Maternal-Fetal Medicine Practice Questions

Q: What is the preventive dose of anti-D gamma globulin given to a mother?

300 mcg. **Explanation:** The standard preventive dose of Anti-D gamma globulin (RhoGAM) for a non-sensitized Rh-negative mother is **300 mcg** (equivalent to 1500 IU). This dose is administered intramuscularly to prevent Rh isoimmunization by neutralizing fetal Rh-positive red blood cells that may enter the maternal circulation. **Why 300 mcg is correct:** A 300 mcg dose is specifically designed to neutralize up to **30 mL of fetal whole blood** (or 15 mL of fetal packed red cells). This volume is sufficient to cover the majority of feto-maternal hemorrhages (FMH) occurring during a standard delivery or third-trimester events. **Analysis of Incorrect Options:** * **A. 200 mcg:** This is an insufficient dose for standard third-trimester prophylaxis or delivery. However, a lower dose of **50 mcg** is often used for first-trimester events (e.g., abortion before 12 weeks), as the fetal blood volume is much smaller. * **C & D. 400 mcg / 500 mcg:** These doses exceed the standard prophylactic requirement. While higher doses are administered if a Kleihauer-Betke (KB) test confirms a massive FMH (>30 mL), they are not the "standard" preventive dose. **High-Yield Clinical Pearls for NEET-PG:** * **Timing:** Routine antenatal prophylaxis is given at **28 weeks** gestation. Postpartum, it must be given within **72 hours** of delivery if the neonate is Rh-positive. * **Kleihauer-Betke Test:** Used to quantify the volume of FMH to determine if additional doses of Anti-D are required. * **Route:** Intramuscular (IM) is standard. * **Indirect Coombs Test (ICT):** Must be negative in the mother before administration (indicating she is not yet sensitized).

Q: What is the cause of convulsions in eclampsia?

Cerebral anoxia due to aerial spasm. ### Explanation The pathophysiology of eclampsia is centered on severe vascular dysfunction. The correct answer is **Cerebral anoxia due to arterial spasm**. **1. Why Option A is Correct:** In eclampsia, severe hypertension and endothelial dysfunction lead to intense **vasospasm** of the cerebral arterioles. This "arterial spasm" results in increased vascular resistance and reduced cerebral blood flow. The subsequent **cerebral anoxia** (lack of oxygen) and localized edema trigger neuronal hyperexcitability, manifesting as generalized tonic-clonic seizures. Additionally, the breakdown of the blood-brain barrier (vasogenic edema) contributes to the neurological symptoms. **2. Why the Other Options are Incorrect:** * **Hypovolemia (B):** While pre-eclampsia involves a contracted intravascular volume due to "capillary leak," hypovolemia itself causes tachycardia and hypotension (shock), not convulsions. * **Hypocalcemia (C):** Although hypocalcemia can cause tetany and seizures, it is not the primary mechanism of eclampsia. However, Magnesium Sulfate (the treatment for eclampsia) can occasionally cause functional hypocalcemia. * **Shock (D):** Shock represents circulatory collapse. In eclampsia, the patient is typically hypertensive, not hypotensive, unless a complication like abruptio placentae or postpartum hemorrhage occurs. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice:** Magnesium Sulfate ($MgSO_4$) is the gold standard for both prophylaxis and control of seizures (Pritchard Regimen). * **Definitive Treatment:** Delivery of the fetus and placenta is the only definitive cure for eclampsia. * **Most Common Timing:** Most convulsions occur **antepartum** (50%), followed by intrapartum (25%) and postpartum (25%). * **Warning Signs:** "Imminent eclampsia" is characterized by headache, epigastric pain, and visual disturbances (scotomata).

Q: What is the most important cause of coagulation failure in obstetrics?

Accidental hemorrhage. **Explanation:** **Accidental hemorrhage (Abruptio Placentae)** is the most common and important cause of Disseminated Intravascular Coagulation (DIC) in obstetrics. The underlying mechanism involves the release of a massive amount of **tissue thromboplastin** from the damaged placenta and retroplacental clot into the maternal circulation. This triggers the extrinsic coagulation pathway, leading to widespread consumption of clotting factors (fibrinogen, platelets, Factors V and VIII), ultimately resulting in coagulation failure. **Analysis of Options:** * **Intrauterine Fetal Death (IUFD):** While IUFD can cause DIC, it typically takes **3–4 weeks** of the dead fetus being retained in utero for thromboplastin to leak sufficiently into the maternal system. It is a slower process compared to the acute onset seen in Abruption. * **Placenta Previa:** This condition involves painless bleeding without significant retroplacental clot formation or tissue damage. Therefore, the release of thromboplastin is negligible, and DIC is extremely rare. * **Rupture of the Uterus:** While this causes massive obstetric hemorrhage and shock, it does not inherently trigger the systemic consumptive coagulopathy pathway as directly or frequently as Abruptio Placentae does. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of DIC in pregnancy:** Abruptio Placentae. * **Most common cause of Septic Shock in obstetrics:** Septic Abortion. * **Couvelaire Uterus:** Seen in severe Abruptio Placentae where blood infiltrates the myometrium; it is a risk factor for postpartum hemorrhage (PPH) but not an absolute indication for hysterectomy. * **Bedside Test:** The **"Modified Weiner’s Clot Observation Test"** is a quick bedside tool to screen for coagulation failure (failure of a 5ml blood sample to clot within 6–10 minutes or a clot that dissolves quickly).

Q: Which of the following methods does not improve fetoplacental function in women with IUGR?

Allyl estranol. **Explanation:** Intrauterine Growth Restriction (IUGR) is primarily managed by improving uteroplacental blood flow and optimizing maternal nutrition. **Why Allyl estranol is the correct answer:** Allyl estranol is a synthetic progestogen. While it was historically used to prevent miscarriage or preterm labor, large-scale clinical trials and Cochrane reviews have proven that it has **no role** in improving fetoplacental function or treating IUGR. It does not increase placental perfusion or fetal weight. In modern obstetrics, its use for growth restriction is considered obsolete and ineffective. **Why the other options are incorrect:** * **High protein diet:** Maternal malnutrition is a modifiable risk factor. Supplementing the mother with a balanced, high-protein diet ensures adequate amino acid transfer to the fetus, which is essential for cellular growth and improving fetal weight. * **Left lateral position:** This is a fundamental nursing intervention. It prevents **aortocaval compression** by the gravid uterus, thereby increasing venous return to the heart, improving cardiac output, and maximizing uterine artery blood flow to the placenta. * **Intermittent O2 therapy:** Administering oxygen to the mother increases the oxygen concentration gradient across the placenta. This can temporarily improve fetal oxygenation and is sometimes used in cases of suspected fetal distress or severe growth restriction. **Clinical Pearls for NEET-PG:** * **Bed Rest:** The most effective non-pharmacological "treatment" for IUGR is bed rest in the left lateral position. * **Low-dose Aspirin (75-150 mg):** If started before 16 weeks, it can help prevent IUGR in high-risk women by improving trophoblastic invasion. * **Definitive Management:** The only definitive "cure" for IUGR is delivery once the fetus has reached a viable age or if fetal surveillance (Doppler/NST) indicates compromise.

Q: All of the following are complications in a pregnant woman with systemic lupus erythematosus (SLE) disease except?

Post-term delivery. **Explanation:** Systemic Lupus Erythematosus (SLE) is a multisystem autoimmune disorder that significantly impacts pregnancy outcomes. The core pathophysiology involves immune complex deposition and vasculitis, which compromises placental function. **Why Post-term delivery is the correct answer:** In SLE, the primary concern is **placental insufficiency** caused by decidual vasculopathy. This leads to complications that necessitate early delivery, either due to spontaneous onset (preterm labor) or medical induction (fetal distress/preeclampsia). Therefore, SLE is associated with **preterm delivery**, not post-term delivery. **Analysis of Incorrect Options:** * **Preterm Labor:** This is a hallmark complication of SLE, occurring in up to 30-50% of cases due to premature rupture of membranes, placental abruption, or iatrogenic delivery for maternal/fetal indications. * **Thrombophilia:** SLE is frequently associated with **Antiphospholipid Syndrome (APS)**. The presence of Lupus Anticoagulant or Anticardiolipin antibodies creates a hypercoagulable state, leading to venous/arterial thrombosis and placental infarctions. * **Eclampsia:** SLE patients have a significantly higher risk of **Preeclampsia and Eclampsia**. Differentiating between a "Lupus Nephritis flare" and "Preeclampsia" is a common clinical challenge; however, both conditions predispose the patient to hypertensive crises and seizures. **High-Yield Clinical Pearls for NEET-PG:** * **Best time to conceive:** When SLE has been in remission for at least **6 months**. * **Neonatal Lupus:** Caused by transplacental passage of **Anti-Ro (SS-A)** and **Anti-La (SS-B)** antibodies. The most serious permanent complication is **Congenital Heart Block**. * **Drug of Choice:** **Hydroxychloroquine** is safe and should be continued throughout pregnancy to prevent flares. * **Flare Marker:** Low complement levels (**C3, C4**) usually indicate an SLE flare rather than preeclampsia.

Q: In a primigravida patient experiencing preterm labor, which of the following can be used as a tocolytic agent?

Ritodrine and MgSO4. **Explanation:** **1. Why Option B is Correct:** Tocolytics are drugs used to suppress uterine contractions to delay delivery, typically for 48 hours, allowing for corticosteroid administration or maternal transport. * **Ritodrine** is a **Beta-2 adrenergic agonist** that increases intracellular cAMP, leading to smooth muscle relaxation (uterine quiescence). * **Magnesium Sulfate (MgSO4)** acts as a calcium antagonist, competing with calcium at the motor endplate and inhibiting myometrial contractility. In preterm labor, MgSO4 serves a dual purpose: tocolysis and **fetal neuroprotection** (reducing the risk of cerebral palsy). **2. Analysis of Incorrect Options:** * **Option A & D:** **Dexamethasone** is a corticosteroid used for fetal lung maturity (to prevent RDS, IVH, and NEC). While it is essential in preterm labor management, it is **not a tocolytic agent** as it has no effect on uterine contractions. * **Option C:** **Propranolol** is a non-selective **Beta-blocker**. Since Beta-2 stimulation causes uterine relaxation, a Beta-blocker would theoretically increase uterine activity and is contraindicated when tocolysis is desired. **3. High-Yield Clinical Pearls for NEET-PG:** * **First-line Tocolytic:** Currently, **Nifedipine** (Calcium Channel Blocker) is the preferred first-line agent due to its oral efficacy and better safety profile compared to Ritodrine. * **Atosiban:** A competitive Oxytocin receptor antagonist; highly specific with fewer side effects but expensive. * **Indomethacin:** A COX inhibitor used as a tocolytic, but contraindicated after **32 weeks** due to the risk of premature closure of the *ductus arteriosus* and oligohydramnios. * **Ritodrine Side Effects:** Maternal tachycardia, pulmonary edema, and hyperglycemia.

Q: What is the most common presentation in twin pregnancies?

Both Vertex. **Explanation:** In twin pregnancies, the presentation of the fetuses is determined by the available intrauterine space and the tendency of the fetuses to accommodate the oval shape of the uterus. **1. Why "Both Vertex" is correct:** Cephalic (Vertex) presentation is the most common presentation for a single fetus (95%), and this trend continues in multifetal gestations. **Vertex-Vertex** is the most frequent combination, occurring in approximately **40–50%** of all twin pregnancies. This is the most favorable presentation for a planned vaginal delivery, provided there are no other contraindications. **2. Analysis of Incorrect Options:** * **Vertex + Breech (Option C):** This is the second most common presentation, occurring in about **30–35%** of cases. While common, it is statistically less frequent than both being vertex. * **Vertex + Transverse (Option A):** This occurs in approximately **10%** of cases. It is less common because the transverse lie is unstable and usually converts to longitudinal as the pregnancy progresses. * **Both Breech (Option D):** This is relatively rare, occurring in only about **10%** of twin pregnancies. **3. High-Yield Clinical Pearls for NEET-PG:** * **Management Rule:** If the first twin (Twin A) is non-vertex, a Cesarean Section is generally indicated regardless of the presentation of Twin B. * **Internal Podalic Version:** This is a classic obstetric maneuver that may be used for the delivery of a **second twin** (Twin B) if it is in a non-vertex presentation (like transverse) after the successful vaginal birth of Twin A. * **Locked Twins:** A rare but serious complication (1 in 1000 twin births) most commonly seen when **Twin A is Breech and Twin B is Vertex**. Their chins become interlocked, necessitating a C-section.

Question 1

What is the treatment of choice for an unruptured tubal pregnancy with a serum p-hCG titre of 2000 IU/mL?

Accepted Answer

Single dose of methotrexate

Answer

Variable dose of methotrexate

Answer

Expectant management

Answer

Laparoscopic salpingostomy

Question 2

What is the preventive dose of anti-D gamma globulin given to a mother?

Accepted Answer

300 mcg

Answer

200 mcg

Answer

400 mcg

Answer

500 mcg

Question 3

What is the cause of convulsions in eclampsia?

Accepted Answer

Cerebral anoxia due to aerial spasm

Answer

Hypovolemia

Answer

Hypocalcemia

Answer

Shock

Question 4

What is the most important cause of coagulation failure in obstetrics?

Accepted Answer

Accidental hemorrhage

Answer

Intrauterine fetal death

Answer

Placenta previa

Answer

Rupture of the uterus

Question 5

Which of the following methods does not improve fetoplacental function in women with IUGR?

Accepted Answer

Allyl estranol

Answer

High protein diet

Answer

Left lateral position

Answer

Intermittent O2 therapy

Question 6

All of the following are complications in a pregnant woman with systemic lupus erythematosus (SLE) disease except?

Accepted Answer

Post-term delivery

Answer

Preterm labor

Answer

Thrombophilia

Answer

Eclampsia

Question 7

What advice should be given to an HIV-positive primigravida near term regarding labor and delivery?

Accepted Answer

Cesarean section would decrease transmission of HIV to the baby.

Answer

Treatment should be started before labor.

Answer

Avoid mixing of blood intrapartum.

Answer

Vaginal delivery is preferred.

Question 8

In a primigravida patient experiencing preterm labor, which of the following can be used as a tocolytic agent?

Accepted Answer

Ritodrine and MgSO4

Answer

Ritodrine and Dexamethasone

Answer

Ritodrine and Propranolol

Answer

MgSO4 and Dexamethasone

Question 9

What is the most common presentation in twin pregnancies?

Accepted Answer

Both Vertex

Answer

Vertex + Transverse

Answer

Vertex + Breech

Answer

Both Breech

Question 10

The Kleihaeur-Betke test is performed to detect:

Accepted Answer

Fetomaternal hemorrhage

Answer

Cephalopelvic disproportion

Answer

Karyotype of a normal fetus

Answer

Fetal infections

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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