Maternal-Fetal Medicine Practice Questions

Q: Which of the following conditions carries the highest relative risk for placental abruption?

Prior abruption. **Explanation:** Placental abruption (abruptio placentae) is the premature separation of a normally situated placenta. While its etiology is often multifactorial, the most significant risk factor is a history of the condition in a previous pregnancy. **1. Why "Prior Abruption" is Correct:** A history of prior abruption carries the **highest relative risk (RR)**, ranging from **10 to 15 times** higher than the general population. If a woman has had two prior abruptions, the risk of recurrence jumps to approximately 20-25%. This is due to underlying chronic vascular or genetic predispositions that persist across pregnancies. **2. Analysis of Incorrect Options:** * **Chorioamnionitis:** While intra-amniotic infection can lead to inflammation and trigger abruption, its relative risk is significantly lower than a prior history. * **Thrombophilia:** Inherited or acquired thrombophilias (like Factor V Leiden or APS) are associated with placental infarcts and abruption, but they are considered modest risk factors compared to the recurrence risk. * **Preterm Premature Rupture of Membranes (PPROM):** PPROM increases the risk of abruption (RR ~3-9) due to sudden uterine decompression or associated inflammation, but it remains secondary to the risk posed by a prior event. **Clinical Pearls for NEET-PG:** * **Most common risk factor:** Hypertension (Chronic or Gestational/Pre-eclampsia). * **Highest relative risk:** Prior placental abruption. * **Modifiable risk factors:** Smoking (doubles the risk) and Cocaine use (causes acute vasospasm). * **Classic Triad:** Painful vaginal bleeding, uterine tenderness (rigidity), and fetal distress. * **Couvelaire Uterus:** A complication where retroplacental blood infiltrates the myometrium, seen during C-section as a bluish/purplish discoloration.

Q: Which ultrasound finding has the highest association with aneuploidy?

Cystic hygroma. **Explanation:** **Cystic hygroma** is the correct answer because it has the strongest association with chromosomal abnormalities (aneuploidy) among the listed options. It is a congenital malformation of the lymphatic system, typically presenting as a fluid-filled sac in the posterior neck. Approximately **50-60%** of fetuses diagnosed with cystic hygroma in the first trimester have an underlying aneuploidy, most commonly **Turner syndrome (45,X)**, followed by Trisomy 21, 18, and 13. **Analysis of Incorrect Options:** * **Nuchal Translucency (NT):** While an increased NT is a major screening marker for Trisomy 21, it is often transient and can be seen in normal fetuses. Its association with aneuploidy is significant but statistically lower than that of a true cystic hygroma. * **Choroid Plexus Cyst (CPC):** These are considered "soft markers." While they are associated with Trisomy 18, the vast majority (over 95%) of CPCs occur in chromosomally normal fetuses and usually resolve by 26 weeks. * **Single Umbilical Artery (SUA):** This is the most common umbilical cord anomaly. While it increases the risk for renal and cardiac anomalies, its isolated presence has a very low correlation with aneuploidy. **Clinical Pearls for NEET-PG:** * **Turner Syndrome** is the most common association with cystic hygroma in the second trimester. * If a cystic hygroma is detected, the next best step is **karyotyping** (via CVS or Amniocentesis). * **Hydrops fetalis** often develops as a complication of cystic hygroma, leading to a poor prognosis.

Q: All of the following factors are used to assess intrauterine growth retardation, EXCEPT?

Fetal movements. **Explanation:** The diagnosis and assessment of **Intrauterine Growth Restriction (IUGR)** rely on objective measurements of fetal size and growth velocity. **Why Fetal Movements is the Correct Answer:** Fetal movements (Kick counts) are a subjective measure of **fetal well-being** and placental function, rather than a parameter for assessing growth. While a decrease in movements may indicate fetal distress in a growth-restricted fetus, it does not help in diagnosing or quantifying the degree of growth retardation itself. **Analysis of Incorrect Options:** * **Fundal Height:** This is the primary **clinical screening tool**. A symphysis-fundal height (SFH) lag of more than 3 cm compared to the gestational age suggests IUGR. * **Abdominal Circumference (AC):** This is the **most sensitive** sonographic parameter for diagnosing IUGR. Since the liver is the first organ to be affected by malnutrition (depletion of glycogen stores), the AC reduces significantly. * **Head Size (Biparietal Diameter/Head Circumference):** These are used to differentiate between **Symmetrical** (small head) and **Asymmetrical** (head-sparing) IUGR. The HC/AC ratio is a classic marker used in this assessment. **High-Yield Clinical Pearls for NEET-PG:** * **Best parameter for IUGR:** Abdominal Circumference (AC). * **Best parameter for Gestational Age:** Crown-Rump Length (CRL) in the 1st trimester. * **Ponderal Index:** Used to identify malnourished fetuses (Asymmetrical IUGR). * **Gold Standard for Monitoring:** Doppler Velocimetry (specifically the Umbilical Artery) is the best tool to manage IUGR and decide the timing of delivery.

Q: What is the investigation of choice for recurrent abortion in the first trimester?

Karyotyping. **Explanation:** Recurrent pregnancy loss (RPL) is defined as two or more consecutive spontaneous abortions. In the **first trimester**, the most common cause of sporadic miscarriage is chromosomal abnormalities. When these losses become recurrent, parental chromosomal anomalies (most commonly **balanced reciprocal translocations**) are a significant underlying factor. **1. Why Karyotyping is the Investigation of Choice:** Parental **Karyotyping** is the gold standard investigation to identify structural chromosomal rearrangements. If one parent carries a balanced translocation, they are phenotypically normal but produce unbalanced gametes, leading to recurrent embryonic aneuploidy and subsequent first-trimester loss. **2. Analysis of Incorrect Options:** * **SLE antibodies (Antiphospholipid Antibodies):** While Antiphospholipid Syndrome (APLAs) is a major cause of RPL, it is more classically associated with second-trimester losses or specific late-term complications (though it can cause early loss). Karyotyping remains the primary genetic screen for early-first-trimester recurrence. * **HIV testing:** HIV is not a recognized cause of recurrent pregnancy loss. * **TORCH infection screening:** This is a common misconception. TORCH infections (Toxoplasmosis, Rubella, CMV, Herpes) cause **sporadic** fetal loss or malformations, but they do **not** cause recurrent abortions because the mother develops immunity after the initial infection. **Clinical Pearls for NEET-PG:** * **Most common cause of 1st-trimester abortion:** Fetal chromosomal anomaly (Autosomal trisomy is the most common; specifically Trisomy 16). * **Most common parental anomaly in RPL:** Balanced reciprocal translocation. * **Uterine causes:** Septate uterus is the most common uterine anomaly associated with RPL. * **Investigation Timing:** Karyotyping should be performed on both parents and, if possible, the products of conception (POC).

Q: Which of the following maternal factors is most commonly associated with first-trimester pregnancy loss?

Advanced maternal age. **Explanation:** **1. Why Advanced Maternal Age (AMA) is the correct answer:** Advanced maternal age (typically defined as ≥35 years) is the most significant maternal risk factor for first-trimester pregnancy loss. The underlying medical concept is the **decline in oocyte quality and quantity**. As maternal age increases, there is a higher incidence of **meiotic non-disjunction**, leading to fetal chromosomal abnormalities (aneuploidies). Since approximately 50–70% of all first-trimester miscarriages are caused by chromosomal anomalies (most commonly autosomal trisomies), AMA directly correlates with the highest risk of loss. **2. Why the other options are incorrect:** * **Incompetent Cervix:** This is a classic cause of **second-trimester** (mid-trimester) pregnancy loss, characterized by painless cervical dilatation and membrane prolapse, rather than first-trimester loss. * **Intrauterine Infection:** While infections (like TORCH or bacterial vaginosis) can cause sporadic loss, they are much less common than chromosomal causes in the first trimester. * **Hyperemesis Gravidarum:** This condition involves severe nausea and vomiting. While it can lead to maternal dehydration and electrolyte imbalance, it is generally associated with *favorable* pregnancy outcomes and is not a cause of miscarriage. **3. NEET-PG High-Yield Pearls:** * **Most common cause of 1st-trimester miscarriage:** Fetal chromosomal anomalies (Aneuploidy). * **Most common specific chromosomal anomaly:** Autosomal Trisomy (Trisomy 16 is the most common specific trisomy found in abortuses). * **Most common single chromosomal anomaly:** Monosomy X (Turner Syndrome, 45,X). * **Risk of miscarriage:** At age 20-24, the risk is ~10%; by age 45, the risk exceeds 50-75%.

Q: A 32-year-old primigravida, at 35 weeks gestation, is admitted to the antenatal ward. Her blood pressure is found to be 160/110 mmHg, and her urine does not contain albumin. Which of the following drugs should not be used in her management?

Furosemide. ### Explanation **Correct Option: A (Furosemide)** The patient presents with **Severe Gestational Hypertension** (BP ≥160/110 mmHg without proteinuria). In hypertensive disorders of pregnancy (HDP), there is a paradoxical state of **pathological plasma volume contraction** despite systemic edema. **Furosemide (a loop diuretic)** is generally contraindicated because it further depletes intravascular volume, leading to decreased placental perfusion and potential fetal compromise. Diuretics are strictly reserved for specific complications like **acute pulmonary edema** or congestive heart failure in pregnancy. **Analysis of Incorrect Options:** * **B. Hydralazine:** A potent vasodilator used frequently in the acute management of severe hypertension in pregnancy (hypertensive crisis). It is a safe and effective second-line agent. * **C. Labetalol:** A combined alpha and beta-blocker. It is considered the **first-line intravenous drug** for the acute management of severe hypertension in pregnancy due to its rapid onset and favorable safety profile. * **D. Methyldopa:** A centrally acting alpha-2 agonist. It is the **drug of choice for chronic hypertension** in pregnancy due to its long-term safety record, though it is less effective for acute hypertensive emergencies due to its slow onset of action. **NEET-PG High-Yield Pearls:** * **Drug of Choice (DOC) for Chronic Hypertension in Pregnancy:** Methyldopa. * **DOC for Acute Hypertensive Crisis in Pregnancy:** IV Labetalol (Hydralazine is an alternative). * **DOC for Eclampsia Prophylaxis/Treatment:** Magnesium Sulfate ($MgSO_4$). * **ACE Inhibitors/ARBs:** Strictly contraindicated in pregnancy (cause fetal renal dysgenesis and skull defects). * **Target BP in Pregnancy:** Aim to maintain Systolic 140–150 mmHg and Diastolic 90–100 mmHg to prevent maternal cerebrovascular accidents without compromising placental blood flow.

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).

Question 1

Which of the following conditions carries the highest relative risk for placental abruption?

Accepted Answer

Prior abruption

Answer

Chorioamnionitis

Answer

Thrombophilia

Answer

Preterm rupture of membranes

Question 2

Which ultrasound finding has the highest association with aneuploidy?

Accepted Answer

Cystic hygroma

Answer

Choroid plexus cyst

Answer

Nuchal translucency

Answer

Single umbilical artery

Question 3

All of the following factors are used to assess intrauterine growth retardation, EXCEPT?

Accepted Answer

Fetal movements

Answer

Head size

Answer

Fundal height

Answer

Abdominal circumference

Question 4

What is the investigation of choice for recurrent abortion in the first trimester?

Accepted Answer

Karyotyping

Answer

Systemic Lupus Erythematosus (SLE) antibodies

Answer

Human Immunodeficiency Virus (HIV) testing

Answer

TORCH infection screening

Question 5

Which of the following maternal factors is most commonly associated with first-trimester pregnancy loss?

Accepted Answer

Advanced maternal age

Answer

Incompetent cervix

Answer

Intrauterine infection

Answer

Hyperemesis gravidarum

Question 6

A 32-year-old primigravida, at 35 weeks gestation, is admitted to the antenatal ward. Her blood pressure is found to be 160/110 mmHg, and her urine does not contain albumin. Which of the following drugs should not be used in her management?

Accepted Answer

Furosemide

Answer

Hydralazine

Answer

Labetalol

Answer

Methyldopa

Question 7

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 8

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 9

What is the cause of convulsions in eclampsia?

Accepted Answer

Cerebral anoxia due to aerial spasm

Answer

Hypovolemia

Answer

Hypocalcemia

Answer

Shock

Question 10

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

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

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