Neonatology — MCQs

Neonatology Indian Medical PG Practice Questions and MCQs

Question 711: A 2-week-old neonate was brought to the hospital with a complaint of non-bilious vomiting. While examining the baby, the physician noted a lump in the right upper quadrant, which showed movement while feeding. What is the likely diagnosis of this child?

A. IHPS (Correct Answer)
B. Duodenal atresia
C. Esophageal atresia
D. Intusussception

Explanation: ***Correct: IHPS (Infantile Hypertrophic Pyloric Stenosis)*** - Classic presentation: **2-8 weeks old neonate** with progressive **non-bilious projectile vomiting** - Hallmark finding: **Palpable olive-shaped mass in right upper quadrant** (hypertrophied pyloric muscle) - **Visible peristaltic waves** from left to right upper abdomen, especially after feeding - Associated with **hypochloremic hypokalemic metabolic alkalosis** - Treatment: Ramstedt pyloromyotomy *Incorrect: Duodenal atresia* - Presents within **first day of life** (not at 2 weeks) - Causes **bilious vomiting** (obstruction distal to ampulla of Vater) - "Double bubble" sign on X-ray - Associated with Down syndrome *Incorrect: Esophageal atresia* - Presents **immediately after birth** with drooling and choking - No palpable abdominal mass - Diagnosed with **inability to pass nasogastric tube** - Often associated with tracheoesophageal fistula (TEF) *Incorrect: Intussusception* - Typical age: **6-36 months** (not neonates) - Presents with **colicky abdominal pain** and "currant jelly" stools - Palpable "sausage-shaped" mass in right upper quadrant - Treatment: Air/hydrostatic reduction

Question 712: Which of the following represents the most severe form of neural tube defect where neural tissue is completely exposed without overlying skin, vertebral arches, or meninges?

A. Meningocele
B. Spina bifida
C. Open Neural tube defect (Correct Answer)
D. Myelomeningocele

Explanation: ***Open Neural tube defect*** - The image displays a severe congenital anomaly where the neural tube has failed to close, leaving the neural tissue completely exposed. This specific presentation is consistent with **rachischisis**, the most severe form of spina bifida. - Characteristic features visible are the complete absence of overlying skin, vertebral arches, and meninges, exposing the flattened, malformed spinal cord (neural placode) along the entire spine. *Meningocele* - A **meningocele** is a less severe defect where a sac containing only meninges and cerebrospinal fluid protrudes through an opening in the spine; the spinal cord itself is not displaced. - This is incorrect as the image clearly shows exposed **neural tissue**, which is not a feature of a simple meningocele. *Spina bifida* - **Spina bifida** is a broad term for a range of defects involving incomplete closure of the spine. It includes mild forms like **spina bifida occulta** and severe forms like myelomeningocele, which are typically localized. - The defect in the image is far more extensive than a typical localized spina bifida, affecting a large portion or the entire spine, making it a severe type of open neural tube defect known as rachischisis. *Myelomeningocele* - In a **myelomeningocele**, both the meninges and the spinal cord protrude through the defect, typically forming a sac on the infant's back. - The image does not show a contained sac but rather a completely open, flattened neural plate, which is characteristic of **rachischisis**, a more severe condition than a typical myelomeningocele.

Question 713: A baby is born with microcephaly, intracerebral calcification and chorioretinitis. Which teratogenic infection is the mother suffering from?

A. CMV
B. Varicella
C. Rubella
D. Toxoplasma (Correct Answer)

Explanation: ***Toxoplasma*** - The triad of **microcephaly**, diffuse **intracerebral calcifications**, and **chorioretinitis** is pathognomonic for symptomatic congenital **Toxoplasmosis**. - This parasitic infection, caused by *Toxoplasma gondii*, is often acquired by the mother through exposure to **cat feces** or ingestion of **undercooked meat** during pregnancy. *CMV* - While CMV causes microcephaly and calcifications (part of the TORCH complex), its calcifications are typically located **periventricularly** rather than diffusely throughout the cortex. - CMV is the leading infectious cause of **sensorineural hearing loss** in children, a major feature often emphasized in its presentation. *Varicella* - Congenital varicella syndrome typically involves specific cutaneous findings, such as **zig-zag skin scarring**, along with **limb hypoplasia**. - Ocular findings in varicella are usually limited to **microphthalmia** and cataracts, not the characteristic chorioretinitis seen here. *Rubella* - Congenital rubella syndrome is defined by defects like **sensorineural hearing loss**, ocular abnormalities (e.g., **cataracts**), and congenital heart defects (**patent ductus arteriosus**). - Although it causes microcephaly, it usually does **not** cause prominent diffuse intracerebral calcifications or chorioretinitis as the primary ophthalmic lesion.

Question 714: When is a blood sample taken to diagnose neonatal hypothyroidism?

A. Immediately from the umbilical cord
B. 72 hours after delivery (Correct Answer)
C. 23-48 hours after delivery
D. 24 hours after delivery

Explanation: ***72 hours after delivery*** - Newborn screening for congenital hypothyroidism is ideally performed **48-72 hours after birth** - This timing avoids false-positive results from the **physiological TSH surge** that occurs in the first 24-48 hours of life - At 72 hours, TSH levels have stabilized and accurately reflect thyroid function - Early detection allows prompt treatment to prevent neurodevelopmental impairment *Immediately from the umbilical cord* - Too early - will capture the physiological TSH surge immediately after birth - Results in high false-positive rate - Not recommended for screening *24 hours after delivery* - Still within the period of physiological TSH elevation - May yield false-positive results - Not optimal timing for screening *23-48 hours after delivery* - The lower end (24-48 hours) is acceptable in some screening programs - However, 48-72 hours is preferred to ensure TSH has normalized from the physiological surge - 72 hours provides more reliable results

Question 715: What is the daily fluid requirement for a 3-day-old baby with a birth weight of 1500 grams?

A. 100-110 ml/kg/day
B. 130-150 ml/kg/day
C. 80-90 ml/kg/day (Correct Answer)
D. 120-130 ml/kg/day

Explanation: ***80-90 ml/kg/day***- This range represents the typical fluid requirement for a very low birth weight (**VLBW**) infant on the second or third day of life (DOL 2-3).- It allows for a safe transition from the restricted fluids (60-80 ml/kg/day) of DOL 1 towards higher maintenance needs, minimizing the risk of conditions like **patent ductus arteriosus (PDA)**.*100-110 ml/kg/day*- This rate is usually required later in the first week (around **DOL 4 to DOL 7**) as the infant's renal function matures and catabolism increases.- Providing this high volume prematurely to a 3-day-old **VLBW** infant increases the risk of **fluid overload** and associated neonatal morbidities.*120-130 ml/kg/day*- This represents a standard high maintenance fluid rate, typically achieved by **DOL 7** or later, especially for infants utilizing **phototherapy**.- It is significantly above the required baseline for a **3-day-old** baby and would lead to potential hyponatremia and **pulmonary edema**.*130-150 ml/kg/day*- This is the usual **full maintenance** or "maximal" fluid requirement often seen after the first week of life (DOL 7+) or in situations requiring high replacement.- Administration of this rate on DOL 3 is strongly discouraged due to the extreme risk of **cardiovascular and pulmonary complications**.

Question 716: What is the most commonly used test for newborn hearing screening?

A. Otoacoustic Emissions (OAE) (Correct Answer)
B. Tympanometry
C. Pure Tone Audiometry (PTA)
D. Brainstem Evoked Response Audiometry (BERA)

Explanation: ***Otoacoustic Emissions (OAE)*** - **Correct Answer** - OAE is the most commonly used screening test because it is **non-invasive, rapid** (takes minutes), and can be performed while the newborn is sleeping or quiet - It assesses the function of the **cochlear outer hair cells**; the presence of an OAE indicates that hearing is likely normal up to the level of the cochlea - Recommended by WHO and AAP for universal newborn hearing screening - High sensitivity and specificity for detecting congenital hearing loss *Brainstem Evoked Response Audiometry (BERA)* - BERA, also called **Auditory Brainstem Response (ABR)**, is an objective test but is typically reserved as a **diagnostic confirmation test** following a 'refer' result on the OAE screen - It measures the electrical activity of the **auditory nerve** and brainstem in response to sound, assessing the entire auditory pathway - More time-consuming and expensive than OAE, making it less practical for universal screening *Pure Tone Audiometry (PTA)* - PTA is the **subjective gold standard test** for hearing assessment, requiring behavioral responses from the patient (raising a hand or pressing a button) - Relies on cooperation and voluntary response, making it only suitable for older children (usually **4 years and above**) and adults - Not feasible for newborn screening due to developmental limitations *Tympanometry* - Tympanometry assesses **middle ear function** (e.g., pressure, compliance, presence of fluid, or eardrum perforation) rather than the overall hearing sensitivity of the inner ear or auditory nerve - Useful for detecting **conductive hearing loss** but is not the primary screening tool for congenital sensorineural hearing loss in newborns - Does not evaluate cochlear or neural function

Question 717: A neonate was brought with a history of frothiness from the mouth and respiratory distress. An X-ray of the neonate is given below. What is the diagnosis?

A. Transient tachypnea of newborn
B. Respiratory distress syndrome
C. Esophageal atresia with tracheo-esophageal fistula (Correct Answer)
D. Congenital diaphragmatic hernia

Explanation: ***Esophageal atresia with tracheo-esophageal fistula*** - The clinical presentation of a neonate with excessive **frothiness from the mouth**, choking, and **respiratory distress** is highly suggestive of this diagnosis. - The X-ray confirms the diagnosis by showing a **coiled orogastric tube** (indicated by the arrow) in the blind-ending upper esophageal pouch. The presence of **gas in the stomach** indicates a communication between the trachea and the distal esophagus (a distal fistula). *Transient tachypnea of newborn* - This is a benign condition caused by delayed clearance of fetal lung fluid, presenting with rapid breathing shortly after birth, usually in term infants delivered by C-section. - The chest X-ray typically shows **perihilar streaking**, **fluid in the fissures**, and mild hyperinflation, not a coiled feeding tube. *Congenital diaphragmatic hernia* - This condition involves the herniation of abdominal contents into the chest, causing severe respiratory distress and a **scaphoid abdomen**. - The chest X-ray would show **bowel loops within the thoracic cavity** and displacement of the mediastinum, which are not seen in this image. *Respiratory distress syndrome* - Primarily seen in premature infants, this is caused by a deficiency of **pulmonary surfactant**. - The characteristic X-ray findings include low lung volumes, a diffuse **ground-glass appearance**, and **air bronchograms**.

Question 718: How much oxygen is given to a term infant with respiratory distress during resuscitation?

A. 21% (Correct Answer)
B. 70%
C. 100%
D. 50%

Explanation: ***Correct: 21% (Room Air)*** - **Current NRP and WHO guidelines** recommend starting resuscitation of **term infants with 21% oxygen (room air)** - Evidence shows room air is **equally effective** as 100% oxygen for initial resuscitation - Reduces **oxidative stress and potential harm** from hyperoxia - Oxygen can be **titrated up** if preductal SpO2 targets are not achieved within expected timeframes - This applies specifically to **term infants (≥37 weeks gestation)** *Incorrect: 70%* - Not a standard concentration used in neonatal resuscitation - Would expose infant to unnecessarily high oxygen levels without clear benefit *Incorrect: 100%* - **Outdated practice** - previously used but no longer recommended for term infants - Associated with increased **oxidative stress** and potential harm - May still be considered for **preterm infants <35 weeks** (start with 21-30% and titrate) *Incorrect: 50%* - Not the recommended starting concentration for term infants - May be used as an **intermediate step** when titrating oxygen if initial room air is insufficient **Key Point:** For term infants, always start with room air (21%) during resuscitation and titrate based on SpO2 targets.

Question 719: A neonate delivered at 36-week gestation develops respiratory distress soon after birth. CXR is as shown. Likely diagnosis?

A. Meconium Aspiration Syndrome
B. Respiratory Distress Syndrome (Correct Answer)
C. Transient Tachypnea of Newborn
D. Neonatal Pneumonia

Explanation: ***Respiratory Distress Syndrome*** - The chest X-ray shows classic features of RDS, including a diffuse **reticulogranular pattern** (ground-glass appearance) and prominent **air bronchograms**, indicative of widespread alveolar atelectasis. - This condition is primarily caused by **surfactant deficiency** in preterm infants (like this 36-week neonate), leading to increased surface tension, alveolar collapse, and respiratory distress shortly after birth. ***Transient Tachypnea of Newborn*** - This is caused by delayed clearance of **fetal lung fluid** and is more common in term infants delivered by Caesarean section. - The chest X-ray typically shows **perihilar streaking**, fluid in the interlobar fissures, and hyperinflation, which are not the primary findings in the provided image. ***Neonatal Pneumonia*** - While it can present with respiratory distress, neonatal pneumonia typically shows **asymmetrical patchy infiltrates**, consolidation, or pleural effusions on chest X-ray. - The diffuse, symmetrical ground-glass appearance seen here is less characteristic of an infectious process like pneumonia, which is often more localized. ***Meconium Aspiration Syndrome*** - This condition occurs in term or post-term infants following aspiration of **meconium-stained amniotic fluid**, which is not mentioned in the history. - The characteristic X-ray findings are coarse, patchy opacities, **hyperinflation**, and potential air-leak syndromes (e.g., pneumothorax), which differ from the image.

Question 720: Which of the following best explains the mechanism of breast milk jaundice?

A. Increased RBC breakdown producing more unconjugated bilirubin
B. Enhanced enterohepatic circulation due to beta-glucuronidase in breast milk deconjugating bilirubin (Correct Answer)
C. Reduced intestinal absorption of bilirubin
D. Hepatocellular injury by breast milk

Explanation: ***Enhanced enterohepatic circulation due to beta-glucuronidase in breast milk deconjugating bilirubin*** - Breast milk contains high levels of **beta-glucuronidase** which deconjugates conjugated bilirubin in the intestine back to unconjugated form, greatly increasing the pool available for reabsorption (enhanced **enterohepatic circulation**). - This is the **PRIMARY mechanism** of breast milk jaundice, leading to prolonged unconjugated hyperbilirubinemia in otherwise healthy breastfed infants. - High concentrations of **non-esterified free fatty acids** and pregnane-3α,20β-diol in breast milk may also inhibit the conjugation enzyme UDP-glucuronyl transferase (secondary mechanism). *Incorrect: Hepatocellular injury by breast milk* - Breast milk jaundice is a benign, physiological process and is **NOT** associated with hepatocellular necrosis or cytotoxic liver injury. - Liver function tests (LFTs) are typically **normal**, differentiating it from pathological liver disease. *Incorrect: Increased RBC breakdown producing more unconjugated bilirubin* - This mechanism is responsible for **hemolytic jaundice** (e.g., ABO incompatibility, G6PD deficiency), implying excessive bilirubin production from red cell destruction. - Breast milk jaundice occurs in neonates with **normal rates of erythrocyte destruction** and hemoglobin turnover. *Incorrect: Reduced intestinal absorption of bilirubin* - The mechanism involves **increased** intestinal absorption of bilirubin due to enhanced enterohepatic circulation. - Beta-glucuronidase breaks down conjugated bilirubin to the absorbable unconjugated form, leading to **excessive reabsorption**, not reduced absorption.

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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