Neonatology Practice Questions

Q: A baby is said to be small for gestational age if its weight is below which percentile?

10th. **Explanation:** **1. Understanding the Correct Answer (Option B):** In neonatology, the definition of **Small for Gestational Age (SGA)** is based on population-specific growth charts (such as Lubchenco or Fenton charts). A neonate is classified as SGA if their birth weight is **below the 10th percentile** for their specific gestational age and sex. This definition identifies infants who have failed to reach their growth potential in utero, often due to constitutional factors or intrauterine growth restriction (IUGR). **2. Analysis of Incorrect Options:** * **Option A (5th Percentile):** While some specific clinical studies use the 3rd or 5th percentile to identify "severe" growth restriction, the standard international and WHO consensus for the definition of SGA remains the 10th percentile. * **Option C (25th Percentile):** This is within the normal range. Infants between the 10th and 90th percentiles are classified as **Appropriate for Gestational Age (AGA)**. * **Option D (50th Percentile):** This represents the median weight for a given gestational age. **3. High-Yield Clinical Pearls for NEET-PG:** * **SGA vs. IUGR:** SGA is a descriptive term based on birth weight (static), whereas IUGR refers to a dynamic process of reduced growth velocity documented in utero via ultrasound. * **Large for Gestational Age (LGA):** Defined as birth weight **>90th percentile**. * **Low Birth Weight (LBW):** Defined by absolute weight (**<2500g**) regardless of gestational age. * **Common Complications in SGA:** Hypothermia, Hypoglycemia (due to low glycogen stores), Polycythemia (due to fetal hypoxia), and Hypocalcemia. * **Ponderal Index:** Used to differentiate between Symmetrical (Type I) and Asymmetrical (Type II) growth restriction.

Q: What is the condition affecting this newborn with facial dysmorphisms and the features shown below?

Edward's syndrome. ***Edward's syndrome*** - Characterized by **prominent occiput**, **micrognathia**, **low-set ears**, and **overlapping fingers** (index finger over 3rd and 4th fingers), all consistent with **Trisomy 18**. - Additional features include **rocker-bottom feet** and severe **growth restriction**, leading to high neonatal mortality. *Turner's syndrome* - Affects only **females** with **45,X karyotype** and presents with **webbed neck**, **shield chest**, and **lymphedema**. - Does not cause the specific facial dysmorphisms or **overlapping finger pattern** seen in Edward's syndrome. *Alagille syndrome* - Primarily involves **liver dysfunction** with **bile duct paucity** leading to **cholestasis** and **jaundice**. - Facial features include **broad forehead** and **pointed chin**, but lacks the **overlapping fingers** and **rocker-bottom feet**. *Williams syndrome* - Features **elfin-like facies** with **broad forehead**, **stellate iris pattern**, and **supravalvular aortic stenosis**. - Associated with **hypercalcemia** and **developmental delays**, but does not present with **overlapping fingers** or **micrognathia**.

Q: What are the FDA indications for inhaled nitric oxide?

Pulmonary hypertension in a newborn. **Explanation:** Inhaled Nitric Oxide (iNO) is a potent, selective pulmonary vasodilator. It works by increasing intracellular cGMP levels in vascular smooth muscle, leading to relaxation. Because it is inhaled, it specifically targets ventilated alveoli, improving ventilation-perfusion (V/Q) matching without causing systemic hypotension. **Why Option B is Correct:** The FDA has approved iNO specifically for the treatment of **Persistent Pulmonary Hypertension of the Newborn (PPHN)** in term and near-term neonates (>34 weeks gestation) who have hypoxic respiratory failure. It reduces the need for Extracorporeal Membrane Oxygenation (ECMO) by decreasing pulmonary artery pressure and improving oxygenation. **Why Other Options are Incorrect:** * **Option A (Malignant Hypertension):** This is a systemic hypertensive emergency. iNO is rapidly inactivated by hemoglobin when it enters the bloodstream, meaning it has **no systemic effect** and cannot treat systemic hypertension. * **Option C (Cyanotic Congenital Heart Disease):** iNO is generally not the primary FDA-indicated treatment here. In fact, in ductal-dependent lesions (like Hypoplastic Left Heart Syndrome), iNO can be dangerous as it may decrease pulmonary vascular resistance too much, leading to pulmonary over-circulation and systemic steal. **High-Yield Clinical Pearls for NEET-PG:** * **Starting Dose:** Usually 20 ppm (parts per million). * **Monitoring:** Always monitor for **Methemoglobinemia** and Nitrogen Dioxide ($NO_2$) levels during therapy. * **Rebound Effect:** Abrupt withdrawal can cause "rebound pulmonary hypertension"; therefore, iNO must be weaned gradually. * **Contraindication:** It is contraindicated in neonates known to be dependent on **right-to-left shunts** (e.g., severe left-sided obstructive lesions).

Q: Which of the following does not establish a diagnosis of congenital Cytomegalovirus (CMV) infection in a neonate?

IgG CMV antibodies in blood. To establish a diagnosis of **congenital Cytomegalovirus (CMV)** infection, the virus or its components must be identified within the **first 3 weeks of life**. ### **Why Option B is the Correct Answer** **IgG CMV antibodies** in a neonate’s blood do not confirm congenital infection because IgG antibodies cross the placenta from the mother to the fetus (passive immunity). Therefore, a positive IgG test in a newborn may simply reflect maternal past infection rather than an active fetal infection. To diagnose congenital CMV via serology, one would need to detect **CMV-specific IgM**, which does not cross the placenta. ### **Analysis of Incorrect Options** * **A. Urine culture:** This was traditionally the "gold standard." CMV is shed in high titers in the urine of infected neonates. * **C. Intranuclear inclusion bodies:** Histopathological identification of characteristic **"Owl’s eye" inclusion bodies** in tissues (like hepatocytes or renal tubular cells) is pathognomonic for CMV. * **D. PCR for viral DNA:** This is the current preferred diagnostic method due to its high sensitivity and rapid results. It can be performed on blood, urine, or saliva. ### **NEET-PG High-Yield Pearls** * **Timing is Critical:** Testing must be done within **21 days of birth**. Detection after 3 weeks may represent *acquired* (perinatal) infection rather than *congenital*. * **Most Common Cause:** CMV is the most common cause of **congenital sensorineural hearing loss (SNHL)** and non-hereditary mental retardation. * **Classic Triad:** Periventricular calcifications, microcephaly, and SNHL. * **Treatment:** Intravenous **Ganciclovir** or oral **Valganciclovir** is indicated for symptomatic neonates to reduce the severity of hearing loss and developmental delay.

Q: Extremely low birth weight (ELBW) child is defined as?

less than 1000 gm. **Explanation:** The classification of birth weight is a fundamental concept in neonatology, used to predict neonatal morbidity and mortality. The correct answer is **D (less than 1000 gm)**. **1. Why Option D is Correct:** According to the World Health Organization (WHO) and the American Academy of Pediatrics (AAP), an **Extremely Low Birth Weight (ELBW)** infant is defined as a neonate born with a birth weight of **less than 1000 grams** (typically regardless of gestational age). These infants are at the highest risk for complications like Respiratory Distress Syndrome (RDS), Intraventricular Hemorrhage (IVH), and Necrotizing Enterocolitis (NEC). **2. Analysis of Incorrect Options:** * **Option A (<2500 gm):** This defines **Low Birth Weight (LBW)**. It is the most common category and includes both preterm infants and small-for-gestational-age (SGA) infants. * **Option B (<2000 gm):** There is no specific WHO nomenclature for this cutoff; however, in some clinical settings, it is used as a threshold for specialized nursery care. * **Option C ( 4000 gm (or >4500 gm in some guidelines), often associated with maternal diabetes. * **Ponderal Index:** Used to differentiate between symmetrical and asymmetrical IUGR. Formula: $[Weight (g) \times 100] / [Length (cm)]^3$. * **Survival:** The limit of viability is currently considered to be around 22–24 weeks of gestation or a weight of approximately 500g.

Q: Which of the following is NOT a feature of acute bilirubin encephalopathy?

Exaggerated Moro reflex. **Explanation:** Acute Bilirubin Encephalopathy (ABE) refers to the acute clinical manifestations of bilirubin toxicity in the neonatal brain. The correct answer is **Exaggerated Moro reflex** because, in the early and intermediate phases of ABE, the Moro reflex is typically **depressed or absent**, not exaggerated. **Analysis of Options:** * **A. Lethargy:** This is a hallmark of the **Early Phase** of ABE. Infants typically present with poor feeding, hypotonia, and a decreased level of consciousness (lethargy). * **B. Opisthotonus:** This occurs during the **Intermediate and Advanced Phases**. As toxicity progresses, hypertonia of the extensor muscles leads to retrocollis (neck arching) and opisthotonus (back arching). * **D. Choreoathetosis:** This is a classic feature of **Chronic Bilirubin Encephalopathy (Kernicterus)**. While ABE refers to the acute stage, the question asks for features of the encephalopathy process; choreoathetosis represents the permanent extrapyramidal damage to the basal ganglia. * **C. Exaggerated Moro reflex (Correct):** In ABE, the Moro reflex is characteristically **depressed**. An exaggerated Moro reflex is more commonly associated with Neonatal Abstinence Syndrome or early Hypoxic-Ischemic Encephalopathy (Stage 1). **NEET-PG High-Yield Pearls:** 1. **Kernicterus Triad:** Choreoathetoid cerebral palsy, sensorineural hearing loss (SNHL), and upward gaze palsy. 2. **Brain MRI:** The most common finding in the acute phase is increased T1 signal intensity in the **Globus Pallidus**. 3. **Phases of ABE:** * *Phase 1 (Early):* Hypotonia, lethargy, poor suck, depressed Moro. * *Phase 2 (Intermediate):* Hypertonia (opisthotonus), high-pitched cry, fever. * *Phase 3 (Advanced):* Pronounced opisthotonus, seizures, coma, death.

Q: A baby is born with meconium-stained liquor. All of the following are taken into account in terming a baby 'vigorous' EXCEPT:

Colour. In the management of a neonate born through **Meconium-Stained Amniotic Fluid (MSAF)**, the clinical decision-making process depends on whether the baby is "vigorous" or "non-vigorous." ### **Why "Colour" is the Correct Answer** According to the **Neonatal Resuscitation Program (NRP)** guidelines, the definition of a **vigorous** infant is based on three specific clinical parameters: 1. **Strong respiratory effort** (crying or regular breathing) 2. **Good muscle tone** (active movement or flexed extremities) 3. **Heart rate > 100 beats per minute** **Colour** is excluded from this definition because peripheral cyanosis (acrocyanosis) is a physiological finding in the first few minutes of life and is not a reliable indicator of the need for immediate tracheal suctioning or resuscitation in the context of meconium. ### **Analysis of Incorrect Options** * **Tone (Option A):** A vigorous baby must have good muscle tone. Limp or floppy extremities indicate a non-vigorous state. * **Heart Rate (Option C):** A heart rate of >100 bpm is a core requirement for being termed vigorous. * **Respiration (Option D):** Strong respiratory efforts or a loud cry are essential criteria. ### **Clinical Pearls for NEET-PG** * **Current Protocol:** Routine endotracheal suctioning for non-vigorous infants is **no longer recommended** by the latest NRP guidelines. Initial steps (warming, drying, stimulating) should be performed first. * **Suctioning:** If the baby is non-vigorous and has poor respiratory effort, the priority is **Positive Pressure Ventilation (PPV)**. Direct laryngoscopy and tracheal suctioning are only considered if the airway is obstructed. * **Apgar vs. Vigorous Criteria:** Do not confuse these. While "Colour" is a component of the **APGAR score**, it is specifically omitted from the "Vigorous" criteria used for MSAF management.

Q: A term infant has initial Apgar scores of 8 and 10 at 1 and 5 minutes. On auscultation of the chest, a heart murmur is audible. There is hepatosplenomegaly. Cataracts of the crystalline lens are noted. The infant is at the 30th percentile for height and weight. Echocardiography shows a patent ductus arteriosus. Which of the following events is the most likely risk factor for the findings in this infant?

Congenital rubella infection. ### Explanation The clinical presentation of **cataracts**, **Patent Ductus Arteriosus (PDA)**, and **hepatosplenomegaly** in a term infant is the classic triad of **Congenital Rubella Syndrome (CRS)**. **1. Why Option A is Correct:** CRS occurs due to maternal infection with the Rubella virus (a Togavirus) during the first trimester. The virus is teratogenic and leads to: * **Ocular defects:** "Pearly white" nuclear cataracts (most common) and glaucoma. * **Cardiac defects:** PDA (most common) and peripheral pulmonary artery stenosis. * **Auditory defects:** Sensorineural hearing loss (the most common overall finding). * **Systemic signs:** Hepatosplenomegaly, jaundice, and "Blueberry muffin" spots (extramedullary hematopoiesis). **2. Why Incorrect Options are Wrong:** * **B. Dietary folate deficiency:** Primarily associated with **Neural Tube Defects** (e.g., spina bifida, anencephaly), not cataracts or PDA. * **C. Dispermy at conception:** This leads to **Triploidy** (69 chromosomes), which usually results in spontaneous abortion or severe multi-organ anomalies and growth restriction, but does not specifically present with this classic triad. * **D. Erythroblastosis fetalis:** Caused by Rh/ABO incompatibility. It presents with severe anemia, hydrops fetalis, and hepatosplenomegaly due to hemolysis, but it does not cause congenital cataracts or structural heart defects like PDA. **3. High-Yield Clinical Pearls for NEET-PG:** * **Gregg’s Triad:** Cataracts, Deafness, and Cardiac defects (PDA). * **Timing:** The risk of malformation is highest (up to 80%) if the mother is infected within the first **12 weeks** of gestation. * **Diagnosis:** Detection of **Rubella-specific IgM** in the cord blood or infant sera. * **Prevention:** Vaccination with the **MMR vaccine** (Live attenuated). Note: MMR is contraindicated during pregnancy; women should avoid pregnancy for 1 month after vaccination.

Question 1

A baby is said to be small for gestational age if its weight is below which percentile?

Accepted Answer

10th

Answer

5th

Answer

25th

Answer

50th

Question 2

What is the condition affecting this newborn with facial dysmorphisms and the features shown below?

Accepted Answer

Edward's syndrome

Answer

Turner's syndrome

Answer

Alagille syndrome

Answer

Williams syndrome

Question 3

What are the FDA indications for inhaled nitric oxide?

Accepted Answer

Pulmonary hypertension in a newborn

Answer

Malignant hypertension

Answer

Cyanotic congenital heart disease

Answer

None of the above

Question 4

Which of the following does not establish a diagnosis of congenital Cytomegalovirus (CMV) infection in a neonate?

Accepted Answer

IgG CMV antibodies in blood

Answer

Urine culture for CMV

Answer

Intranuclear inclusion bodies in hepatocytes

Answer

CMV viral DNA in blood by polymerase chain reaction

Question 5

Extremely low birth weight (ELBW) child is defined as?

Accepted Answer

less than 1000 gm

Answer

less than 2500 gm

Answer

less than 2000 gm

Answer

less than 1500 gm

Question 6

A newborn infant presents with excessive frothing and choking upon attempted feeding, despite a normal APGAR score at birth. What is the investigation of choice?

Accepted Answer

X-ray chest and abdomen with a red rubber catheter passed per orally into the esophagus

Answer

Esophagoscopy

Answer

Bronchoscopy

Answer

MRI chest

Question 7

Which of the following is NOT a feature of acute bilirubin encephalopathy?

Accepted Answer

Exaggerated Moro reflex

Answer

Lethargy

Answer

Opisthotonus

Answer

Choreoathetosis

Question 8

A baby is born with meconium-stained liquor. All of the following are taken into account in terming a baby 'vigorous' EXCEPT:

Accepted Answer

Colour

Answer

Tone

Answer

Heart Rate

Answer

Respiration

Question 9

A child presented with severe respiratory distress two days after birth. On examination, he was observed to have a scaphoid abdomen and decreased breath sounds on the left side. He was managed by prompt endotracheal intubation. After ET tube placement, the maximal cardiac impulse shifted further to the right side. What should be the next step in management?

Accepted Answer

Remove tube and reattempt intubation

Answer

Confirm the position of the endotracheal tube by chest X-ray

Answer

Nasogastric tube insertion and decompress the bowel

Answer

Chest X-ray to confirm diagnosis

Question 10

A term infant has initial Apgar scores of 8 and 10 at 1 and 5 minutes. On auscultation of the chest, a heart murmur is audible. There is hepatosplenomegaly. Cataracts of the crystalline lens are noted. The infant is at the 30th percentile for height and weight. Echocardiography shows a patent ductus arteriosus. Which of the following events is the most likely risk factor for the findings in this infant?

Accepted Answer

Congenital rubella infection

Answer

Dietary folate deficiency

Answer

Dispermy at conception

Answer

Erythroblastosis fetalis

Neonatology — MCQs

Neonatology — MCQs

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