Labor and Delivery — MCQs

Labor and Delivery Indian Medical PG Practice Questions and MCQs

Question 1041: The pelvic inlet is usually considered to be contracted if its shortest anteroposterior diameter is less than 10 cm.

A. 10 cm (Correct Answer)
B. 12 cm
C. 14 cm
D. 8 cm

Explanation: ***10 cm*** - A pelvic inlet is clinically defined as **contracted** when its shortest anteroposterior diameter (the **obstetric conjugate**) is **less than 10 cm**. - This is the standard threshold used in obstetric practice to identify inlet contraction that may lead to **cephalopelvic disproportion**. - The normal obstetric conjugate measures approximately **10-11 cm**, so values below 10 cm indicate a contracted pelvis requiring careful assessment and management. *8 cm* - While 8 cm represents a **severely contracted pelvis** with significant risk of obstructed labor, it is not the defining threshold. - This measurement indicates **absolute contraction** where vaginal delivery is extremely difficult or impossible, but the standard definition of contraction begins at less than 10 cm. *12 cm* - A measurement of 12 cm for the obstetric conjugate is considered **normal to adequate**, well above the threshold for contraction. - This diameter would facilitate uncomplicated vaginal birth in most cases and poses no concern for inlet contraction. *14 cm* - An obstetric conjugate of 14 cm represents a **very capacious pelvis**, far exceeding normal measurements. - This measurement would pose no risk of cephalopelvic disproportion and indicates an unusually wide pelvic inlet.

Question 1042: Which nerve is most commonly injured in McRoberts maneuver?

A. Femoral nerve (Correct Answer)
B. Lumbosacral trunk
C. Obturator nerve
D. Pudendal nerve

Explanation: ***Femoral nerve*** - The **McRoberts maneuver** involves hyperflexion of the maternal hips, which can cause significant stretch on the maternal **lumbosacral plexus**. - Specifically, the **femoral nerve** (originating from L2-L4) can be compressed or stretched between the inguinal ligament and the hyperflexed thigh, leading to neuropathy. *Lumbosacral trunk* - While the **lumbosacral trunk** is part of the plexus, direct injury to its main body is less common than specific nerve branches during this maneuver. - The compression or stretch is often more focused on individual nerves passing through the pelvic outlet, such as the femoral nerve. *Obturator nerve* - The **obturator nerve** (L2-L4) passes through the obturator foramen and is less directly susceptible to injury from the hyperflexion of the hips in the McRoberts maneuver compared to the femoral nerve. - Its protected anatomical course makes it less vulnerable to the external forces applied during this maneuver. *Pudendal nerve* - The **pudendal nerve** (S2-S4) is typically associated with injury during vaginal delivery due to compression by the fetal head or forceps, not primarily from the hip hyperflexion in the McRoberts maneuver. - Its location deep within the perineum protects it from the mechanism of injury in the McRoberts maneuver.

Question 1043: If the anal sphincter is injured, what degree of perineal tear does this represent?

A. First degree
B. Third degree (Correct Answer)
C. Fourth degree
D. Second degree

Explanation: ***Third degree*** - A third-degree perineal tear involves the **perineal skin**, **vaginal mucosa**, muscles of the perineal body, and extends to the **anal sphincter complex**. - These tears are categorized further into 3a (less than 50% external anal sphincter involvement), 3b (more than 50% external anal sphincter involvement), and 3c (both external and internal anal sphincter involvement). *First degree* - A first-degree tear involves only the **perineal skin** and/or the **vaginal mucosa**, without involving the deeper perineal muscles or anal sphincter. - These tears are usually **superficial** and often do not require suturing. *Fourth degree* - A fourth-degree tear is the most severe and involves the perineal skin, vaginal mucosa, perineal muscles, **anal sphincter complex**, and extends through the **rectal mucosa**. - This tear penetrates into the **lumen of the rectum**, carrying a higher risk of complications like rectovaginal fistula. *Second degree* - A second-degree tear involves the perineal skin, vaginal mucosa, and the **muscles of the perineal body**, but does not extend to the anal sphincter. - These tears typically require **suturing** to repair the muscle and fascial layers.

Question 1044: Which of the following is not a part of basic essential obstetric care?

A. Blood transfusion (Correct Answer)
B. Administration of parenteral antibiotics
C. Administration of parenteral sedatives for eclampsia
D. Administration of parenteral oxytocic drugs

Explanation: ***Blood transfusion*** - While important in many obstetric emergencies, **blood transfusion** is considered part of **Comprehensive Essential Obstetric Care (CEmOC)**, not basic care. - **Basic Essential Obstetric Care (BEmOC)** focuses on the capability to perform key life-saving interventions but generally lacks the capacity for blood storage or transfusion. *Administration of parenteral antibiotics* - This is a crucial component of **Basic Essential Obstetric Care (BEmOC)**, used to manage infections such as **puerperal sepsis**. - It addresses one of the major causes of maternal mortality. *Administration of parenteral sedatives for eclampsia* - The management of **eclampsia** with parenteral anticonvulsants (e.g., magnesium sulfate) is a fundamental aspect of **Basic Essential Obstetric Care (BEmOC)**. - This intervention prevents and controls seizures, a severe complication of pre-eclampsia. - Note: While the question refers to "sedatives," the correct medical classification is **anticonvulsants**. *Administration of parenteral oxytocic drugs* - The use of **parenteral oxytocic drugs** (e.g., oxytocin) to prevent and treat **postpartum hemorrhage** is a core function of **Basic Essential Obstetric Care (BEmOC)**. - Postpartum hemorrhage is a leading cause of maternal death, and timely oxytocin administration is critical.

Question 1045: Persistent OP position is most common in which pelvis?

A. Android pelvis
B. Gynaecoid pelvis
C. Anthropoid pelvis (Correct Answer)
D. Mixed pelvis

Explanation: ***Anthropoid pelvis*** - The **anthropoid pelvis** has an **oval-shaped inlet** with a **long anteroposterior diameter** and **narrow transverse diameter**. - This pelvic configuration is most commonly associated with **persistent occiput posterior (OP) position** because the narrow transverse diameter limits rotation, while the long AP diameter accommodates the fetal head in the OP or direct OA position. - The fetal head tends to engage and remain in the **direct OP or direct OA position** rather than rotating to the transverse position. - This is the **classic pelvic type associated with persistent OP delivery**. *Android pelvis* - The **android pelvis** has a heart-shaped or triangular inlet, narrow subpubic arch, and prominent ischial spines. - This pelvic type is associated with **difficult labor**, **transverse arrest**, and **deep transverse arrest** of the fetal head. - While it can cause malposition, it is more characteristically associated with **arrest disorders** rather than persistent OP position. *Gynaecoid pelvis* - The **gynaecoid pelvis** is the ideal and most common female pelvic type, with a rounded inlet, wide subpubic arch, and adequate dimensions. - This pelvic shape allows for **optimal fetal head rotation** from OP to OA position during labor. - Persistent OP position is **uncommon** with this pelvic type. *Mixed pelvis* - A **mixed pelvis** exhibits characteristics of more than one fundamental pelvic type. - The likelihood of persistent OP depends on which features predominate, but it is not a specific classic association.

Question 1046: Duration of second stage of labor depends upon -

A. Size of fetus
B. Mother's build
C. Parity (Correct Answer)
D. Lie of fetus

Explanation: ***Parity*** - **Nulliparous** women (first birth) typically have a longer second stage of labor due to less efficient pushing efforts and less compliant soft tissues. - **Multiparous** women (subsequent births) usually experience a shorter second stage because their pelvic floor and birth canal have stretched previously, making descent and expulsion of the fetus easier. *Size of fetus* - While a **macrosomic fetus** could potentially prolong the second stage, it is not the primary determinant compared to parity. - The duration of the second stage is more influenced by the **mother's physiology** and prior birth experience. *Mother's build* - A mother's general build or weight does **not directly determine** the duration of the second stage of labor. - Pelvic structure (pelvimetry) is more relevant than overall build, but even then, parity is a stronger predictive factor. *Lie of fetus* - The **lie of the fetus** (longitudinal, transverse, oblique) is crucial for the initiation and progression of labor, but once the fetus is in a longitudinal lie and engagement occurs, it is not the primary factor determining the *duration* of the second stage itself. - An **unfavorable lie** would likely prevent the onset of effective labor or necessitate a C-section before the second stage is even reached.

Question 1047: Engagement of head in labour means?

A. Smallest horizontal plane of the presenting part has crossed the pelvic outlet
B. Greatest horizontal plane of the presenting part has crossed the pelvic outlet
C. Smallest diameter of the presenting part has crossed the pelvic brim
D. Largest diameter of the presenting part has crossed the pelvic brim (Correct Answer)

Explanation: ***Largest diameter of the presenting part has crossed the pelvic brim*** - **Engagement** is defined as the descent of the widest transverse diameter of the fetal presenting part (typically the **biparietal diameter** for a cephalic presentation) below the **pelvic inlet** or brim. - This signifies that the fetal head has successfully navigated the widest part of the maternal pelvis, indicating that the pelvis is generally adequate for vaginal delivery. *Smallest diameter of the presenting part has crossed the pelvic brim* - This statement is incorrect because engagement refers to the **widest** rather than the smallest diameter negotiating the pelvic inlet. - The smallest diameter crossing the brim would not be a definitive indicator of the head being truly engaged in the pelvis. *Smallest horizontal plane of the presenting part has crossed the pelvic outlet* - This option refers to the **pelvic outlet**, which is a later stage in labor after engagement has already occurred. - Furthermore, referring to the "smallest horizontal plane" is not the standard anatomical description for assessing engagement. *Greatest horizontal plane of the presenting part has crossed the pelvic outlet* - Similar to the previous option, this describes passage through the **pelvic outlet**, not engagement at the pelvic brim. - While "greatest horizontal plane" is closer to the concept of the widest diameter, its location at the outlet makes this definition incorrect for engagement.

Question 1048: Which of the following is an absolute indication for caesarean section?

A. Central placenta previa (Correct Answer)
B. Breech presentation
C. Bad obstetric history
D. Previous caesarean delivery

Explanation: ***Central placenta previa*** - This condition involves the **placenta completely covering the internal cervical os**, blocking the birth canal. - A vaginal delivery would lead to severe, life-threatening **hemorrhage** for both the mother and the fetus, making a C-section mandatory. *Breech presentation* - While many breech presentations are delivered by C-section, it is not an absolute indication. - In certain situations, such as **frank breech** with adequate maternal pelvis and experienced obstetrician, a **vaginal delivery can be attempted** after careful evaluation. *Bad obstetric history* - This refers to a history of adverse pregnancy outcomes, but it is a **relative indication** and not an absolute one for C-section. - The decision for C-section would depend on the **specific nature of the previous adverse outcomes** and current pregnancy complications. *Previous caesarean delivery* - A prior C-section is a very common indication for repeat C-section, but it is **not an absolute indication** for all subsequent deliveries. - Many women with a previous C-section can safely undergo a **trial of labor after cesarean (TOLAC)**, especially if the prior incision was a low transverse uterine incision.

Question 1049: Mediolateral episiotomy is preferred because?

A. Reduces damage to anal sphincter and anal canal (Correct Answer)
B. Less blood loss
C. Easy to suture
D. Easy technique

Explanation: ***Reduces damage to anal sphincter and anal canal*** - The **mediolateral episiotomy** is cut at an angle away from the midline, significantly reducing the risk of extending into the **anal sphincter** and **rectum**. - This angulation helps to avoid severe perineal tears, protecting against **fecal incontinence** and other long-term complications. *Less blood loss* - **Mediolateral episiotomies** often result in more blood loss compared to midline episiotomies due to cutting across more muscle and blood vessels. - The angled incision involves a larger area of vascular tissue, increasing the potential for bleeding. *Easy to suture* - **Mediolateral episiotomies** are generally more complex and difficult to repair than midline episiotomies due to the irregular nature of the angled incision. - Achieving proper anatomical alignment and hemostasis can be challenging. *Easy technique* - While a commonplace procedure, the **mediolateral episiotomy** requires precise angulation and depth to ensure effective tissue release and avoid critical structures. - **Midline episiotomies** are technically simpler to perform due to their straightforward, sagittal incision, though they carry higher risks of severe tears.

Question 1050: Transverse lie is caused by all except which of the following?

A. Prematurity
B. Placenta previa
C. Maternal diabetes (Correct Answer)
D. Multiparity

Explanation: ***Maternal diabetes*** - **Maternal diabetes** is primarily associated with **macrosomia** (larger-than-average fetus) and increased risk of shoulder dystocia, not typically transverse lie. - While it can complicate labor, it does not directly predispose to the fetus lying sideways in the uterus. *Multiparity* - **Multiparity** (multiple prior pregnancies) can lead to **lax abdominal and uterine musculature**, which reduces the integrity of the uterus to maintain fetal orientation. - This laxity allows the fetus more room to move and settle into an abnormal lie, including transverse. *Prematurity* - In **premature deliveries**, the fetus is often smaller and has more space to move within the uterus, increasing the likelihood of an **unstable lie**. - The relative proportions of fetal size to uterine cavity are less constrained in premature infants, facilitating non-longitudinal positions. *Placenta previa* - **Placenta previa** (placenta covering or near the cervix) can physically obstruct the descent of the fetal head into the pelvis, preventing it from engaging in a longitudinal lie. - The placenta's position forces the fetus to lie in a **transverse or oblique orientation** because the lower uterine segment is occupied, preventing proper fetal alignment.

Practice by Chapter

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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