Labor and Delivery — MCQs

Labor and Delivery Indian Medical PG Practice Questions and MCQs

Question 491: Which of the following correctly defines Montevideo units for measurement of uterine activity?

A. Uterine pressure (mm of Hg) multiplied by the number of contractions in 10 minutes. (Correct Answer)
B. Uterine pressure (mm of water) multiplied by the number of contractions in 10 minutes.
C. Uterine pressure (cm of water) multiplied by the number of contractions in 10 minutes.
D. Uterine pressure (cm of H2O) multiplied by the number of contractions in 20 minutes.

Explanation: **Explanation:** **Montevideo Units (MVUs)** are the gold standard for quantifying uterine activity during labor. They are calculated by taking the **peak uterine pressure** (measured in **mmHg**) during a contraction, subtracting the resting baseline tone, and multiplying this value by the **number of contractions in a 10-minute window**. 1. **Why Option A is Correct:** The definition specifically requires pressure in **mmHg** (the standard unit for intrauterine pressure catheters) and a time frame of **10 minutes**. For example, if a woman has 3 contractions in 10 minutes, each reaching a peak pressure of 50 mmHg (above baseline), the activity is 150 MVUs. 2. **Why Other Options are Incorrect:** * **Options B & C:** These use "mm of water" or "cm of water." While these are units of pressure, clinical obstetrics standardizes uterine activity using mercury (Hg) to remain consistent with blood pressure and intrauterine pressure catheter (IUPC) calibrations. * **Option D:** This uses a 20-minute interval and "cm of H2O," both of which are mathematically and clinically incorrect for the standard MVU formula. **High-Yield Clinical Pearls for NEET-PG:** * **Adequate Labor:** Spontaneous labor is generally considered "adequate" when uterine activity reaches **200–250 MVUs**. * **Clinical Utility:** MVUs are only measurable via an **Internal Intrauterine Pressure Catheter (IUPC)**; they cannot be calculated using external tocodynamometry. * **Arrest of Labor:** Before diagnosing an arrest of the active phase in the first stage of labor, one must ensure that contractions are adequate (≥200 MVUs) for at least 4 hours.

Question 492: For the prevention of preterm labor in a patient with a history of preterm delivery, which of the following is used?

A. Calcium supplements
B. Ecosprin
C. Progesterone (Correct Answer)
D. Steroids

Explanation: **Explanation:** **1. Why Progesterone is Correct:** Progesterone is essential for maintaining "uterine quiescence." It inhibits the production of pro-inflammatory cytokines and prostaglandins, thereby preventing cervical ripening and uterine contractions. In women with a **documented history of spontaneous preterm birth (sPTB)**, progesterone supplementation (typically 17-OHP caproate or vaginal progesterone) has been shown to significantly reduce the risk of recurrence. It is the standard of care for secondary prevention of preterm labor. **2. Why Other Options are Incorrect:** * **A. Calcium supplements:** While calcium is vital for maternal bone health and may play a role in reducing the risk of pre-eclampsia, it has no proven role in preventing preterm labor. * **B. Ecosprin (Low-dose Aspirin):** This is used primarily for the prevention of **Pre-eclampsia** and Fetal Growth Restriction (FGR) in high-risk patients. It does not prevent preterm labor directly. * **C. Steroids (Corticosteroids):** These are used for **fetal lung maturity** once preterm labor is *imminent* (between 24–34 weeks). They do not prevent the onset of labor; they reduce neonatal morbidity (RDS, IVH, NEC) after the birth. **3. High-Yield Clinical Pearls for NEET-PG:** * **Screening:** In patients with a history of sPTB, **Transvaginal Ultrasound (TVS)** for cervical length (CL) is performed. If CL <25 mm before 24 weeks, it is a strong predictor of preterm birth. * **Management:** * **History of sPTB:** Progesterone is indicated. * **Short Cervix (<25mm) + History of sPTB:** Consider **Cervical Cerclage** (McDonald or Shirodkar). * **Short Cervix (<25mm) + No History:** Vaginal progesterone is the preferred treatment. * **Tocolytics:** (e.g., Nifedipine, Atosiban) are used to delay delivery for 48 hours to allow steroid action, not for long-term prevention.

Question 493: External cephalic version (ECV) is contraindicated in which of the following conditions?

A. Primigravida
B. Flexed breech presentation
C. Severe anemia
D. Pregnancy-induced hypertension (PIH) (Correct Answer)

Explanation: ### Explanation **Correct Option: D. Pregnancy-induced hypertension (PIH)** External Cephalic Version (ECV) is a procedure where the fetus is manually rotated from a non-vertex presentation to a vertex presentation through the maternal abdominal wall. **Why PIH is the correct answer:** PIH (including Preeclampsia) is a **relative or absolute contraindication** for ECV depending on severity. The primary concern is that PIH is often associated with **uteroplacental insufficiency** and an increased risk of **abruptio placentae**. The physical manipulation involved in ECV can trigger placental separation or cause acute fetal distress in a fetus already compromised by reduced placental perfusion. Furthermore, any condition where a vaginal delivery is contraindicated or where the risk of emergency Cesarean section is high makes ECV unfavorable. **Analysis of Incorrect Options:** * **A. Primigravida:** Being a primigravida is **not** a contraindication. While the success rate of ECV is lower in primigravidae (due to a tighter abdominal wall and uterus) compared to multiparous women, it is still routinely performed to reduce the risk of a primary Cesarean section. * **B. Flexed breech presentation:** This is actually the **ideal** type of breech for a successful ECV. It is much easier to rotate a fetus in a complete or flexed breech than one in a frank breech (where the legs act as splints). * **C. Severe anemia:** While severe anemia requires clinical management, it is not a direct contraindication to the mechanical rotation of the fetus. **High-Yield Clinical Pearls for NEET-PG:** * **Timing:** ECV is typically performed at **36 weeks** in primigravidae and **37 weeks** in multiparae (to allow for spontaneous version and ensure fetal maturity if emergency delivery is needed). * **Absolute Contraindications:** Placenta previa, previous classical Cesarean section, ruptured membranes (oligohydramnios), multiple gestation, and non-reassuring fetal heart rate patterns. * **Prerequisites:** Reactive NST, adequate liquor (AFI > 5), and a relaxed uterus (often achieved using tocolytics like **Ritodrine or Salbutamol**). * **Success Rate:** Approximately 50-60%.

Question 494: A pregnant woman in her 32nd week of gestation is given magnesium sulfate for pre-eclampsia. What is the earliest clinical indication of hypermagnesemia?

A. Loss of deep tendon reflexes (Correct Answer)
B. Flaccid paralysis
C. Respiratory arrest
D. Hypotension

Explanation: **Explanation:** Magnesium sulfate ($MgSO_4$) is the drug of choice for seizure prophylaxis in pre-eclampsia and control in eclampsia. It acts as a CNS depressant and a neuromuscular blocker by inhibiting acetylcholine release at the motor endplate. Because it is excreted solely by the kidneys, toxicity (hypermagnesemia) is a significant risk, especially in patients with renal impairment. **Why Option A is Correct:** The **loss of deep tendon reflexes (patellar reflex/knee jerk)** is the **earliest clinical sign** of magnesium toxicity. It occurs when serum magnesium levels reach **7–10 mEq/L** (Normal therapeutic range is 4–7 mEq/L). The loss of reflexes serves as a crucial "warning sign" that precedes more severe life-threatening complications. **Analysis of Incorrect Options:** * **B. Flaccid paralysis:** This occurs at higher levels (usually >10–12 mEq/L) as neuromuscular blockade intensifies, leading to generalized muscle weakness. * **C. Respiratory arrest:** This is a late and fatal sign, typically occurring when levels exceed **12–15 mEq/L** due to paralysis of the diaphragm and intercostal muscles. * **D. Hypotension:** While $MgSO_4$ causes vasodilation, hypotension is an inconsistent finding and not the primary clinical marker used to monitor for toxicity. **NEET-PG High-Yield Pearls:** * **Monitoring:** Always monitor **Respiratory Rate** (>12/min), **Urine Output** (>30 ml/hr), and **Patellar Reflex** during administration. * **Antidote:** The immediate management for toxicity is **10 ml of 10% Calcium Gluconate** IV (administered over 10 minutes). * **Cardiac Arrest:** Occurs at levels >25 mEq/L. * **Therapeutic Level:** 4.8–8.4 mg/dL (or 4–7 mEq/L).

Question 495: What is an absolute indication for caesarean section?

A. Previous lower segment caesarean section (LSCS)
B. Type IV placenta previa (Correct Answer)
C. Fetal distress
D. Breech presentation

Explanation: **Explanation:** In Obstetrics, indications for Caesarean Section (CS) are categorized into **Absolute** (vaginal delivery is impossible or life-threatening) and **Relative** (vaginal delivery is possible but carries higher risk). **Why Type IV Placenta Previa is the Correct Answer:** Type IV (Total/Central) Placenta Previa occurs when the placenta completely covers the internal os of the cervix. As the cervix dilates or the lower segment stretches, massive, life-threatening maternal hemorrhage is inevitable. Furthermore, the fetus cannot bypass the placenta to enter the birth canal. Therefore, a vaginal delivery is physically impossible and contraindicated, making it a classic **absolute indication** for CS. **Analysis of Incorrect Options:** * **A. Previous LSCS:** This is a relative indication. Many women are candidates for **VBAC** (Vaginal Birth After Cesarean) or **TOLAC** (Trial of Labor After Cesarean) if the previous incision was a lower segment transverse type and no other contraindications exist. * **C. Fetal Distress:** While often requiring an emergency CS, it is not "absolute." In some cases, if the head is low and delivery is imminent, an operative vaginal delivery (forceps/ventouse) can be performed faster than a CS. * **D. Breech Presentation:** This is a relative indication. Vaginal Breech Delivery is possible in specific circumstances (e.g., frank breech, adequate pelvis, multipara) though CS is often preferred for safety. **High-Yield Clinical Pearls for NEET-PG:** * **Other Absolute Indications:** Cephalopelvic Disproportion (CPD), Pelvic outlet contraction, Central Placenta Previa, and Pelvic tumors obstructing the birth canal (e.g., large cervical fibroid). * **Placenta Previa Grading:** Type III (incomplete central) and Type IV (complete central) both strictly require CS. * **Stallworthy’s Sign:** A drop in fetal heart rate when the head is pushed into the pelvis, seen in posterior placenta previa (Type II posterior).

Question 496: Pelvic examination is not indicated in which of the following conditions?

A. Placenta previa (Correct Answer)
B. Contracted pelvis
C. Hydatidiform mole
D. Ectopic pregnancy

Explanation: In cases of **Placenta Previa**, the placenta is implanted in the lower uterine segment, covering or near the internal os. Performing a digital pelvic examination (PV) can inadvertently detach the placenta or traumatize the highly vascularized placental bed, leading to **sudden, torrential, and life-threatening hemorrhage**. Therefore, a PV examination is strictly contraindicated unless performed in an "Operation Theatre" under double setup (prepared for immediate Cesarean section). The gold standard for diagnosis is a Transvaginal Ultrasound (TVS), which is safe and accurate. **Explanation of Incorrect Options:** * **Contracted Pelvis:** Pelvic examination (Clinical Pelvimetry) is essential here to assess the pelvic diameters (e.g., diagonal conjugate, ischial spines) and determine the feasibility of vaginal delivery. * **Hydatidiform Mole:** While diagnosis is primarily via USG ("snowstorm appearance") and beta-hCG levels, a PV examination is not contraindicated and may reveal a "doughy" uterus or the presence of theca lutein cysts. * **Ectopic Pregnancy:** A bimanual examination is a standard clinical step to check for cervical motion tenderness (Chandelier sign) and adnexal masses, though it must be performed gently to avoid rupturing the sac. **High-Yield Clinical Pearls for NEET-PG:** * **Warning Hemorrhage:** The first episode of bleeding in placenta previa is usually painless, causeless, and recurrent. * **Rule of Thumb:** In any patient presenting with antepartum hemorrhage (APH), **always** perform a speculum examination to rule out local causes, but **never** perform a digital PV until placenta previa is ruled out by ultrasound. * **Stallworthy’s Sign:** Posterior placenta previa can interfere with the engagement of the fetal head, a classic clinical finding.

Question 497: A pregnant mother at 32 weeks gestation presents in preterm labor. Antenatal steroids to induce lung maturity in the fetus may be given in all of the following conditions except?

A. Prolonged rupture of membranes for more than 24 hours
B. Pregnancy-induced hypertension
C. Diabetes mellitus
D. Chorioamnionitis (Correct Answer)

Explanation: **Explanation:** The primary goal of antenatal corticosteroids (ACS) is to accelerate fetal lung maturity and reduce the risk of Respiratory Distress Syndrome (RDS), Intraventricular Hemorrhage (IVH), and Necrotizing Enterocolitis (NEC) in preterm births. **Why Chorioamnionitis is the Correct Answer:** Chorioamnionitis is a clinical diagnosis of intrauterine infection. In this condition, the intrauterine environment is hostile, and the risk of maternal and fetal sepsis is high. The definitive management is **immediate delivery** regardless of gestational age. Delaying delivery for 48 hours to complete a course of steroids is contraindicated as it increases the risk of life-threatening maternal and neonatal sepsis. Furthermore, the use of steroids (immunosuppressants) in the presence of active infection is generally avoided. **Analysis of Incorrect Options:** * **Prolonged Rupture of Membranes (PROM):** ACS are indicated in PPROM (Preterm Premature Rupture of Membranes) between 24 and 34 weeks to reduce neonatal morbidity, provided there are no signs of infection. * **Pregnancy-Induced Hypertension (PIH):** PIH is not a contraindication. In fact, if delivery is anticipated due to worsening pre-eclampsia, steroids are essential to improve fetal outcomes. * **Diabetes Mellitus:** Diabetes is not a contraindication. However, clinicians must closely monitor maternal blood glucose levels as steroids can cause transient hyperglycemia, often requiring an adjustment in insulin dosage. **High-Yield Clinical Pearls for NEET-PG:** * **Standard Regimen:** Betamethasone (12 mg IM, 2 doses, 24 hours apart) or Dexamethasone (6 mg IM, 4 doses, 12 hours apart). * **Window of Efficacy:** Maximum benefit is seen if delivery occurs between 24 hours and 7 days after the first dose. * **Gestational Age:** Recommended for women at risk of preterm birth between **24 and 34 weeks**. * **Contraindications:** Clinical chorioamnionitis is the most significant absolute contraindication.

Question 498: What is an absolute indication for cesarean section?

A. Previous uterine scar
B. Transverse lie
C. Breech presentation
D. Vaginal atresia (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. Vaginal atresia** In obstetrics, an **absolute indication** for a Cesarean Section (CS) refers to a clinical scenario where vaginal delivery is physically impossible or poses an immediate, life-threatening risk to the mother or fetus. **Vaginal atresia** (congenital absence or closure of the vagina) is an absolute indication because the birth canal is structurally non-existent or obstructed. There is no anatomical pathway for the fetus to descend, making abdominal delivery the only possible route. **Why the other options are incorrect:** * **A. Previous uterine scar:** This is a **relative indication**. Many women with one previous lower segment cesarean section (LSCS) can safely undergo a **Trial of Labor After Cesarean (TOLAC)**, leading to a Vaginal Birth After Cesarean (VBAC). * **B. Transverse lie:** While a persistent transverse lie at term requires a CS, it is not always "absolute" because external cephalic version (ECV) can sometimes be attempted to convert the fetus to a longitudinal lie, or the fetus may spontaneously convert before labor. * **C. Breech presentation:** This is a **relative indication**. Depending on the type of breech (e.g., frank breech), fetal weight, and pelvic adequacy, a planned vaginal breech delivery is an acceptable clinical option in specific cases. **High-Yield Clinical Pearls for NEET-PG:** * **Other Absolute Indications:** Central Placenta Previa (Grade IV), Cephalopelvic Disproportion (CPD), Pelvic exostosis/tumors obstructing the birth canal, and Advanced invasive Cervical Cancer. * **Most common indication for CS worldwide:** Previous CS. * **Most common indication for primary CS:** Dystocia (Failure to progress). * **Vaginal Atresia** is often associated with **Müllerian Agenesis (MRKH Syndrome)**; however, if a pregnancy occurs (via ART/surrogacy or in cases of partial atresia), the delivery must be abdominal.

Question 499: In a patient with a prosthetic heart valve, at which gestational age is it generally recommended to switch from warfarin to heparin?

A. 28 weeks
B. 32 weeks
C. 36 weeks (Correct Answer)
D. Postpartum

Explanation: **Explanation:** The management of anticoagulation in pregnant women with prosthetic heart valves is a critical balance between preventing maternal valve thrombosis and minimizing fetal/neonatal risks. **Why 36 weeks is correct:** Warfarin is a highly effective anticoagulant but crosses the placenta. The primary concern near term is the risk of **fetal intracranial hemorrhage** during the mechanical stress of labor and delivery if the fetus is anticoagulated. Therefore, it is standard practice to switch from Warfarin to **Unfractionated Heparin (UFH) or Low Molecular Weight Heparin (LMWH)** at **36 weeks** of gestation. Heparin does not cross the placenta, ensuring the fetus is not anticoagulated during birth. Additionally, UFH has a short half-life and can be easily reversed with Protamine Sulfate if urgent delivery is required. **Analysis of Incorrect Options:** * **A & B (28 and 32 weeks):** Switching this early unnecessarily increases the risk of maternal valve thrombosis. Warfarin is generally superior to heparin for preventing valve thrombosis; thus, it is continued as long as safely possible. * **D (Postpartum):** Waiting until postpartum is dangerous. If the patient goes into labor while on Warfarin, the risk of neonatal hemorrhage is extremely high. Warfarin is typically restarted 6–12 hours after an uncomplicated delivery. **Clinical Pearls for NEET-PG:** * **Warfarin Embryopathy:** Occurs if Warfarin is used between **6–12 weeks** (stippled epiphyses, nasal hypoplasia). * **Preferred Regimen:** Many guidelines suggest Warfarin throughout pregnancy (if dose <5mg) due to lower valve failure rates, but **switching at 36 weeks is mandatory** regardless of the dose. * **Labor Management:** Heparin should be discontinued 4–6 hours (UFH) or 24 hours (LMWH) before planned induction or regional anesthesia.

Question 500: Placenta previa is characterized by all of the following except?

A. Painless bleeding
B. Causeless bleeding
C. Presents in first trimester (Correct Answer)
D. Recurrent bleeding

Explanation: **Explanation:** Placenta previa is a condition where the placenta is implanted in the lower uterine segment, partially or completely covering the internal os. It is a classic cause of **Antepartum Hemorrhage (APH)**. **Why Option C is the correct answer:** Placenta previa typically presents in the **late second or third trimester** (usually after 28 weeks of gestation). This is because the lower uterine segment begins to form and stretch during this period, causing the placental attachments to shear and bleed. Bleeding in the first trimester is categorized as an abortion, ectopic pregnancy, or molar pregnancy, not placenta previa. **Analysis of other options:** * **Painless bleeding (Option A):** This is the hallmark of placenta previa. Unlike placental abruption, the bleeding occurs without uterine contractions or pain. * **Causeless bleeding (Option B):** The bleeding usually occurs spontaneously without any preceding trauma or obvious inciting factor. * **Recurrent bleeding (Option D):** Bleeding episodes often recur as the lower segment continues to stretch and the cervix begins to efface as term approaches. The first episode (warning hemorrhage) is usually mild. **High-Yield Clinical Pearls for NEET-PG:** * **Diagnosis:** Transvaginal Ultrasound (TVS) is the gold standard for localization. * **Contraindication:** **Digital vaginal examination** is strictly contraindicated unless the patient is in the operating theater (Double Setup Examination), as it can provoke torrential hemorrhage. * **Stallworthy’s Sign:** A clinical finding where the fetal heart rate slows when the head is pushed into the pelvis, suggesting a posterior placenta previa. * **Risk Factors:** Multiparity, advanced maternal age, and previous Cesarean section (increases risk of Placenta Accreta Spectrum).

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Physiology of Labor

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Stages of Labor and Normal Progression

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Fetal Monitoring Techniques

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Pain Management in Labor

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Induction and Augmentation of Labor

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Operative Delivery (Forceps and Vacuum)

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Cesarean Section: Indications and Techniques

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Dystocia and Abnormal Labor Patterns

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Obstetric Emergencies

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Postpartum Hemorrhage Management

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