Neonatology — MCQs

A baby is born at 27 weeks of gestation and required mechanical ventilation for 4 weeks and CPAP for 1 week. He was maintained on room air subsequently. Based on the new definition of Bronchopulmonary Dysplasia (BPD), and assuming he remained on room air at 36 weeks post-menstrual age, what is the most appropriate classification of his condition?

Q900

What is the threshold for hyperglycemia in neonates?

Neonatology Indian Medical PG Practice Questions and MCQs

Question 891: In which condition do symptoms improve with crying?

A. Tetralogy of Fallot
B. Choanal atresia (Correct Answer)
C. Bronchial asthma
D. None of the options

Explanation: ***Choanal atresia*** - In **bilateral choanal atresia**, a newborn is unable to breathe through the nose due to a bony or membranous obstruction. Symptoms like **cyanosis** worsen with feeding and improve with crying because crying involves **mouth breathing**, which bypasses the nasal obstruction. - This condition is a **medical emergency** as newborns are obligate nasal breathers, and immediate intervention (e.g., oral airway, surgical repair) is often required. *Tetralogy of Fallot* - This congenital heart defect can lead to **cyanotic spells** (hypercyanotic or "tet" spells), which are characterized by increased cyanosis, tachypnea, and irritability. These spells are often precipitated by activities that increase right-to-left shunting, and **crying can worsen them** rather than improve them due to increased systemic oxygen demand and vascular resistance. - Management often involves positioning (knee-chest) and medications to reduce pulmonary vascular resistance or increase systemic vascular resistance, to alleviate shunting. *Bronchial asthma* - **Crying is a common trigger for asthma attacks** in children, as it can induce bronchoconstriction due to hyperventilation and airway irritation. Symptoms typically worsen with crying, leading to **wheezing, coughing, and shortness of breath**. - Asthma is characterized by **reversible airway obstruction** and airway hyperresponsiveness, and its symptoms do not improve with crying. *None of the options* - This option is incorrect because **choanal atresia** is a condition where symptoms (specifically cyanosis) do improve with crying due to the switch from nasal to mouth breathing.

Question 892: All of the following are features of prematurity in a neonate, except which of the following?

A. Abundant lanugo
B. Thick ear cartilage (Correct Answer)
C. Empty scrotum
D. No creases on sole

Explanation: ***Thick ear cartilage*** - **Thick ear cartilage with well-formed incurving of the pinna** is a feature of a **mature** or **full-term** neonate. - In premature neonates, the ear cartilage is typically **thin, soft, and flexible**, with less developed incurving. *Abundant lanugo* - **Lanugo**, fine soft hair, is typically abundant on the back and shoulders of **premature neonates**. - This hair is often shed by full-term babies before or shortly after birth. *Empty scrotum* - An **empty scrotum** indicates undescended testes, which is common in **premature male neonates**. - Testicular descent typically occurs later in gestation. *No creases on sole* - The absence or scarcity of **creases on the sole of the foot** is characteristic of **premature neonates**. - As gestational age increases, the number and depth of plantar creases increase.

Question 893: What is the APGAR score for a baby that grimaces in response to stimulation?

A. 0
B. 1 (Correct Answer)
C. 2
D. 3

Explanation: ***1*** - A score of **1** is given for **grimace** in response to stimulation, indicating some reflex irritability but not a vigorous cry or sneeze. - This response shows a minimal protective reflex, suggesting the baby is not completely flaccid but also not optimally responsive. - The APGAR scoring for reflex irritability ranges from 0 to 2, with grimacing specifically scoring **1 point**. *0* - A score of **0** for reflex irritability is reserved for **no response** or **complete absence** of reflexes. - This would indicate a severely depressed neurological state, unlike the grimace observed. *2* - A score of **2** for reflex irritability is given for a **vigorous cry**, **sneeze**, **cough**, or **active withdrawal** from stimulation. - A grimace is a less robust response than these, thus not warranting a score of 2. *3* - The APGAR scoring system uses a **0-2 scale** for each of the five components (Appearance, Pulse, Grimace, Activity, Respiration). - The maximum score for any single component is **2**, making 3 an invalid score. - Total APGAR scores range from 0-10, but individual components never exceed 2.

Question 894: What is the standard duration used to define apnea of prematurity?

A. Between 10 and 15 sec
B. 20 sec (Correct Answer)
C. More than 30 sec
D. Less than 10 sec

Explanation: ***20 sec*** - Apnea of prematurity is defined as a cessation of breathing lasting **20 seconds or longer**, or a shorter pause in breathing accompanied by **bradycardia** (heart rate <100 bpm), **cyanosis**, or **pallor**. - This duration is crucial for determining the need for intervention and diagnosis in preterm infants. - The definition is standardized by the **American Academy of Pediatrics (AAP)** and is widely accepted in neonatal care. *Between 10 and 15 sec* - While pauses in breathing of this duration can be observed in preterm infants, they are usually considered **central periodic breathing** and not true apnea of prematurity unless accompanied by desaturation or bradycardia. - These shorter pauses are often considered benign, as significant physiological changes like bradycardia or cyanosis are less likely to occur. *More than 30 sec* - While a breathing cessation of more than 30 seconds certainly qualifies as apnea of prematurity, **20 seconds is the established minimum duration** for diagnosis. - Any apnea lasting longer than 20 seconds signifies a more severe event, indicating a greater risk to the infant. *Less than 10 sec* - Pauses in breathing lasting less than 10 seconds are generally considered **normal physiological variations** in both preterm and full-term infants. - These short pauses do not typically lead to significant oxygen desaturation or bradycardia and are not indicative of apnea of prematurity.

Question 895: Which of the following is NOT a characteristic of caput succedaneum?

A. Crosses the suture line
B. Crosses midline
C. It does not disappear within 2-3 days (Correct Answer)
D. It is a diffuse edematous swelling of the soft tissues of the scalp

Explanation: ***It does not disappear within 2-3 days*** - Caput succedaneum is a benign condition that typically resolves within **2 to 3 days** after birth as the edema is reabsorbed. - Therefore, a characteristic of caput succedaneum is that it *does* disappear relatively quickly, making the statement that it "does not disappear within 2-3 days" incorrect. *Crosses midline* - Caput succedaneum is a **diffuse swelling** that extends across the scalp and is **not limited by anatomical boundaries** like the midline of the skull. - This characteristic helps differentiate it from a **cephalohematoma**, which is typically confined to one side of the head. *Crosses the suture line* - The edema of caput succedaneum is in the **soft tissues superficial to the periosteum**, allowing it to **cross the suture lines** of the skull. - This is a key differentiating feature from a **cephalohematoma**, which is a subperiosteal hemorrhage and therefore confined by suture lines. *It is a diffuse edematous swelling of the soft tissues of the scalp* - This statement accurately describes caput succedaneum as a **collection of serosanguineous fluid** and **edema** in the most superficial layers of the scalp. - It results from pressure on the fetal scalp during labor, leading to **venous congestion** and extravasation of fluid.

Question 896: Which of the following is the most practical method for transporting a newborn while maintaining a warm temperature, especially in resource-limited settings?

A. Kangaroo Mother Care (KMC) (Correct Answer)
B. Transport incubator
C. Insulated box (e.g., Thermacol box)
D. Warm water bag

Explanation: ***Kangaroo Mother Care (KMC)*** - KMC involves continuous **skin-to-skin contact** between the newborn and the caregiver, which is highly effective in maintaining the infant's temperature through direct body warmth transfer. - It is a **low-cost**, easily accessible method, making it particularly practical and sustainable in **resource-limited settings**. - KMC is endorsed by **WHO** as an evidence-based intervention for thermal care of low birth weight and preterm infants. *Transport incubator* - While effective for maintaining temperature, a transport incubator is **expensive**, requires electricity or specialized batteries, and is not readily available in many resource-limited settings. - The use of an incubator requires **trained personnel** for operation and maintenance, making it less practical for widespread use in such environments. *Insulated box (e.g., Thermacol box)* - An insulated box can provide some thermal insulation, but it lacks an **active heating mechanism** and does not provide tactile stimulation or bonding benefits. - The temperature inside can still fluctuate significantly, and it does not allow for **continuous monitoring** of the newborn, increasing the risk of overheating or hypothermia if not managed carefully. *Warm water bag* - A warm water bag can provide localized warmth but carries a significant risk of **burns** if the water is too hot or if the bag leaks. - Its warming effect is also **temporary** and not evenly distributed, making it less reliable for maintaining stable body temperature during prolonged transport.

Question 897: What is the PRIMARY pathophysiological mechanism underlying the most common cause of neonatal hyperbilirubinemia?

A. Inefficient erythropoiesis
B. Immature liver enzyme (Correct Answer)
C. RBC hemolysis
D. Decreased bilirubin excretion

Explanation: ***Immature liver enzyme*** - The most common cause of neonatal hyperbilirubinemia is **physiological jaundice**, and its PRIMARY pathophysiological mechanism is **immature hepatic conjugation** due to deficiency of **UDP-glucuronosyltransferase (UGT1A1)**. - While neonates do produce more bilirubin from RBC breakdown, the **rate-limiting step** is the liver's inability to conjugate unconjugated bilirubin efficiently for excretion. - This immaturity causes accumulation of unconjugated bilirubin, which peaks at **3-5 days of life** and resolves as the enzyme system matures by **7-10 days**. - Key clinical feature: **Unconjugated (indirect) hyperbilirubinemia** in an otherwise healthy term neonate. *RBC hemolysis* - Neonates do have a **shorter RBC lifespan** (70-90 days vs. 120 days in adults) and higher hematocrit, leading to increased bilirubin production (~2-3 times adult rate). - However, this is a **contributory factor**, not the primary mechanism—a normal liver can handle this load easily. - **Pathological hemolysis** (ABO/Rh incompatibility, G6PD deficiency, spherocytosis) causes jaundice through a different mechanism with earlier onset (<24 hours) and more severe hyperbilirubinemia. *Inefficient erythropoiesis* - Ineffective erythropoiesis (abnormal RBC production with intramedullary destruction) is seen in conditions like **thalassemia** and **megaloblastic anemia**. - This can contribute to increased bilirubin load but is not the mechanism in physiological jaundice. - In neonates, erythropoiesis is typically transitioning from fetal to adult hemoglobin but is not pathologically inefficient. *Decreased bilirubin excretion* - Decreased excretion of **conjugated bilirubin** occurs in **cholestatic conditions** (biliary atresia, neonatal hepatitis, choledochal cyst). - This results in **direct (conjugated) hyperbilirubinemia**, not the indirect hyperbilirubinemia seen in physiological jaundice. - While neonates do have relatively decreased enterohepatic circulation clearance, the primary bottleneck is conjugation, not excretion.

Question 898: A 24-day-old neonate presents with projectile vomiting and failure to gain weight. What is the most likely diagnosis?

A. NEC
B. Duodenal atresia
C. Hirschsprung's disease
D. Congenital Hypertrophic Pyloric Stenosis (Correct Answer)

Explanation: ***Congenital Hypertrophic Pyloric Stenosis*** - The classic presentation includes **projectile, non-bilious vomiting** in a neonate around 2-8 weeks old, leading to **failure to thrive**. - An **olive-shaped mass** (hypertrophied pylorus) may be palpable in the epigastrium. *NEC* - **Necrotizing enterocolitis (NEC)** is an inflammatory disease of the intestine, primarily affecting premature infants. - Symptoms typically include **abdominal distension**, bloody stools, and lethargy, rather than projectile vomiting. *Duodenal atresia* - Presents with **bilious vomiting** within the first 24-48 hours of life due to an obstruction below the ampulla of Vater. - An X-ray would show a **"double bubble" sign**, which is not implied by the provided symptoms. *Hirschsprung's disease* - Characterized by **failure to pass meconium** within the first 24-48 hours and chronic constipation. - Vomiting, if present, is usually **bilious** and associated with abdominal distension, not projectile in nature.

Question 899: A baby is born at 27 weeks of gestation and required mechanical ventilation for 4 weeks and CPAP for 1 week. He was maintained on room air subsequently. Based on the new definition of Bronchopulmonary Dysplasia (BPD), and assuming he remained on room air at 36 weeks post-menstrual age, what is the most appropriate classification of his condition?

A. Mild BPD (Correct Answer)
B. Moderate BPD
C. Severe BPD
D. No BPD

Explanation: ***Mild BPD*** - The infant required respiratory support (ventilation and CPAP) for an extended period (5 weeks total, far exceeding the 28-day oxygen requirement for BPD diagnosis). - Being on **room air at 36 weeks post-menstrual age** despite prior prolonged support classifies his condition as mild BPD according to the diagnostic criteria. - For infants born <32 weeks gestation, mild BPD is defined as needing oxygen for ≥28 days but breathing room air at 36 weeks PMA. *Moderate BPD* - Moderate BPD would be diagnosed if the infant still required **less than 30% oxygen (FiO2 0.22-0.29) at 36 weeks post-menstrual age**. - This infant was on room air (FiO2 0.21), indicating less severe lung disease than moderate BPD. *Severe BPD* - Severe BPD involves the ongoing need for **30% or greater oxygen (FiO2 ≥0.30)** and/or positive pressure support (CPAP/ventilator) at 36 weeks post-menstrual age. - This infant did not meet these criteria, as he was on room air without any support. *No BPD* - No BPD would require **less than 28 days of oxygen/respiratory support** during the neonatal period. - This infant required mechanical ventilation for 4 weeks and CPAP for 1 week (total 5 weeks = 35 days), clearly exceeding the 28-day threshold for BPD diagnosis. - Despite being stable on room air at 36 weeks PMA, the prolonged earlier support establishes the diagnosis of BPD (mild severity).

Question 900: What is the threshold for hyperglycemia in neonates?

A. 150 mg/dl (Correct Answer)
B. 180 mg/dl
C. 100 mg/dl
D. 125 mg/dl

Explanation: ***150 mg/dl*** - A blood glucose level greater than **150 mg/dL** is the **standard threshold** most commonly taught and used for defining **hyperglycemia** in neonates. - This value is widely accepted in clinical practice and guides decisions regarding **glucose management** and potential **insulin therapy** in this population. - This threshold is particularly relevant for term and late preterm neonates. *125 mg/dl* - While **125 mg/dL** represents an elevated glucose level and some newer guidelines consider this as a threshold (especially >7 mmol/L), it is **not the standard taught threshold** of 150 mg/dL. - For examination purposes, **150 mg/dL** remains the recognized standard definition. *180 mg/dl* - A blood glucose level of **180 mg/dL** indicates **severe hyperglycemia** rather than the initial threshold for defining hyperglycemia. - While some protocols for extremely preterm infants may use higher cutoffs, this exceeds the standard diagnostic threshold. - Intervention is typically initiated well before reaching this level to prevent complications. *100 mg/dl* - A blood glucose level of **100 mg/dL** in a neonate falls within the **normal range**, not hyperglycemia. - This level is desirable for proper brain development and metabolic function. - Normal neonatal glucose ranges from approximately **40-100 mg/dL** in the first days of life.

Practice by Chapter

Neonatal Resuscitation

Practice Questions

Care of the Normal Newborn

Practice Questions

Prematurity and Low Birth Weight

Practice Questions

Respiratory Distress Syndrome

Practice Questions

Neonatal Jaundice

Practice Questions

Neonatal Sepsis

Practice Questions

Necrotizing Enterocolitis

Practice Questions

Intraventricular Hemorrhage

Practice Questions

Persistent Pulmonary Hypertension

Practice Questions

Perinatal Asphyxia

Practice Questions

Neonatal Seizures

Practice Questions

Congenital Anomalies

Practice Questions

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