Maternal-Fetal Medicine Practice Questions

Q: What is the earliest sign of magnesium toxicity?

Falling oxygen saturation on pulse oximetry. **Explanation:** Magnesium sulfate ($MgSO_4$) is the drug of choice for seizure prophylaxis in pre-eclampsia and control in eclampsia. However, it has a narrow therapeutic index (4–7 mEq/L). **Why Option A is Correct:** Traditionally, the loss of deep tendon reflexes (patellar reflex) was taught as the first clinical sign of toxicity. However, recent clinical evidence and updated protocols highlight that **falling oxygen saturation ($SpO_2 < 95\%$)** on pulse oximetry is the **earliest objective indicator** of magnesium toxicity. This occurs due to the weakening of respiratory muscles and minor changes in alveolar ventilation that precede a visible drop in respiratory rate. **Analysis of Incorrect Options:** * **B. Respiratory Depression:** This occurs at higher serum levels (12–15 mEq/L). While it is a classic sign, it follows the loss of reflexes and the initial drop in $SpO_2$. * **C. Cardiac Arrest:** This is a late and terminal sign of toxicity, typically occurring when serum levels exceed 25 mEq/L. * **D. Anuria:** Magnesium is excreted solely by the kidneys. While oliguria/anuria is a **predisposing factor** that leads to toxicity (due to accumulation), it is not a sign of the toxicity itself. **High-Yield Clinical Pearls for NEET-PG:** * **Order of Toxicity:** $SpO_2$ drop → Loss of Patellar Reflex (8–10 mEq/L) → Respiratory Depression (12–15 mEq/L) → Cardiac Arrest (>25 mEq/L). * **Monitoring:** Always check urine output (>30 ml/hr), respiratory rate (>12/min), and presence of knee jerk before every dose. * **Antidote:** 10 ml of 10% **Calcium Gluconate** administered IV over 10 minutes.

Q: Which of the following statements regarding cholestasis of pregnancy is FALSE?

Serum bilirubin is elevated above 5 mg/dL. **Intrahepatic Cholestasis of Pregnancy (ICP)** is a reversible form of hormonal cholestasis occurring in the late second or third trimester, characterized by intense pruritus and elevated serum bile acids. ### **Explanation of Options:** * **Option A (Correct Answer):** In ICP, while serum bilirubin may be elevated, it is **rarely above 2–5 mg/dL**. A bilirubin level exceeding 5 mg/dL is highly unusual and should prompt an investigation for other causes like viral hepatitis, biliary obstruction, or hemolysis. * **Option B:** Transaminases (ALT/AST) are typically elevated in ICP but remain relatively low compared to viral hepatitis. They are usually **less than 250 IU/L**, though they can occasionally reach up to 500 IU/L. * **Option C:** Pruritus (typically involving palms and soles) is the hallmark symptom and often **precedes the elevation of biochemical markers** (bile acids and LFTs) by several weeks. * **Option D:** ICP is associated with **dyslipidemia**, specifically an increase in total cholesterol, LDL, and triglycerides, likely due to the metabolic impact of cholestasis on lipid processing. ### **Clinical Pearls for NEET-PG:** * **Gold Standard Investigation:** Elevated **Serum Bile Acids (>10 μmol/L)** is the most sensitive and specific marker. * **Drug of Choice:** **Ursodeoxycholic Acid (UDCA)** – it improves pruritus and lowers bile acid levels. * **Fetal Risks:** ICP is associated with an increased risk of **meconium-stained amniotic fluid, preterm labor, and sudden intrauterine fetal death (IUFD)**, especially when bile acids exceed 40–100 μmol/L. * **Postpartum:** Symptoms and lab values typically resolve within 2–4 weeks after delivery. If they persist, consider primary biliary cholangitis.

Q: What is the primary cause of knots in the umbilical cord?

Fetal movement. ### Explanation **Primary Concept:** True knots of the umbilical cord (*cordis nodus*) occur in approximately 1% of deliveries. The primary etiology is **active fetal movement**, particularly during the second trimester when the volume of amniotic fluid is relatively high compared to the fetus, allowing the fetus to pass through a loop of the cord. **Why Option A is Correct:** Fetal activity is the driving force. Factors that facilitate this include a **long umbilical cord**, polyhydramnios, and small fetal size (allowing more room for maneuvers). While most knots remain loose and asymptomatic, they can tighten during descent in labor. **Analysis of Incorrect Options:** * **Option B:** While a *tight* knot can lead to venous congestion or arterial occlusion, the presence of a knot itself is not a "high risk" for stillbirth in most cases. The perinatal mortality rate is increased (approx. 4-fold), but the majority of cases result in live births. * **Option C:** This is a distractor. Knots are most dangerous in **monoamniotic** twins (not diamniotic) due to cord entanglement between the two fetuses sharing a single sac. * **Option D:** A true knot is **not** an absolute indication for a Cesarean section. Many are diagnosed incidentally postpartum. Management involves close fetal monitoring (CTG); surgery is only indicated if there are signs of fetal distress (e.g., variable decelerations). **High-Yield NEET-PG Pearls:** * **False Knots:** These are simply redundant folds of umbilical vessels or focal accumulations of Wharton’s jelly; they have no clinical significance. * **Risk Factors:** Multiparity, long cords, and monoamniotic twins. * **Diagnosis:** On Color Doppler, a true knot may show the **"hanging man sign."** * **Clinical Sign:** Look for **variable decelerations** on the CTG during labor if the knot tightens.

Q: Recurrent abortion in the first trimester is most often due to what cause?

Chromosomal abnormalities. **Explanation:** **1. Why Chromosomal Abnormalities are the Correct Answer:** Chromosomal abnormalities are the single most common cause of spontaneous pregnancy loss, especially in the **first trimester** (up to 12 weeks). In cases of recurrent pregnancy loss (RPL), parental chromosomal rearrangements (like balanced translocations) or sporadic embryonic aneuploidy account for the majority of early losses. Among these, **Autosomal Trisomy** is the most frequent specific chromosomal anomaly found in abortuses, followed by Monosomy X (Turner syndrome) and Polyploidy. **2. Analysis of Incorrect Options:** * **B. Uterine Anomaly:** Structural issues (e.g., septate uterus, cervical incompetence, or fibroids) are significant causes of recurrent abortion but are more characteristically associated with **second-trimester** losses rather than early first-trimester ones. * **C. Hormonal Disturbance:** Conditions like Luteal Phase Defect (LPD), uncontrolled Diabetes Mellitus, and Thyroid disorders can cause miscarriage. However, statistically, they occur less frequently than genetic factors in the first trimester. * **D. Infection:** While certain infections (TORCH, Mycoplasma) can cause sporadic pregnancy loss, they are **rarely** a cause of recurrent abortion, as the mother usually develops immunity after the initial exposure. **3. Clinical Pearls for NEET-PG:** * **Most common Trisomy in abortus:** Trisomy 16. * **Most common single chromosomal anomaly:** Monosomy X (45,X). * **Investigation of choice for RPL:** Karyotyping of both parents to rule out balanced translocations. * **Timing:** If the question specifies "Second Trimester," the most common cause shifts toward **Anatomical/Uterine factors** (specifically Cervical Incompetence).

Q: Which one of the following causes the greatest risk of ectopic pregnancy?

Previous ectopic pregnancy. **Explanation:** The risk of ectopic pregnancy is primarily determined by the degree of damage to the fallopian tube. **1. Why "Previous Ectopic Pregnancy" is correct:** A history of a previous ectopic pregnancy is the **strongest risk factor**, increasing the risk by approximately **10 to 15 times** compared to the general population. If a patient has had two or more prior ectopic pregnancies, the risk escalates to over 25%. This is due to underlying tubal pathology, scarring from previous surgery (salpingostomy), or persistent functional impairment of the cilia. **2. Analysis of Incorrect Options:** * **Pelvic Inflammatory Disease (PID):** While PID is the **most common** cause of ectopic pregnancy due to post-inflammatory tubal scarring and adhesions, it does not carry as high a relative risk as a prior ectopic event. * **IUD Use:** IUDs are highly effective contraceptives. They do not *cause* ectopic pregnancy; however, if a woman becomes pregnant with an IUD in situ, the **proportion** of those pregnancies being ectopic is higher. In absolute terms, IUD users have a lower risk of ectopic pregnancy than women using no contraception. * **Previous MTP:** Uncomplicated Medical Termination of Pregnancy (MTP) does not significantly increase the risk. Only if the procedure was complicated by post-abortal sepsis leading to tubal damage would the risk increase. **Clinical Pearls for NEET-PG:** * **Strongest Risk Factor:** Previous ectopic pregnancy. * **Most Common Cause:** Pelvic Inflammatory Disease (Chlamydia is the most common organism). * **Other High-Risk Factors:** Tubal reconstructive surgery, DES exposure in utero, and smoking (impairs ciliary motility). * **Classic Triad:** Amenorrhea, abdominal pain, and vaginal bleeding (seen in only 50% of cases).

Q: A woman presents with amenorrhea of 2 months duration, lower abdominal pain, facial pallor, fainting, and shock. What is the most likely diagnosis?

Ruptured ectopic pregnancy. **Explanation:** The clinical presentation described is a classic medical emergency in early pregnancy. The correct diagnosis is **Ruptured Ectopic Pregnancy** based on the "Classic Triad" and signs of hemodynamic instability. **1. Why Ruptured Ectopic Pregnancy is Correct:** The patient presents with the hallmark features: **amenorrhea** (indicating pregnancy), **acute abdominal pain**, and **hypovolemic shock** (pallor, fainting, hypotension). In a ruptured ectopic pregnancy, the fallopian tube (most common site) bursts, leading to massive intraperitoneal hemorrhage (hemoperitoneum). This rapid blood loss causes the shock and fainting (syncope) described. **2. Why Other Options are Incorrect:** * **Ruptured Ovarian Cyst:** While it causes acute pain and potential hemoperitoneum, it is usually not associated with amenorrhea or a positive pregnancy status. * **Threatened Abortion:** This presents with vaginal bleeding and mild cramping, but the cervix is closed, and there is no hemodynamic collapse or signs of internal hemorrhage. * **Septic Abortion:** This involves infection of the products of conception. While it can cause shock (septic shock), it is characterized by high-grade fever, foul-smelling vaginal discharge, and exquisite uterine tenderness, rather than sudden fainting and pallor from blood loss. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site of Ectopic Pregnancy:** Ampulla of the Fallopian tube. * **Most common site of Rupture:** Isthmus (occurs earlier, around 6–8 weeks). * **Gold Standard Investigation:** Transvaginal Ultrasound (TVUS) + Serum $\beta$-hCG (Correlation of "Discriminatory Zone"). * **Management of Rupture:** Immediate resuscitation followed by **emergency laparotomy** (Salpingectomy). * **Kehr’s Sign:** Referred pain to the shoulder due to diaphragmatic irritation by blood—a classic sign of ruptured ectopic pregnancy.

Q: Twin pregnancy predisposes to which of the following complications?

All of the above. **Explanation:** Twin pregnancy is a high-risk condition because the presence of more than one fetus significantly increases the physiological and mechanical demands on the maternal system. * **Hydramnios (Polyhydramnios):** This occurs in approximately 10% of twin pregnancies. It is often associated with Twin-to-Twin Transfusion Syndrome (TTTS) in monochorionic twins, where the recipient twin develops polyuria. It can also result from an increased total fetal urine output due to the presence of two fetuses. * **Pregnancy-Induced Hypertension (PIH):** The risk of PIH and preeclampsia is 2–3 times higher in multifetal gestations. This is attributed to the increased placental mass (hyperplacentosis), which leads to a higher release of anti-angiogenic factors (like sFlt-1) into the maternal circulation. * **Malpresentation:** Due to the limited intrauterine space and the presence of two fetuses, the likelihood of at least one twin being in a non-cephalic position (breech or transverse) is high. Only about 40–50% of twin pregnancies present with both fetuses in the cephalic position. **Conclusion:** Since all the listed conditions are recognized complications of multifetal gestation, **Option D** is the correct answer. **High-Yield NEET-PG Pearls:** * **Most common complication:** Preterm labor/prematurity. * **Most common presentation:** Cephalic-Cephalic (Vertex-Vertex). * **Anemia:** Iron deficiency anemia is more common due to increased fetal demand. * **Postpartum Hemorrhage (PPH):** Increased risk due to uterine overdistension leading to atony.

Q: The placenta, anchored to the myometrium partially or completely without any intervening decidua, is called what?

Placenta accreta. **Explanation:** The question describes **Placenta Accreta**, a condition characterized by an abnormal adherence of the placenta to the uterine wall. The fundamental pathology is the **partial or complete absence of the decidua basalis** (specifically the Nitabuch’s layer), which normally acts as a barrier. Without this layer, the chorionic villi attach directly to the surface of the myometrium. **Analysis of Options:** * **Placenta Accreta (Correct):** Villi are attached directly to the **surface** of the myometrium without invading it. It is the most common type (approx. 75-80% of cases). * **Placenta Increta:** Villi **invade into** the myometrium. * **Placenta Percreta:** Villi **penetrate through** the entire thickness of the myometrium and may invade serosa or adjacent organs like the bladder. * **Placenta Succenturiata:** This is a morphological variation where one or more small accessory lobes of placenta are developed in the membranes at a distance from the main peripheral margin. It is not an invasive disorder. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factors:** The most significant risk factors are a **previous Cesarean section** and **Placenta Previa**. The risk increases linearly with the number of prior C-sections. * **Clinical Presentation:** Often presents as a "retained placenta" or profuse hemorrhage during the third stage of labor when the placenta fails to separate. * **Diagnosis:** Antenatally diagnosed via Ultrasound/Color Doppler (look for "placental lacunae" or loss of the retroplacental hypoechoic zone). * **Management:** The standard treatment for confirmed placenta accreta spectrum is a planned **Cesarean Hysterectomy**.

Question 1

What is the earliest sign of magnesium toxicity?

Accepted Answer

Falling oxygen saturation on pulse oximetry

Answer

Respiratory depression

Answer

Cardiac arrest

Answer

Anuria

Question 2

Which of the following statements regarding cholestasis of pregnancy is FALSE?

Accepted Answer

Serum bilirubin is elevated above 5 mg/dL

Answer

Alanine aminotransferase (ALT) is less than 250 IU/L

Answer

Pruritus precedes abnormal laboratory values by weeks

Answer

Dyslipidemia is associated

Question 3

The 'double set up examination' is concerned with which of the following conditions?

Accepted Answer

Placenta previa

Answer

Manual removal of placenta

Answer

Twin pregnancy

Answer

Bicornuate uterus

Question 4

What is the primary cause of knots in the umbilical cord?

Accepted Answer

Fetal movement

Answer

High risk of stillbirth

Answer

Dangerous in diamniotic twins

Answer

Always an indication for Cesarean section

Question 5

A patient at 22 weeks gestation is diagnosed with IUD which occurred at 17 weeks but did not have a miscarriage. This patient is at increased risk for which of the following?

Accepted Answer

Consumptive coagulopathy with hypofibrinogenemia

Answer

Septic abortion

Answer

Recurrent abortion

Answer

Future infertility

Question 6

Recurrent abortion in the first trimester is most often due to what cause?

Accepted Answer

Chromosomal abnormalities

Answer

Uterine anomaly

Answer

Hormonal disturbance

Answer

Infection

Question 7

Which one of the following causes the greatest risk of ectopic pregnancy?

Accepted Answer

Previous ectopic pregnancy

Answer

Pelvic inflammatory disease

Answer

IUD use

Answer

Previous MTP

Question 8

A woman presents with amenorrhea of 2 months duration, lower abdominal pain, facial pallor, fainting, and shock. What is the most likely diagnosis?

Accepted Answer

Ruptured ectopic pregnancy

Answer

Ruptured ovarian cyst

Answer

Threatened abortion

Answer

Septic abortion

Question 9

Twin pregnancy predisposes to which of the following complications?

Accepted Answer

All of the above

Answer

Hydramnios

Answer

Pregnancy-induced hypertension

Answer

Malpresentation

Question 10

The placenta, anchored to the myometrium partially or completely without any intervening decidua, is called what?

Accepted Answer

Placenta accreta

Answer

Placenta increta

Answer

Placenta succenturia

Answer

Placenta percreta

Maternal-Fetal Medicine — MCQs

Maternal-Fetal Medicine — MCQs

On this page

Practice by Chapter

Want unlimited practice?