgSO4 is contraindicated in eclampsia during treatment EXCEPT when which of the following occurs?

Respiratory rate is < 16/min. **Explanation:** Magnesium sulfate ($MgSO_4$) is the drug of choice for controlling and preventing seizures in eclampsia. However, it has a narrow therapeutic index and is excreted solely by the kidneys. Monitoring for magnesium toxicity is critical to prevent respiratory paralysis and cardiac arrest. **Why Option B is the Correct Answer:** The question asks when $MgSO_4$ is **NOT** contraindicated (i.e., when it can still be administered). According to standard protocols (Pritchard’s regimen), the clinical monitoring parameters for continuing $MgSO_4$ are: 1. **Respiratory Rate (RR) $\geq$ 12–14/min:** A rate of **16/min** is within the normal range and indicates no respiratory depression. Therefore, $MgSO_4$ is **not** contraindicated at this rate. 2. **Presence of Patellar Reflex (Knee Jerk):** Its disappearance is the first sign of toxicity. 3. **Urine Output $\geq$ 30 ml/hr:** To ensure adequate drug clearance. **Analysis of Incorrect Options:** * **Option A (Urine output < 30 ml/hr):** This indicates renal impairment. Since $MgSO_4$ is excreted by kidneys, continuing it would lead to toxic accumulation. * **Option D (Knee jerk is absent):** Loss of deep tendon reflexes (DTRs) occurs at plasma levels of 7–10 mEq/L and is the earliest warning sign of toxicity. Administration must be stopped. * **Option C (Diastolic BP < 90 mmHg):** While not a direct contraindication for $MgSO_4$ toxicity, it is irrelevant to the specific safety monitoring of Magnesium. $MgSO_4$ is an anticonvulsant, not primarily an antihypertensive. **High-Yield Clinical Pearls for NEET-PG:** * **Therapeutic range:** 4–7 mEq/L. * **Sequence of Toxicity:** Loss of Knee Jerk (7–10 mEq/L) $\rightarrow$ Respiratory Depression (11–15 mEq/L) $\rightarrow$ Cardiac Arrest (>15 mEq/L). * **Antidote:** 10 ml of 10% **Calcium Gluconate** IV (administered slowly over 10 minutes).

Q: A Rh negative G4P3+0 patient has an antibody level of 15 IU/ml (IAT 1:32) at 27 weeks gestation. What is the most appropriate next step in management?

Estimate middle cerebral artery peak systolic velocity. In Rh-isoimmunized pregnancies, the management goal is to detect fetal anemia before hydrops develops. **Explanation of the Correct Answer:** The patient is sensitized (Antibody titer ≥ 1:16 or > 4 IU/ml), which puts the fetus at risk for Hemolytic Disease of the Fetus and Newborn (HDFN). **Middle Cerebral Artery Peak Systolic Velocity (MCA-PSV)** is the current gold standard for non-invasive screening of fetal anemia. * **Mechanism:** In fetal anemia, blood viscosity decreases and cardiac output increases to maintain oxygen delivery. This results in a higher velocity of blood flow. * **Threshold:** An MCA-PSV **> 1.5 MoM** (Multiples of Median) indicates severe anemia and is the trigger for invasive intervention. **Why Other Options are Incorrect:** * **A. Amniotic fluid bilirubin (Liley’s Chart):** Historically used to measure ΔOD450, this is now largely obsolete because it is invasive and less accurate than MCA-PSV, especially in the second trimester. * **B. Cordocentesis:** This is an invasive procedure with a 1-2% risk of fetal loss. It is used for definitive diagnosis and to prepare for transfusion, but it is not the *initial* screening step. * **D. Intrauterine Transfusion (IUT):** This is a therapeutic intervention, not a diagnostic step. It is only performed if fetal hemoglobin is confirmed to be 2 SD below the mean for gestational age. **Clinical Pearls for NEET-PG:** * **Critical Titer:** 1:16 is generally considered the threshold for monitoring; below this, the risk of hydrops is negligible. * **Best Timing:** MCA-PSV is most accurate between 18 and 35 weeks of gestation. * **First Step in Sensitized Pregnancy:** Always determine the paternal Rh status and zygosity first. If the father is heterozygous, fetal RHD genotyping (via cffDNA) is the next step.

Q: A gravida 3 female with a history of 2 previous second-trimester abortions presents at 22 weeks of gestation with cervical funneling. What is the most appropriate management?

Apply McDonald suture. ### Explanation The clinical presentation of a patient with a history of recurrent second-trimester abortions and current cervical funneling (shortening and opening of the internal os) is diagnostic of **Cervical Insufficiency**. **1. Why Option D is Correct:** The management of cervical insufficiency is **Cervical Cerclage**. Since the patient is currently at 22 weeks and demonstrating ultrasound changes (funneling), this is classified as **Ultrasound-Indicated Cerclage** (also known as "Rescue" or "Emergency" cerclage if the cervix is dilated). The **McDonald suture** is the most commonly performed technique; it involves a non-absorbable purse-string suture placed at the cervicovaginal junction to provide mechanical support to the weak cervix, thereby preventing premature delivery. **2. Why Other Options are Incorrect:** * **Options A & B (Dinoprostone/Misoprostol):** These are prostaglandins used for cervical ripening and induction of labor or abortion. Administering them in this scenario would be contraindicated as they would further soften the cervix and lead to pregnancy loss. * **Option C (Fothergill Suture):** This is a component of the Manchester operation used for treating **pelvic organ prolapse** (uterine descent) in women who wish to retain their uterus. It is not used for cervical insufficiency in pregnancy. **3. NEET-PG High-Yield Pearls:** * **Timing:** Prophylactic (History-indicated) cerclage is typically performed at **12–14 weeks**. * **Diagnosis:** On Ultrasound, a cervical length **<25 mm** or significant **funneling** (T, Y, V, U shapes) before 24 weeks indicates insufficiency. * **Suture Material:** Usually Mersilene tape (non-absorbable). * **Removal:** The suture is electively removed at **36–37 weeks** or immediately if labor starts to prevent cervical laceration. * **Contraindications:** Chorioamnionitis, active bleeding, ruptured membranes, or fetal anomalies.

Q: What is the most reliable method for diagnosing fetal wellbeing?

Ultrasound. **Explanation:** The assessment of fetal wellbeing has evolved from biochemical markers to real-time biophysical evaluation. **Ultrasound** is currently the most reliable method because it allows for a comprehensive, non-invasive, and immediate assessment of the fetus. It forms the basis of the **Biophysical Profile (BPP)** and **Doppler velocimetry**, which evaluate acute markers (fetal breathing, movements, tone, and heart rate) and chronic markers (amniotic fluid index and placental perfusion). **Analysis of Options:** * **A. L:S Ratio (Lecithin-Sphingomyelin):** This is a marker of **fetal lung maturity**, not overall wellbeing. While it predicts the risk of Respiratory Distress Syndrome (RDS), it does not provide information regarding acute fetal distress or placental function. * **B. HPL (Human Placental Lactogen) levels:** Formerly used as a "placental function test," HPL levels are no longer considered reliable. They have a wide range of normal values and poor sensitivity in predicting acute fetal compromise. * **C. Kick Test (Daily Fetal Movement Count):** While a valuable screening tool for mothers to monitor at home, it is **subjective** and can be influenced by maternal perception, obesity, or fetal sleep cycles. It is less reliable than objective ultrasound findings. **High-Yield Clinical Pearls for NEET-PG:** * **Modified BPP:** Combines the Non-Stress Test (NST) (acute indicator) and Amniotic Fluid Index (AFI) (chronic indicator). * **Umbilical Artery Doppler:** The most sensitive tool for monitoring growth-restricted (IUGR) fetuses; "Absent or Reversed End-Diastolic Flow" is a critical sign of impending compromise. * **First sign to disappear in fetal distress:** Fetal breathing movements. * **Last sign to disappear:** Fetal tone (indicates severe acidemia).

Q: Early diastolic notching of the uterine artery disappears by which week of gestation?

22 weeks. **Explanation:** The correct answer is **22 weeks**. **Underlying Medical Concept:** In a non-pregnant state, the uterine artery is a high-resistance vessel characterized by an **early diastolic notch**. During a normal pregnancy, trophoblastic invasion of the spiral arteries occurs in two waves (at 8–10 weeks and 16–18 weeks). This process converts the uterine circulation from a high-resistance to a low-resistance, high-flow system to ensure adequate placental perfusion. As resistance falls, the diastolic flow increases, and the early diastolic notch typically disappears by **22–24 weeks** of gestation. Persistence of this notch beyond 24 weeks is a significant predictor of placental insufficiency. **Analysis of Options:** * **A & B (20 & 21 weeks):** While the transition begins earlier, the physiological remodeling is often incomplete at this stage. Using these weeks as a cutoff would result in a high false-positive rate for predicting complications. * **C (22 weeks):** This is the standard clinical benchmark. By the end of the 22nd week, the notch should ideally disappear in a healthy pregnancy. * **D (24 weeks):** While some sources mention 24 weeks as the absolute upper limit, **22 weeks** is the most frequently tested "milestone" week for the disappearance of the notch in competitive exams like NEET-PG. **High-Yield Clinical Pearls for NEET-PG:** * **Persistence of the notch:** If the notch persists beyond 24 weeks, it indicates a high risk for **Preeclampsia** and **Intrauterine Growth Restriction (IUGR)**. * **Best time for screening:** Uterine artery Doppler screening for preeclampsia is ideally performed between **11–14 weeks** (PI) and **20–24 weeks** (Notching). * **Reversed End-Diastolic Flow (REDF):** In the umbilical artery, this is a critical sign of fetal distress and often an indication for urgent delivery.

Q: What does the following ultrasound show?

Ectopic pregnancy. ***Ectopic pregnancy*** - Classic **transvaginal ultrasound** findings include the **adnexal ring sign** (hyperechoic ring in the fallopian tube) and an **empty uterine cavity** despite positive pregnancy test. - Often shows **free fluid** in the **pouch of Douglas** indicating potential tubal rupture or bleeding. *Normal pregnancy* - Shows a **gestational sac** within the **uterine cavity** with appropriate size for gestational age. - **Fetal pole** and **cardiac activity** are visible in viable intrauterine pregnancies after 6-7 weeks. *Hydatidiform mole* - Characteristic **"snowstorm appearance"** with multiple **cystic spaces** and **echogenic material** filling the uterine cavity. - Absence of **normal fetal structures** and markedly elevated **β-hCG levels** compared to gestational age. *Ovarian cyst* - Appears as a **simple fluid-filled structure** with **thin walls** and **anechoic contents** in the ovary. - **Uterine cavity** would show normal intrauterine pregnancy if patient is pregnant, not the empty uterus seen in ectopic pregnancy.

Q: What is the drug of choice for the prevention of seizures in a patient with severe preeclampsia?

Magnesium sulphate. **Explanation:** **Magnesium sulphate ($MgSO_4$)** is the gold standard and drug of choice for both the **prevention (prophylaxis)** of seizures in severe preeclampsia and the **control** of seizures in eclampsia. Its superiority over other anticonvulsants was definitively established by the **MAGPIE trial**. It acts primarily by blocking NMDA receptors in the brain, increasing the seizure threshold, and causing cerebral vasodilation to reduce ischemia. **Analysis of Incorrect Options:** * **A. Phenytoin:** While an effective antiepileptic, it is less effective than $MgSO_4$ in preventing eclamptic seizures and carries a higher risk of maternal toxicity and fetal side effects. * **C. Diazepam:** Formerly used for seizure control, it is now avoided as a first-line agent because it causes significant maternal respiratory depression and neonatal "Floppy Infant Syndrome." * **D. Nifedipine:** This is a Calcium Channel Blocker used as an **antihypertensive** to manage blood pressure in preeclampsia, but it has no anticonvulsant properties. **High-Yield Clinical Pearls for NEET-PG:** * **Regimen:** The **Pritchard Regimen** (IM) and **Zuspan Regimen** (IV) are the standard protocols. * **Therapeutic Window:** 4–7 mEq/L. * **Monitoring:** Always check for **Patellar reflex** (first sign of toxicity is loss of reflex), **Respiratory rate** (>12/min), and **Urine output** (>30 ml/hr) before each dose. * **Antidote:** **Calcium gluconate** (10 ml of 10% solution administered IV over 10 minutes). * **Excretion:** It is exclusively cleared by the kidneys; hence, dose adjustment is mandatory in renal failure.

Question 1

MgSO4 is contraindicated in eclampsia during treatment EXCEPT when which of the following occurs?

Accepted Answer

Respiratory rate is < 16/min

Answer

Urine output is < 30 ml/hr

Answer

Diastolic blood pressure is < 90 mmHg

Answer

Knee jerk is absent

Question 2

A Rh negative G4P3+0 patient has an antibody level of 15 IU/ml (IAT 1:32) at 27 weeks gestation. What is the most appropriate next step in management?

Accepted Answer

Estimate middle cerebral artery peak systolic velocity

Answer

Estimate amniotic fluid bilirubin levels

Answer

Estimate fetal hemoglobin levels by cordocentesis

Answer

Perform intrauterine transfusion

Question 3

A 24-year-old woman at 8 weeks of gestation presents with a history of pulmonary embolism 7 years ago during her first pregnancy. She was treated with intravenous heparin followed by several months of oral warfarin and has had no further evidence of thromboembolic disease for over 6 years. Which of the following statements about her current condition is true?

Accepted Answer

The patient should be placed on low-dose heparin therapy throughout pregnancy and puerperium.

Answer

Having no evidence of disease for over 5 years means that the risk of thromboembolism is not greater than normal.

Answer

Impedance plethysmography is not a useful study to evaluate for deep venous thrombosis in pregnancy.

Answer

Doppler ultrasonography is not a useful technique to evaluate for deep venous thrombosis in pregnancy.

Question 4

A gravida 3 female with a history of 2 previous second-trimester abortions presents at 22 weeks of gestation with cervical funneling. What is the most appropriate management?

Accepted Answer

Apply McDonald suture

Answer

Administer dinoprostone and bed rest

Answer

Administer misoprostol and bed rest

Answer

Apply Fothergill suture

Question 5

Which of the following situations poses the greatest risk of Rh incompatibility?

Accepted Answer

Rh-ve mother with a second Rh+ve child

Answer

Rh+ve mother with a second Rh-ve child

Answer

Rh+ve mother with a first Rh-ve child

Answer

Rh-ve mother with a first Rh+ve child

Question 6

What is the most reliable method for diagnosing fetal wellbeing?

Accepted Answer

Ultrasound

Answer

L:S ratio

Answer

HPL levels

Answer

Kick test

Question 7

Early diastolic notching of the uterine artery disappears by which week of gestation?

Accepted Answer

22 weeks

Answer

20 weeks

Answer

21 weeks

Answer

24 weeks

Question 8

A 22-year-old woman presents with sudden onset of severe lower abdominal pain. Physical examination reveals no masses but severe tenderness in the right lower quadrant. Pelvic examination shows no lesions of the cervix or vagina. Bowel sounds are present. An abdominal ultrasound scan shows a 4-cm focal enlargement of the proximal right fallopian tube. A dilation and curettage procedure reveals decidua only from the endometrial cavity. Which of the following laboratory findings is most likely to be reported for this patient?

Accepted Answer

Detection of human chorionic gonadotropin in serum

Answer

Cervical culture positive for Neisseria gonorrhoeae

Answer

69, XXY karyotype on decidual tissue cells

Answer

Pap smear showing pseudo hyphae of Candida

Question 9

What does the following ultrasound show?

Accepted Answer

Ectopic pregnancy

Answer

Normal pregnancy

Answer

Hydatidiform mole

Answer

Ovarian cyst

Question 10

What is the drug of choice for the prevention of seizures in a patient with severe preeclampsia?

Accepted Answer

Magnesium sulphate

Answer

Phenytoin

Answer

Diazepam

Answer

Nifedipine

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

On this page

Practice by Chapter

Want unlimited practice?