Labor and Delivery — MCQs

Labor and Delivery Indian Medical PG Practice Questions and MCQs

Question 151: What is the commonest cause of perinatal mortality in twins?

A. Prematurity (Correct Answer)
B. Infection
C. Head injury
D. Malnutrition

Explanation: **Explanation:** **1. Why Prematurity is Correct:** Prematurity is the single most significant factor contributing to perinatal mortality and morbidity in twin gestations. While the average singleton pregnancy lasts 40 weeks, the average twin pregnancy lasts approximately 37 weeks. About 50% of twins are born preterm (before 37 weeks), and nearly 10% are born very preterm (before 32 weeks). The complications associated with prematurity—specifically **Respiratory Distress Syndrome (RDS)**, intraventricular hemorrhage, and necrotizing enterocolitis—are the primary drivers of neonatal death in these cases. **2. Why Other Options are Incorrect:** * **Infection:** While chorioamnionitis or neonatal sepsis can occur, they are often secondary to prolonged rupture of membranes or consequences of prematurity itself, rather than the primary statistical cause of death. * **Head Injury:** Birth trauma (like intracranial hemorrhage) was more common historically due to difficult vaginal deliveries of the second twin. However, with modern obstetric management and increased C-section rates for malpresentations, it is now a rare cause of mortality. * **Malnutrition:** While **Intrauterine Growth Restriction (IUGR)** and discordant growth are common in twins (especially Monochorionic), they typically lead to morbidity rather than being the leading cause of mortality compared to the systemic failures of prematurity. **High-Yield Clinical Pearls for NEET-PG:** * **Average duration of pregnancy:** Singletons (40 weeks), Twins (37 weeks), Triplets (33 weeks), Quadruplets (29 weeks). * **Monochorionic twins** have a 3–5 times higher mortality rate than dichorionic twins due to unique complications like **Twin-to-Twin Transfusion Syndrome (TTTS)**. * The **second twin** is generally at a higher risk of hypoxia and birth trauma than the first twin. * **Most common malpresentation in twins:** Cephalic-Cephalic (approx. 40-45%).

Question 152: A 3,800-gram male infant is delivered vaginally after a shoulder dystocia was encountered. If a neonatal injury is suspected, what is the likely finding in the infant?

A. Arm that is at its side and internally rotated (Correct Answer)
B. Arm that is fixed and flexed and hypotonic
C. Dislocated elbow
D. Clavicle fracture

Explanation: **Explanation:** The clinical scenario describes a classic complication of **shoulder dystocia**: traction on the fetal head during delivery leading to **Erb’s Palsy**. This is the most common neonatal injury associated with shoulder dystocia, resulting from damage to the upper trunk of the brachial plexus (**C5-C6 nerve roots**). **1. Why Option A is Correct:** Damage to C5-C6 affects the axillary, suprascapular, and musculocutaneous nerves. This leads to paralysis of the deltoid, supraspinatus, infraspinatus, and biceps brachii. The characteristic clinical posture is the **"Waiters Tip" deformity**: * **Adduction and Internal Rotation** of the arm (due to paralyzed abductors and external rotators). * **Extension of the elbow** (due to paralyzed biceps). * **Pronation of the forearm.** **2. Why Other Options are Incorrect:** * **Option B:** A fixed, flexed, and hypotonic arm does not match the specific dermatomal pattern of Erb’s palsy. * **Option C:** Dislocated elbows are rare birth injuries and are not typically associated with the traction forces of shoulder dystocia. * **Option D:** While **Clavicle fracture** is the most common *bone* injury in shoulder dystocia, Erb’s palsy (Option A) is a more classic "finding" or "presentation" tested in the context of nerve injury patterns. In many exams, if Erb's palsy is an option, it is the preferred answer for "likely finding" regarding limb posture. **Clinical Pearls for NEET-PG:** * **Klumpke’s Palsy:** Injury to **C8-T1**; presents with a **"Claw hand"** (paralysis of intrinsic hand muscles) and may be associated with Horner’s syndrome. * **Risk Factors for Shoulder Dystocia:** Maternal diabetes, fetal macrosomia (>4000g), and prolonged second stage of labor. * **Management:** The first step is the **McRoberts Maneuver** (hyperflexion of maternal thighs) followed by **Suprapubic pressure**. Avoid fundal pressure as it worsens impaction.

Question 153: What is the most common cause of antepartum hemorrhage (APH)?

A. Placenta previa
B. Abruptio placenta (Correct Answer)
C. Vasa previa
D. Placenta accreta

Explanation: **Explanation:** **Antepartum Hemorrhage (APH)** is defined as bleeding from or into the genital tract occurring from the 28th week of pregnancy until the birth of the baby. **Why Abruptio Placenta is Correct:** Abruptio placenta (premature separation of a normally situated placenta) is the **most common cause** of APH, accounting for approximately **30-35%** of cases. It is clinically characterized by painful vaginal bleeding, uterine tenderness, and increased uterine tone. It is a significant cause of maternal and perinatal morbidity and is frequently associated with pregnancy-induced hypertension (PIH). **Analysis of Incorrect Options:** * **Placenta Previa:** This is the second most common cause of APH (approx. 20-25%). It is characterized by **painless, causeless, and recurrent** bleeding. The placenta is implanted in the lower uterine segment. * **Vasa Previa:** This is a rare but life-threatening condition where fetal vessels run across the internal os. While it causes APH, the bleeding is **fetal in origin**, and it is much less common than abruption. * **Placenta Accreta:** This refers to an abnormal adherence of the placenta to the myometrium. It typically causes **postpartum hemorrhage (PPH)** during the third stage of labor rather than antepartum hemorrhage. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of APH:** Abruptio Placenta. * **Most common cause of DIC in pregnancy:** Abruptio Placenta. * **Couvelaire Uterus:** A complication of severe concealed abruption where blood extravasates into the myometrium. * **Warning Hemorrhage:** A classic feature of Placenta Previa, not Abruption. * **Stallworthy’s Sign:** Associated with posterior placenta previa.

Question 154: Controlled ARM is indicated in which of the following conditions?

A. Intrauterine device (IUD) placement
B. Maternal HIV infection
C. Polyhydramnios (Correct Answer)
D. Genital herpes

Explanation: **Explanation:** **Controlled Artificial Rupture of Membranes (ARM)** is a specialized technique used when there is a high risk of **cord prolapse** or **abruptio placentae** due to a sudden gush of amniotic fluid. 1. **Why Polyhydramnios is correct:** In polyhydramnios, the excessive volume of amniotic fluid keeps the fetal presenting part high and unengaged. A spontaneous or standard ARM would cause a rapid decompression and a "rush" of fluid, which can wash the umbilical cord down (Cord Prolapse) or cause sudden uterine shrinkage leading to premature placental separation (Abruptio Placentae). **Controlled ARM** involves using a needle or a small puncture to allow the fluid to escape slowly and under stabilization, ensuring the presenting part settles into the pelvis gradually. 2. **Why other options are incorrect:** * **Maternal HIV & Genital Herpes:** ARM is generally avoided or delayed in these cases to maintain the integrity of the membranes as long as possible. Intact membranes act as a barrier, reducing the risk of **Vertical Transmission** of the virus to the fetus during labor. * **IUD placement:** This is a contraceptive procedure unrelated to the management of active labor or membrane rupture. **High-Yield Clinical Pearls for NEET-PG:** * **Prerequisites for ARM:** The cervix must be dilated, and the fetal head must be well-applied to the cervix to prevent cord accidents. * **Other indications for Controlled ARM:** High-head at term (unengaged) and Hydramnios. * **Immediate Action Post-ARM:** Always auscultate the **Fetal Heart Rate (FHR)** immediately after rupture to rule out occult cord prolapse. * **Color of Liquor:** ARM also helps in assessing the color of liquor (e.g., meconium-stained, golden yellow in Rh incompatibility, or tobacco juice in IUD).

Question 155: The second stage of labor begins with which of the following events?

A. Complete cervical dilatation (Correct Answer)
B. Expulsion of the fetus
C. Expulsion of the placenta
D. Internal rotation of the fetal head

Explanation: The stages of labor are defined by specific physiological milestones. Understanding these boundaries is crucial for clinical management and NEET-PG preparation. **Correct Answer: A. Complete cervical dilatation** The **second stage of labor** is defined as the interval between **full cervical dilatation (10 cm)** and the **expulsion of the fetus**. It represents the phase where the mother begins active pushing (the Valsalva maneuver) to aid fetal descent through the birth canal. **Explanation of Incorrect Options:** * **B. Expulsion of the fetus:** This event marks the **end** of the second stage, not the beginning. * **C. Expulsion of the placenta:** This marks the **end of the third stage** of labor. The third stage begins immediately after the delivery of the fetus and ends with the delivery of the placenta and membranes. * **D. Internal rotation of the fetal head:** This is one of the **cardinal movements of labor** (mechanisms of labor). While it typically occurs during the second stage as the head descends to the pelvic floor, it is a mechanical process rather than a defining boundary of the stage itself. **High-Yield Clinical Pearls for NEET-PG:** * **Duration:** In a primigravida, the second stage typically lasts 2 hours (3 hours with epidural); in a multigravida, it lasts 1 hour (2 hours with epidural). * **The "Fourth Stage":** This is the first hour following placental delivery, critical for monitoring postpartum hemorrhage (PPH). * **Friedman’s Curve:** Traditionally used to track labor progress, though modern WHO Labor Care Guides have updated these parameters.

Question 156: A primigravida is posted for cesarean section due to insufficient pelvis. The pelvic inlet is usually considered to be contracted when:

A. The shortest anteroposterior diameter is less than 10 cm
B. The greatest transverse diameter is less than 12 cm
C. The diagonal conjugate is less than 11.5 cm
D. All of the above (Correct Answer)

Explanation: The pelvic inlet is the first barrier the fetal head must negotiate during labor. It is considered **contracted** when any of its essential diameters are significantly reduced, potentially leading to cephalopelvic disproportion (CPD). ### **Explanation of the Correct Answer (D)** A contracted inlet is defined by specific threshold measurements. If any of the following criteria are met, the inlet is deemed inadequate for a normal-sized fetal head: * **Option A: Shortest Anteroposterior (AP) Diameter < 10 cm.** The Obstetric Conjugate is the shortest AP diameter (measured from the sacral promontory to the inner surface of the symphysis pubis). A measurement below 10 cm is the most common indicator of inlet contraction. * **Option B: Greatest Transverse Diameter < 12 cm.** While AP contraction is more common, a reduction in the widest transverse diameter to less than 12 cm also restricts the available space for engagement. * **Option C: Diagonal Conjugate < 11.5 cm.** This is the only diameter that can be measured clinically during a vaginal examination. Since the Obstetric Conjugate is roughly 1.5–2 cm shorter than the Diagonal Conjugate, a value below 11.5 cm suggests an Obstetric Conjugate of < 10 cm. ### **Clinical Pearls for NEET-PG** * **Most common cause of inlet contraction:** Rickets (historically) or nutritional deficiencies leading to a flat (platypelloid) pelvis. * **Engagement:** In a contracted inlet, the fetal head remains high (floating), leading to an increased risk of **cord prolapse** and **early rupture of membranes**. * **Caldwell-Moloy Classification:** Remember that the **Gynecoid pelvis** is the ideal female pelvis, while the **Android pelvis** is associated with the highest incidence of CPD and deep transverse arrest. * **Rule of Thumb:** If the diagonal conjugate is reachable and measures < 11.5 cm, suspect a contracted inlet and prepare for a possible Cesarean Section.

Question 157: A 30-year-old female presented with eclampsia. After 3 hours of admission, she is complaining of palpitations for which an ECG was performed. Vitals are stable. What is the next best management?

A. DC shock
B. Magnesium sulfate (Correct Answer)
C. Amiodarone
D. Adenosine

Explanation: ***Magnesium sulfate*** - **Torsades de Pointes (TdP)** is polymorphic ventricular tachycardia often seen in eclampsia due to **electrolyte disturbances**, and **IV magnesium sulfate** is the first-line treatment for hemodynamically stable patients. - Magnesium helps **stabilize cardiac membranes** and corrects the underlying **QT prolongation** that predisposes to TdP. *DC shock* - **DC cardioversion** is reserved for **hemodynamically unstable** patients with TdP or ventricular fibrillation. - Since the patient has **stable vitals**, electrical cardioversion is not the immediate first-line treatment. *Amiodarone* - **Prolongs QT interval** and can actually **worsen TdP** by further increasing the risk of polymorphic VT. - Contraindicated in **TdP management** as it may precipitate more arrhythmic episodes. *Adenosine* - Effective for **supraventricular tachycardia (SVT)** by blocking AV nodal conduction temporarily. - **Not effective for ventricular tachycardia** like TdP, as it does not address the underlying ventricular origin of the arrhythmia.

Question 158: Trial of normal labour is contraindicated in:

A. History of previous classical cesarean section (Correct Answer)
B. History of previous cesarean section due to cephalopelvic disproportion (CPD)
C. No history of prior vaginal delivery
D. History of previous cesarean section due to malpresentation

Explanation: **Explanation:** The core concept in determining the safety of a **Trial of Labor After Cesarean (TOLAC)** is the integrity of the uterine scar. **1. Why Option A is Correct:** A **Classical Cesarean Section** involves a vertical incision in the upper muscular segment of the uterus. This area is highly vascular and undergoes significant stretching and contraction during labor. The risk of uterine rupture in a classical scar is approximately **4–9%**, and rupture often occurs catastrophically before or during early labor. Therefore, a history of a classical scar is an absolute contraindication to TOLAC. **2. Why the other options are Incorrect:** * **Option B (Previous CPD):** While CPD was the reason for the first surgery, it is not a permanent contraindication. CPD in a previous pregnancy may have been "relative" (e.g., due to a large baby or malposition). A trial is allowed to see if the current fetus can navigate the pelvis. * **Option C (No prior vaginal delivery):** While a prior vaginal birth increases the success rate of TOLAC, the absence of one is not a contraindication. Many women successfully achieve their first vaginal birth after a previous cesarean. * **Option D (Previous Malpresentation):** If the previous CS was for a non-recurring cause like breech or transverse lie, the success rate for TOLAC is very high (approx. 75–80%). **High-Yield Clinical Pearls for NEET-PG:** * **Ideal Candidate for TOLAC:** Previous one lower segment cesarean section (LSCS) with a non-recurring indication. * **Uterine Rupture Risk:** LSCS scar (0.5–1%) vs. Classical scar (4–9%). * **Contraindications to TOLAC:** Previous classical/T-shaped incision, previous uterine rupture, extensive transfundal uterine surgery (e.g., myomectomy entering the cavity), and medical/obstetric complications precluding vaginal delivery (e.g., placenta previa). * **Wait Time:** An inter-delivery interval of <18 months increases the risk of rupture.

Question 159: Oxytocin infusion should be discontinued if there are more than ----- contractions consistently every 15 minutes?

A. 3
B. 5
C. 7 (Correct Answer)
D. 10

Explanation: **Explanation:** The correct answer is **7 contractions every 15 minutes**. **1. Why 7 is the Correct Answer:** Oxytocin is a potent uterotonic agent used for the induction and augmentation of labor. The primary goal is to achieve an adequate contraction pattern (typically 3–4 contractions in 10 minutes) without causing **uterine tachysystole** or hyperstimulation. According to standard obstetric guidelines (including Williams Obstetrics), oxytocin infusion must be discontinued if uterine activity becomes excessive. Specifically, more than **7 contractions in a 15-minute period** (or more than 5 in 10 minutes) is a clear indication of hyperstimulation. Excessive contractions reduce uteroplacental blood flow during the relaxation phase, leading to fetal hypoxia and potential uterine rupture. **2. Analysis of Incorrect Options:** * **Option A (3):** This is the goal for adequate labor (3 contractions per 10 minutes). Discontinuing at this stage would lead to failed induction. * **Option B (5):** While 5 contractions in **10 minutes** is the definition of tachysystole, the question asks for the threshold over **15 minutes**. 5 in 15 minutes is considered a normal, safe rhythm. * **Option D (10):** This represents extreme hyperstimulation. Waiting for 10 contractions in 15 minutes would likely result in fetal distress or maternal complications. **3. High-Yield Clinical Pearls for NEET-PG:** * **Definition of Tachysystole:** >5 contractions in 10 minutes, averaged over a 30-minute window. * **Half-life of Oxytocin:** Very short (3–5 minutes), which allows for rapid reversal of hyperstimulation once the infusion is stopped. * **Water Intoxication:** A rare but high-yield side effect of high-dose oxytocin due to its structural similarity to ADH (Antidiuretic Hormone). * **Management of Hyperstimulation:** 1. Stop Oxytocin; 2. Left lateral position; 3. Oxygen administration; 4. Consider Tocolytics (e.g., Terbutaline) if fetal distress persists.

Question 160: What is the diameter of the fetal head in a totally deflexed presentation?

A. Suboccipito-frontal
B. Occipito-frontal (Correct Answer)
C. Submento-bregmatic
D. Suboccipito-bregmatic

Explanation: In fetal malpresentations, the diameter of the fetal head engaging the maternal pelvis is determined by the **degree of flexion or extension** of the neck. ### **Explanation of the Correct Answer** In a **totally deflexed (neutral) head**, the fetus is neither flexed nor extended. This is commonly seen in the **Occipito-posterior (OP)** position. The engaging diameter is the **Occipito-frontal (OF)**, which measures approximately **11.5 cm**. It extends from the occipital protuberance to the root of the nose (glabella). Because this diameter is larger than the suboccipito-bregmatic diameter, it often leads to a prolonged labor. ### **Analysis of Incorrect Options** * **A. Suboccipito-frontal (10 cm):** This diameter is seen in a **partially deflexed** head. It extends from the suboccipital region to the anterior end of the anterior fontanelle. * **C. Submento-bregmatic (9.5 cm):** This is the engaging diameter in a **Face presentation** where the head is **completely extended**. * **D. Suboccipito-bregmatic (9.5 cm):** This is the smallest and most ideal diameter, seen when the head is **completely flexed** (Vertex presentation). ### **NEET-PG High-Yield Pearls** * **Vertex (Well-flexed):** Suboccipito-bregmatic (9.5 cm) – Smallest diameter. * **Vertex (Deflexed/OP):** Occipito-frontal (11.5 cm). * **Brow (Partial extension):** Mento-vertical (13.5 cm) – Largest diameter; usually necessitates C-section. * **Face (Complete extension):** Submento-bregmatic (9.5 cm). * **Rule of Thumb:** As the head deflexes, the engaging diameter increases, making vaginal delivery more difficult until complete extension (Face) is reached.

Practice by Chapter

Physiology of Labor

Practice Questions

Stages of Labor and Normal Progression

Practice Questions

Fetal Monitoring Techniques

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Pain Management in Labor

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Induction and Augmentation of Labor

Practice Questions

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

Practice Questions

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