Neonatology — MCQs

A large-for-gestational age newborn infant was born 50 hours ago by cesarean section to a 26-year-old primigravida mother with insulin-dependent gestational diabetes. The infant's initial glucose was 25 mg/dL, but after feeding subsequent glucoses have all been above 60 mg/dL. The infant is now diaphoretic and irritable, and seems to have some twitching and tremors of the extremities. What is the most likely cause of this infant's problems?

Q528Easy

Breastfeeding jaundice typically manifests at which point after birth?

Q529Easy

Risk of kernicterus is increased in all except?

Q530Easy

Which organism commonly causes early-onset neonatal septicemia?

Neonatology Indian Medical PG Practice Questions and MCQs

Question 521: Conjugated hyperbilirubinemia in neonates is a feature of _________?

A. Breast milk jaundice
B. Gilbert's syndrome
C. Hypothyroidism
D. Rotor syndrome (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. Rotor syndrome** **Understanding the Concept:** Hyperbilirubinemia is classified into **unconjugated (indirect)** and **conjugated (direct)** based on whether the bilirubin has undergone glucuronidation in the liver. Conjugated hyperbilirubinemia occurs due to defects in the excretion of bilirubin from hepatocytes into the bile canaliculi or due to biliary obstruction. **Rotor syndrome** is a rare, autosomal recessive condition characterized by a defect in the hepatic storage and uptake of conjugated bilirubin (specifically involving OATP1B1 and OATP1B3 transporters). This leads to an asymptomatic increase in **conjugated bilirubin** in the blood. **Analysis of Incorrect Options:** * **A. Breast milk jaundice:** This is a common cause of prolonged **unconjugated** hyperbilirubinemia. It is thought to be caused by substances in breast milk (like beta-glucuronidase) that increase the enterohepatic circulation of bilirubin. * **B. Gilbert’s syndrome:** This is a genetic defect in the promoter region of the UGT1A1 enzyme, leading to reduced conjugation activity. It results in mild, fluctuating **unconjugated** hyperbilirubinemia, often triggered by stress or fasting. * **C. Hypothyroidism:** Congenital hypothyroidism causes delayed maturation of the UGT enzyme and decreased hepatic uptake, leading to prolonged **unconjugated** hyperbilirubinemia. **High-Yield Clinical Pearls for NEET-PG:** * **Conjugated Hyperbilirubinemia** is always pathological in a neonate (defined as direct bilirubin >1 mg/dL if total is <5 mg/dL, or >20% of total). * **Dubin-Johnson vs. Rotor:** Both cause conjugated hyperbilirubinemia. However, Dubin-Johnson features a **black liver** (due to epinephrine metabolite deposition) and normal total urinary coproporphyrin levels (but high Coproporphyrin I), whereas Rotor syndrome has a **normal-appearing liver** and high total urinary coproporphyrin. * **Biliary Atresia** is the most common surgical cause of conjugated jaundice in neonates; early diagnosis (Kasai procedure before 60 days) is critical.

Question 522: A term neonate presents with unconjugated hyperbilirubinemia of 18 mg/dl on the 29th day of life. Which of the following is NOT a common cause of this condition?

A. Breast milk jaundice
B. Neonatal hepatitis (Correct Answer)
C. G-6-PD deficiency
D. Hypothyroidism

Explanation: ### Explanation The core of this question lies in distinguishing between **unconjugated** and **conjugated** hyperbilirubinemia in a neonate presenting with prolonged jaundice (jaundice persisting beyond 14 days in term neonates). **1. Why "Neonatal Hepatitis" is the correct answer:** Neonatal hepatitis is a cause of **conjugated (direct) hyperbilirubinemia**. It involves hepatocellular injury or biliary obstruction, leading to an elevation of conjugated bilirubin. The question specifically asks for causes of **unconjugated** hyperbilirubinemia. Therefore, Neonatal Hepatitis is the outlier. **2. Analysis of Incorrect Options (Causes of Unconjugated Hyperbilirubinemia):** * **Breast Milk Jaundice (Option A):** This is the most common cause of prolonged unconjugated jaundice in an otherwise healthy, thriving infant. It typically peaks in the 2nd–3rd week and can persist for several weeks. * **G-6-PD Deficiency (Option C):** While often associated with early-onset jaundice, G-6-PD deficiency can cause ongoing hemolysis leading to persistent unconjugated hyperbilirubinemia. * **Hypothyroidism (Option D):** Congenital hypothyroidism is a classic "must-rule-out" cause of prolonged unconjugated jaundice. Thyroid hormones are required for the maturation of hepatic glucuronyltransferase activity. **3. Clinical Pearls for NEET-PG:** * **Definition of Prolonged Jaundice:** Jaundice lasting >14 days in term infants and >21 days in preterm infants. * **The "Rule of 20%":** Conjugated hyperbilirubinemia is defined as a direct bilirubin >1 mg/dl (if total is <5 mg/dl) or >20% of the total bilirubin. * **High-Yield Differential:** If a neonate has prolonged jaundice with **pale stools and hepatomegaly**, suspect Biliary Atresia or Neonatal Hepatitis (Conjugated). If the infant is otherwise well, suspect Breast Milk Jaundice or Hypothyroidism (Unconjugated). * **Crigler-Najjar Syndrome:** Another rare but important cause of severe, persistent unconjugated hyperbilirubinemia due to a total or partial deficiency of the enzyme UGT1A1.

Question 523: What is found on the mid-palatine raphe of a young child?

A. Eruption cyst.
B. Bohn's nodule.
C. Epstein pearl. (Correct Answer)
D. All of the above.

Explanation: **Explanation:** The correct answer is **Epstein pearls**. These are small (1–3 mm), firm, white-to-yellowish keratin-filled cysts commonly found in neonates. **1. Why Epstein Pearls are correct:** Epstein pearls are developmental remnants of trapped epithelium during the fusion of the palatal shelves. Their hallmark location is the **mid-palatine raphe** (the junction of the hard and soft palate). They are benign, asymptomatic, and typically resolve spontaneously within a few weeks of life without treatment. **2. Why other options are incorrect:** * **Bohn’s nodules:** While similar in appearance (keratin cysts), these are located on the **buccal or lingual surfaces of the alveolar ridges** (away from the midline) or at the junction of the hard and soft palate. They arise from remnants of minor salivary glands. * **Eruption cysts:** These are bluish, translucent domes found over the **alveolar ridge** specifically where a tooth is about to erupt. They represent a collection of blood or fluid in the follicular space. **3. NEET-PG High-Yield Pearls:** * **Epstein Pearls:** Midline of the palate (Mid-palatine raphe). * **Bohn’s Nodules:** Alveolar ridge (buccal/lingual aspect). * **Dental Lamina Cysts:** Found on the crest of the alveolar ridge (derived from remnants of the dental lamina). * **Management:** For all three (Epstein, Bohn, and Dental Lamina cysts), the management is **reassurance and observation**, as they rupture and disappear spontaneously. No surgical intervention is required.

Question 524: When neonatal meningitis is caused by streptococci, what is the most common causative agent?

A. Streptococcus pyogenes (Group A)
B. Streptococcus agalactiae (Group B) (Correct Answer)
C. Streptococcus sanguis (Viridans)
D. Streptococcus pneumoniae (Serotype B)

Explanation: **Explanation:** **Streptococcus agalactiae (Group B Streptococcus or GBS)** is the most common cause of neonatal meningitis and sepsis worldwide. The underlying medical concept involves the vertical transmission of GBS from the maternal vaginal or rectal flora to the neonate during labor or via ascending infection. Neonatal meningitis is typically classified into early-onset (first 7 days) and late-onset (7–28 days), with GBS being a leading pathogen in both categories. **Analysis of Incorrect Options:** * **Streptococcus pyogenes (Group A):** Primarily causes skin infections (impetigo) and pharyngitis in older children; it is a rare cause of neonatal meningitis. * **Streptococcus sanguis (Viridans group):** These are normal commensals of the oral cavity. While they can cause subacute bacterial endocarditis, they are not primary pathogens for neonatal meningitis. * **Streptococcus pneumoniae:** While a leading cause of meningitis in infants (>3 months) and adults, it is significantly less common than GBS in the immediate neonatal period. **High-Yield Clinical Pearls for NEET-PG:** * **The "Big Three" of Neonatal Meningitis:** 1. *Group B Streptococcus*, 2. *Escherichia coli* (K1 antigen), 3. *Listeria monocytogenes*. * **Empiric Treatment:** The standard regimen is **Ampicillin + Gentamicin** (or Cefotaxime) to cover these three pathogens. * **Prevention:** Intrapartum antibiotic prophylaxis (usually Penicillin G) is administered to GBS-colonized mothers to prevent early-onset disease. * **Late-onset Meningitis:** Often associated with *Staphylococcus aureus* or Coagulase-negative Staphylococci (CONS) in NICU settings.

Question 525: Which of the following is NOT associated with cephalhematoma?

A. Swelling is present at birth (Correct Answer)
B. Usually involves parietal and occipital bone
C. Bleeding is subperiosteal
D. Usually reabsorbed in 2-3 months

Explanation: ### Explanation **Cephalhematoma** is a common birth injury characterized by the accumulation of blood between the skull bone and its overlying periosteum. **1. Why Option A is the Correct Answer (The "NOT" associated feature):** Unlike Caput Succedaneum, a **cephalhematoma is typically NOT present at birth.** The swelling usually appears several hours to a day after delivery as the subperiosteal bleeding occurs slowly. Because the bleeding is **subperiosteal**, it is limited by the periosteal attachments to the suture lines; therefore, the swelling does not cross suture lines. **2. Analysis of Other Options:** * **Option B (Involves parietal/occipital bone):** This is a correct clinical feature. The parietal bone is the most common site, followed by the occipital bone. * **Option C (Subperiosteal bleeding):** This is the defining anatomical characteristic. Because the blood is trapped under the periosteum, it remains localized to a single bone. * **Option D (Reabsorbed in 2-3 months):** This is correct. Most cephalhematomas resolve spontaneously within weeks to months. Occasionally, they may undergo peripheral calcification, giving a "hard" feel to the edges. **3. High-Yield Clinical Pearls for NEET-PG:** * **Caput Succedaneum vs. Cephalhematoma:** Caput is present at birth, involves soft tissue edema, and **crosses** suture lines. Cephalhematoma appears later and **does not cross** suture lines. * **Subgaleal Hemorrhage:** This is the most dangerous "scalp" swelling. It occurs between the aponeurosis and periosteum, can cross sutures, and may lead to massive blood loss and shock. * **Complications:** While usually benign, a large cephalhematoma can lead to **unconjugated hyperbilirubinemia** (jaundice) as the red cells break down. * **Management:** Observation only. Incision and drainage are strictly contraindicated due to the high risk of infection (osteomyelitis).

Question 526: A 7-day-old infant presents with symptoms of neonatal septicemia. What is the most likely cause?

A. Local nursery environment (Correct Answer)
B. Infection through the umbilical cord
C. Exclusively breastfed baby
D. Infection by gastrointestinal tract bacteria

Explanation: **Explanation:** Neonatal sepsis is categorized into **Early-Onset Sepsis (EOS)**, occurring within the first 72 hours of life, and **Late-Onset Sepsis (LOS)**, occurring after 72 hours. This 7-day-old infant falls into the LOS category. **Why Option A is correct:** Late-onset sepsis is primarily caused by microorganisms acquired from the **local nursery environment** or the community (nosocomial or horizontal transmission). In a hospital setting, the environment—including medical equipment, sinks, and the hands of healthcare workers—serves as a reservoir for pathogens like *Coagulase-negative Staphylococci (CONS)*, *Staphylococcus aureus*, and Gram-negative bacilli (e.g., *Klebsiella*). This is the most common source for infants presenting at one week of age. **Why other options are incorrect:** * **Option B:** While the umbilical cord (omphalitis) can be a portal of entry, it is a specific site of infection rather than the primary epidemiological "cause" or source compared to the broader nursery environment. * **Option C:** Exclusive breastfeeding is actually a **protective factor**. Breast milk contains IgA and lactoferrin, which reduce the risk of neonatal infections and necrotizing enterocolitis. * **Option D:** While GI flora can cause sepsis, the initial colonization of the GI tract in LOS is usually determined by the bacteria present in the nursery environment. **NEET-PG High-Yield Pearls:** * **EOS (<72 hrs):** Source is maternal genital tract (Vertical transmission). Most common organism globally: *Group B Streptococcus (GBS)*. * **LOS (>72 hrs):** Source is the environment (Horizontal transmission). Most common organism in India: *Klebsiella pneumoniae*. * **Gold Standard Diagnosis:** Blood culture remains the definitive investigation for neonatal septicemia. * **Most common clinical sign:** Refusal to feed and lethargy ("not doing well").

Question 527: A large-for-gestational age newborn infant was born 50 hours ago by cesarean section to a 26-year-old primigravida mother with insulin-dependent gestational diabetes. The infant's initial glucose was 25 mg/dL, but after feeding subsequent glucoses have all been above 60 mg/dL. The infant is now diaphoretic and irritable, and seems to have some twitching and tremors of the extremities. What is the most likely cause of this infant's problems?

A. Hypernatremia
B. Hypocalcemia (Correct Answer)
C. Hypoglycemia
D. Hyperphosphatemia

Explanation: **Explanation:** The infant in this scenario is an **Infant of a Diabetic Mother (IDM)** presenting with signs of neuromuscular irritability (twitching, tremors, irritability) at **50 hours of life**. **1. Why Hypocalcemia is Correct:** Hypocalcemia is a common metabolic complication in IDMs. It typically presents in two peaks: early (first 24–72 hours) and late. The underlying mechanism involves **maternal hypermagnesemia** (due to maternal diabetes) which crosses the placenta and causes **functional hypoparathyroidism** in the neonate. This leads to transiently low Parathyroid Hormone (PTH) levels, resulting in decreased serum calcium. The timing (50 hours) and symptoms (tremors/jitteriness) are classic for hypocalcemia. **2. Why Incorrect Options are Wrong:** * **Hypoglycemia:** While IDMs are at high risk for hypoglycemia due to fetal hyperinsulinism, it typically occurs within the first **1–6 hours** of life. This infant’s glucose levels have been stable (>60 mg/dL) after initial feeds, making this unlikely. * **Hypernatremia:** This usually results from dehydration or excessive sodium intake, neither of which is suggested here. * **Hyperphosphatemia:** While often associated with hypocalcemia in chronic renal failure or specific endocrine disorders, it is not the primary driver of neonatal jitteriness in an IDM. **Clinical Pearls for NEET-PG:** * **IDM Triad of "Hypos":** Hypoglycemia, Hypocalcemia, and Hypomagnesemia. * **Jitteriness vs. Seizure:** Jitteriness (tremors) in hypocalcemia can be provoked by stimuli and stops with passive flexion of the limb, unlike true seizures. * **Cardiac Link:** IDMs are also at risk for **Hypertrophic Cardiomyopathy** (specifically asymmetric septal hypertrophy) and **Congenital Heart Disease** (most commonly VSD and TGA).

Question 528: Breastfeeding jaundice typically manifests at which point after birth?

A. The 3rd day (Correct Answer)
B. The 3rd week
C. The 3rd month
D. Within 24 hours

Explanation: **Explanation:** **Breastfeeding jaundice** (also known as breastfeeding failure jaundice) is a type of unconjugated hyperbilirubinemia that occurs due to **inadequate milk intake** and relative dehydration. 1. **Why Option A is correct:** Breastfeeding jaundice typically manifests on the **3rd day of life** (early-onset). The underlying mechanism is a lack of sufficient caloric intake, leading to decreased stool frequency and increased **enterohepatic circulation** of bilirubin. As maternal milk production (lactogenesis II) often peaks around day 3, infants who have difficulty latching or infrequent feeding sessions show rising bilirubin levels at this time. 2. **Why other options are incorrect:** * **Option B & C:** These represent late-onset jaundice. **Breast milk jaundice** (distinct from breastfeeding jaundice) typically peaks in the **2nd or 3rd week** and is caused by substances in breast milk (like beta-glucuronidase) that interfere with bilirubin metabolism. * **Option D:** Jaundice within the **first 24 hours** is always considered **pathological**. Common causes include ABO or Rh incompatibility and intrauterine infections (TORCH). **High-Yield Clinical Pearls for NEET-PG:** * **Management:** The primary treatment for breastfeeding jaundice is increasing the frequency of breastfeeding (10–12 times/day) and improving latch; **do not** discontinue breastfeeding. * **Breastfeeding vs. Breast Milk Jaundice:** Remember, "Breastfeeding" (Failure) is **Early** (Day 3–5), while "Breast Milk" (Substance-related) is **Late** (Day 7–14). * **Kramer’s Rule:** Used to clinically estimate bilirubin levels based on the cephalocaudal progression of jaundice.

Question 529: Risk of kernicterus is increased in all except?

A. Low level of serum albumin
B. Prematurity
C. Acidosis
D. High levels of serum albumin (Correct Answer)

Explanation: **Explanation:** The risk of **kernicterus** (bilirubin-induced neurological dysfunction) is primarily determined by the concentration of **free (unbound) unconjugated bilirubin** that can cross the blood-brain barrier. **Why Option D is correct:** Unconjugated bilirubin is hydrophobic and travels in the blood bound to **albumin**. Albumin acts as a protective carrier; as long as bilirubin is bound to it, it cannot enter the brain. **High levels of serum albumin** provide more binding sites, thereby reducing the amount of free bilirubin and **decreasing** the risk of kernicterus. **Why other options are incorrect:** * **Low level of serum albumin (A):** Fewer binding sites lead to an increase in free, unbound bilirubin, raising the risk of neurotoxicity. * **Prematurity (B):** Preterm neonates have an immature blood-brain barrier, lower albumin levels, and a higher incidence of co-morbidities, making them highly susceptible to kernicterus even at lower bilirubin levels. * **Acidosis (C):** Acidosis reduces the binding affinity of albumin for bilirubin. It also increases the permeability of the blood-brain barrier, facilitating the entry of bilirubin into brain tissues. **NEET-PG High-Yield Pearls:** 1. **Drugs displacing bilirubin:** Certain drugs like **Sulfonamides, Ceftriaxone, and Salicylates** compete for albumin binding sites and can precipitate kernicterus. 2. **Target area:** Kernicterus most commonly affects the **Basal Ganglia** (specifically the Globus Pallidus) and the Subthalamic nuclei. 3. **Bilirubin type:** Only **unconjugated (indirect)** bilirubin causes kernicterus; conjugated bilirubin is water-soluble and cannot cross the blood-brain barrier. 4. **Clinical Sign:** The earliest sign of acute bilirubin encephalopathy is often poor feeding and lethargy, progressing to **opisthotonus** (retrocollis).

Question 530: Which organism commonly causes early-onset neonatal septicemia?

A. Streptococcus agalactiae (Correct Answer)
B. Streptococcus bovis
C. Streptococcus pyogenes
D. Streptococcus viridans

Explanation: **Explanation:** **Early-Onset Neonatal Sepsis (EONS)** occurs within the first 72 hours of life and is typically caused by the vertical transmission of pathogens from the maternal genital tract during labor or delivery. **Correct Option (A): Streptococcus agalactiae** Also known as **Group B Streptococcus (GBS)**, this is the most common cause of EONS worldwide. It colonizes the maternal vagina and rectum; during birth, the neonate can aspirate infected amniotic fluid or vaginal secretions, leading to pneumonia, septicemia, or meningitis. In developing countries like India, while GBS remains significant, Gram-negative organisms like *Klebsiella* and *E. coli* are also frequently isolated. **Incorrect Options:** * **B. Streptococcus bovis:** Now reclassified as *S. gallolyticus*, it is a Group D Strep associated with endocarditis and colorectal cancer in adults, not neonatal sepsis. * **C. Streptococcus pyogenes:** Known as Group A Strep (GAS), it causes pharyngitis, skin infections, and rheumatic fever. While it can cause puerperal sepsis in mothers, it is a rare cause of neonatal sepsis. * **D. Streptococcus viridans:** These are normal commensals of the oropharynx. They are low-virulence organisms usually associated with subacute bacterial endocarditis or dental caries. **High-Yield Clinical Pearls for NEET-PG:** * **Definition of EONS:** Onset <72 hours of life (some guidelines use <7 days). * **Top 3 Pathogens (Global):** Group B Streptococcus (GBS), *Escherichia coli*, and *Listeria monocytogenes*. * **Indian Scenario:** *Klebsiella pneumoniae* is often cited as the most common cause of neonatal sepsis in many Indian NICUs. * **Risk Factors:** Prematurity, Prolonged Rupture of Membranes (PROM >18 hours), and maternal fever. * **Drug of Choice:** Empirical treatment is a combination of **Ampicillin and Gentamicin**.

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

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free