Labor and Delivery — MCQs

Labor and Delivery Indian Medical PG Practice Questions and MCQs

Question 1031: Which layer of the uterus is primarily responsible for its contractile function during childbirth?

A. Perimetrium (outer layer)
B. Functional layer of endometrium
C. Myometrium (Correct Answer)
D. Basal layer of endometrium

Explanation: ***Myometrium*** - This **thickest layer** of the uterine wall is composed primarily of **smooth muscle cells**. - These muscle cells are responsible for generating the forceful **contractions** necessary to expel the fetus during childbirth. *Perimetrium (outer layer)* - The perimetrium is the **outermost serous layer** of the uterus, continuous with the broad ligament. - Its primary function is protective, reducing friction with surrounding organs; it does not contribute to uterine contractions. *Functional layer of endometrium* - This is the **superficial layer** of the endometrium that **sheds during menstruation** if pregnancy does not occur. - Its main roles are to provide a site for **implantation** and nourish an early embryo, not uterine contraction. *Basal layer of endometrium* - The basal layer is the **permanent layer** of the endometrium that remains after menstruation. - Its function is to **regenerate** the functional layer after each menstrual cycle, not to contract during labor.

Question 1032: What degree of perineal tear is indicated by an injury to the rectal mucosa?

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

Explanation: ***Fourth*** - A **fourth-degree perineal tear** involves the perineal skin, vaginal mucosa, perineal muscles, external and internal anal sphincter, and the **rectal mucosa**. - This is the most severe type of tear, extending completely through the **anal sphincter complex** and into the rectum. *First* - A **first-degree tear** only involves the **perineal skin** and/or the **vaginal mucosa**. - It does not extend to the muscles or anal sphincter, let alone the rectal mucosa. *Second* - A **second-degree tear** involves the perineal skin, vaginal mucosa, and the **perineal muscles**, but not the anal sphincter. - While deeper than a first-degree tear, it does not reach the rectal mucosa. *Third* - A **third-degree tear** involves the perineal skin, vaginal mucosa, perineal muscles, and the **anal sphincter complex** (external and/or internal anal sphincter). - It does not extend to the rectal mucosa; if it did, it would be classified as a fourth-degree tear.

Question 1033: Which of the following is NOT a component of Active Management of the Third Stage of Labor?

A. Control cord traction
B. Massage of uterus before control cord traction (Correct Answer)
C. Uterotonic agent within 1 minute of birth
D. None of the options

Explanation: ***Massage of uterus before control cord traction*** - In **Active Management of the Third Stage of Labor (AMTSL)**, uterine massage is typically performed *after* the placenta has been delivered to promote uterine contraction and prevent **postpartum hemorrhage**. - Performing **uterine massage prior to controlled cord traction** is not part of the standard protocol for AMTSL and can be ineffective or even counterproductive if the placenta is not yet separated. *Control cord traction* - **Controlled cord traction** is a key step in AMTSL, performed by gently pulling the umbilical cord while simultaneously providing counter-traction above the pubic symphysis, once signs of placental separation appear. - This maneuver helps to **expel the placenta** more quickly and reduce the duration of the third stage of labor. *Uterotonic agent within 1 minute of birth* - Administering a **uterotonic agent**, such as **oxytocin**, within one minute of birth (or after the anterior shoulder is delivered) is a cornerstone of AMTSL. - **Oxytocin** helps the uterus to contract strongly and continuously, thereby preventing excessive bleeding by compressing blood vessels in the decidua. *None of the options* - This option is incorrect because "Massage of uterus before control cord traction" is indeed **NOT** a component of routine AMTSL. - The other two options—**controlled cord traction** and **administration of a uterotonic agent**—are essential components of AMTSL.

Question 1034: Prevalence of breech presentation at full term is ?

A. 10%
B. 6-7%
C. 3-4% (Correct Answer)
D. 1-2%

Explanation: ***3-4%*** - The prevalence of **breech presentation** at full term (37 weeks or more) is approximately **3-4%** of all singleton pregnancies. - While breech presentation is more common in earlier gestation, most fetuses spontaneously turn to a cephalic presentation by term. *10%* - A prevalence of **10%** for breech presentation is typically observed around **32 weeks of gestation**, not at full term. - This percentage significantly decreases as pregnancy progresses towards term. *6-7%* - A prevalence of **6-7%** for breech presentation is still higher than what is observed at full term. - This range might be encountered in earlier stages of the **third trimester** but not typically at 37 weeks or beyond. *1-2%* - A prevalence of **1-2%** is slightly lower than the generally accepted range for full-term breech presentations. - While some studies might report figures at the lower end, **3-4%** is the more commonly cited and accurate range.

Question 1035: Engaging diameter in face presentation is?

A. Occipitofrontal
B. Suboccipitobregmatic
C. Submentobregmatic (Correct Answer)
D. Mentovertical

Explanation: ***Submentobregmatic*** - In a **face presentation**, the fetal head is completely extended, causing the chin (**mentum**) to present. The engaging diameter is from the **submentum** (below the chin) to the **bregma** (anterior fontanelle). - This diameter measures approximately **9.5 cm** and is the smallest available diameter for engagement in face presentations that are in a **mentum-anterior** position. *Suboccipitobregmatic* - This is the engaging diameter in an **occiput-anterior presentation**, where the head is well-flexed. - It extends from the **subocciput** to the **bregma**, measuring around **9.5 cm**. *Occipitofrontal* - This diameter is involved in a **deflexed head presentation**, such as a **brow presentation**. - It measures about **11.5 cm** and extends from the **occiput** to the **frontal eminences**. *Mentovertical* - This is the engaging diameter for a **brow presentation**, where the head is partially extended. - It is the largest presenting diameter, measuring approximately **13.5 cm**, and typically leads to obstructed labor.

Question 1036: In partograph recommended by WHO, the distance between the alert and action lines is?

A. 1 hour
B. 2 hours
C. 4 hours (Correct Answer)
D. 5 hours

Explanation: ***4 hours*** - The **WHO partograph** uses alert and action lines to detect abnormal labor progression, especially in low-resource settings. - The **4-hour gap** between the alert and action lines provides time for health workers to intervene appropriately before complications become severe. *1 hour* - A 1-hour interval is too short in the context of labor progression, as true deviations often take longer to manifest. - This duration would lead to **premature interventions** and increased anxiety without clinical justification. *2 hours* - While seemingly a practical interval, 2 hours is still considered too short for optimal decision-making regarding labor arrest. - Many physiological variations in labor can occur within 2 hours that do not necessarily indicate a need for intervention. *5 hours* - A 5-hour interval between the alert and action lines would be too long, potentially leading to **delayed interventions** in cases of actual labor dystocia. - This delay could increase the risk of adverse maternal and fetal outcomes, such as **prolonged labor**, **infection**, or **fetal distress**.

Question 1037: The prostaglandin most commonly used at term for induction of labor is?

A. PGI2
B. PGE1
C. PGE2 (Correct Answer)
D. PGF2a

Explanation: ***PGE2*** - **Dinoprostone**, a synthetic form of **PGE2**, is widely used for **cervical ripening** and **labor induction** at term. - It softens and dilates the cervix, making it more favorable for the onset of uterine contractions. *PGI2* - Also known as **prostacyclin**, **PGI2** primarily acts as a **vasodilator** and **inhibitor of platelet aggregation**. - It is not commonly used for labor induction due to its different physiological effects. *PGE1* - **Misoprostol**, a synthetic **PGE1** analog, is also used for labor induction, but **PGE2** (dinoprostone) is generally considered the most commonly used prostaglandin at term for this purpose in many clinical settings. - **PGE1** can be associated with a higher risk of uterine hyperstimulation compared to PGE2. *PGF2a* - **PGF2a** (e.g., carboprost) is primarily used to manage **postpartum hemorrhage** due to its potent **uterotonic effects**. - While it causes uterine contractions, it is not the primary prostaglandin used for routine induction of labor at term.

Question 1038: What is the normal uterine blood flow at term?

A. 50-75 ml/min
B. 150-200 ml/min
C. 350-400 ml/min
D. 500-700 ml/min (Correct Answer)

Explanation: ***500-700 ml/min*** - At term, the uterus receives a substantial blood supply to meet the demands of the **growing fetus** and **placenta**. - This flow represents approximately **10-15% of the total cardiac output** in pregnant women. *50-75 ml/min* - This value is significantly **too low** for uterine blood flow at term. - Such a low flow would be insufficient to sustain fetal growth and development, leading to **fetal compromise**. *150-200 ml/min* - While an increase from non-pregnant levels, this value is still **below the normal range** for a full-term pregnancy. - It would not adequately perfuse the **placental bed** and transfer necessary nutrients and oxygen. *350-400 ml/min* - This range represents a considerable increase but is still somewhat **lower than the typical uterine blood flow at term**. - Uterine blood flow continues to increase throughout pregnancy, peaking in the **third trimester**.

Question 1039: Which of the following represents the shortest transverse diameter of the fetal skull?

A. Biparietal diameter (BPD)
B. Bimastoid diameter (Correct Answer)
C. Bitemporal diameter
D. Suboccipitobregmatic diameter

Explanation: ***Bimastoid diameter*** - The **bimastoid diameter** is the shortest transverse diameter of the fetal skull, measuring approximately **7.5 cm** - It is the distance between the tips of the **mastoid processes** and is crucial for understanding the fetal head's fit through the maternal pelvis *Biparietal diameter (BPD)* - The biparietal diameter measures the distance between the two parietal eminences, typically around **9.5 cm** - It is a commonly used measurement in ultrasound to assess fetal growth and gestational age - This is a larger transverse diameter than the bimastoid *Bitemporal diameter* - The bitemporal diameter is measured between the furthest points on the coronal sutures, typically around **8.0 cm** - It is slightly larger than the bimastoid diameter but still considered a relatively narrow transverse measurement *Suboccipitobregmatic diameter* - The suboccipitobregmatic diameter is an **anteroposterior diameter**, not a transverse one, measuring from beneath the occipital bone to the center of the anterior fontanelle (bregma) - This diameter is approximately **9.5 cm** and is the optimal engaging diameter for vaginal birth when the head is well-flexed - This is not a transverse diameter and therefore cannot be the answer

Question 1040: Cord prolapse is most likely with -

A. Footling breech (Correct Answer)
B. Oligohydramnios
C. Vertex presentation with engaged head
D. Transverse lie

Explanation: ***Footling breech*** - **Footling breech** (one or both feet presenting) is the presentation with the **highest risk** of umbilical cord prolapse, with rates as high as **10-20%**. - The small, irregular presenting part (feet) **does not fill the pelvic inlet adequately**, leaving significant space for the umbilical cord to slip past, especially during rupture of membranes. - This is a **classic obstetric emergency** requiring immediate cesarean delivery when cord prolapse occurs. *Transverse lie* - **Transverse lie** also carries a significantly elevated risk of cord prolapse because the shoulder or arm presents, with **no presenting part engaging the pelvis**. - However, transverse lie is usually **identified before labor** and managed with planned cesarean section, often with **controlled membrane rupture**, which may reduce the actual incidence compared to footling breech where spontaneous rupture can occur. *Vertex presentation with engaged head* - An **engaged vertex** presentation provides excellent protection against cord prolapse because the fetal head **fills the pelvic inlet**, effectively blocking the cord from descending. - This is the **lowest risk** presentation for cord prolapse. *Oligohydramnios* - **Oligohydramnios** (reduced amniotic fluid) is **NOT** a recognized risk factor for cord prolapse. - In fact, reduced fluid volume may limit cord mobility. The related condition **polyhydramnios** (excessive fluid) is associated with increased cord prolapse risk due to increased cord mobility and space.

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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