Neonatology Practice Questions

Q: For a neonate at 48 hours of birth with a history of non-passage of meconium, what is the next step in evaluation?

Lower GI study. **Explanation:** The failure to pass meconium within the first 24–48 hours of life is a clinical red flag, most commonly associated with **Hirschsprung Disease (HD)** or **Meconium Ileus (MI)**. **Why Lower GI Study is the Correct Next Step:** A **Contrast Enema (Lower GI study)** is the initial diagnostic imaging of choice. It serves two critical purposes: 1. **Diagnostic:** It helps differentiate between HD (showing a transition zone with a narrow distal segment and dilated proximal colon) and MI (showing a microcolon with pellet-like meconium). 2. **Therapeutic:** In cases of Meconium Ileus, a gastrografin enema can help dissolve and flush out the inspissated meconium. **Analysis of Incorrect Options:** * **A & B (Sweat Chloride & CFTR Analysis):** While Meconium Ileus is the earliest manifestation of Cystic Fibrosis (CF), these tests are not the *immediate* next step. Sweat chloride is often unreliable in the first two weeks of life due to low sweat rates, and genetic analysis is a confirmatory, not an initial, step. * **D (Manometry):** Anorectal manometry is used to look for the absence of the recto-anal inhibitory reflex (RAIR) in Hirschsprung Disease. However, it is technically difficult to perform and interpret in neonates and is usually reserved for older children or as a secondary investigation. **High-Yield Clinical Pearls for NEET-PG:** * **Normal Physiology:** 95% of full-term neonates pass meconium within 24 hours; 99% within 48 hours. * **Gold Standard:** Rectal Suction Biopsy is the gold standard for diagnosing Hirschsprung Disease (showing absence of ganglion cells and hypertrophied nerve bundles). * **X-ray Finding:** "Soap bubble appearance" (Neuhauser’s sign) in the right iliac fossa is characteristic of Meconium Ileus.

Q: Low birth weight baby is defined as one whose birth weight is:

Less than 2500 g. **Explanation:** The classification of birth weight is a fundamental concept in neonatology, standardized by the World Health Organization (WHO) to identify infants at higher risk for morbidity and mortality. **1. Why Option C is Correct:** A **Low Birth Weight (LBW)** baby is defined as any neonate with a birth weight of **less than 2500 grams (up to and including 2499 g)**, regardless of the gestational age. This threshold is clinically significant because babies below this weight have significantly higher risks of hypothermia, hypoglycemia, infection, and developmental delays. **2. Why Other Options are Incorrect:** * **Option A (<1800 g):** This does not correspond to a standard WHO category. However, babies below 1500 g are classified as **Very Low Birth Weight (VLBW)**. * **Option B (<2000 g):** While these infants require specialized care, this is not the formal cutoff for LBW. * **Option D (<3000 g):** The average birth weight for a healthy Indian neonate is approximately 2.7–2.9 kg. A weight of 2500–3000 g is considered within the normal range, though it may be on the lower side of the distribution. **3. High-Yield Clinical Pearls for NEET-PG:** * **VLBW (Very Low Birth Weight):** 4000 grams (often associated with maternal diabetes). * **Ponderal Index:** Used to differentiate between symmetrical and asymmetrical IUGR. * **Important:** LBW can be due to either **prematurity** (born before 37 weeks) or **Intrauterine Growth Restriction (IUGR)**. In India, the most common cause of LBW is IUGR due to maternal malnutrition and anemia.

Q: Which type of neonatal seizure has the best prognosis?

Focal. **Explanation:** The prognosis of neonatal seizures is primarily determined by the underlying etiology and the specific seizure semiology. **1. Why Focal Seizures are the Correct Answer:** Focal seizures (specifically focal clonic seizures) are associated with the best neurological prognosis. This is because they are often localized and frequently associated with focal brain lesions or transient metabolic disturbances that may not involve global encephalopathy. In the neonatal period, focal clonic seizures have a high correlation with localized pathology, which carries a much better long-term outcome (approx. 50-80% normal development) compared to generalized or fragmented patterns. **2. Why the Other Options are Incorrect:** * **Myoclonic Seizures:** These carry the **worst prognosis**. They are often associated with severe underlying brain dysfunction, such as Inborn Errors of Metabolism (e.g., Non-ketotic hyperglycinemia) or Early Myoclonic Encephalopathy (EME). * **Tonic Seizures:** These are frequently seen in premature infants with Intraventricular Hemorrhage (IVH) or severe Hypoxic-Ischemic Encephalopathy (HIE), indicating significant brainstem involvement and a poor prognosis. * **Opsoclonus:** This is not a seizure type but a movement disorder (rapid, involuntary, multivectorial eye movements). In pediatrics, it is classically associated with Neuroblastoma (Opsoclonus-Myoclonus-Ataxia Syndrome). **High-Yield Clinical Pearls for NEET-PG:** * **Most common type** of neonatal seizure: **Subtle seizures** (e.g., bicycling, rowing, apnea, lip-smacking). * **Best prognosis:** Focal clonic seizures. * **Worst prognosis:** Myoclonic seizures. * **First-line drug:** Phenobarbital remains the drug of choice for neonatal seizures (Levetiracetam is an emerging alternative). * **Most common cause:** Hypoxic-Ischemic Encephalopathy (HIE) is the #1 cause of seizures in term neonates.

Q: Jaundice appearing at or within 24 hours of birth is commonly due to?

Erythroblastosis. **Explanation:** Jaundice appearing within the first 24 hours of life is always considered **pathological**. The most common cause of early-onset jaundice is **hemolytic disease of the newborn**, specifically **Erythroblastosis fetalis** (Rh isoimmunization or ABO incompatibility). **1. Why Erythroblastosis is Correct:** In Erythroblastosis, maternal antibodies cross the placenta and cause rapid destruction of fetal red blood cells. This massive hemolysis leads to a surge in unconjugated bilirubin immediately after birth, often manifesting as clinical jaundice within hours. Other causes of jaundice <24 hours include intrauterine infections (TORCH) and G6PD deficiency. **2. Why Other Options are Incorrect:** * **Congenital hyperbilirubinemia:** Conditions like Crigler-Najjar or Gilbert syndrome typically manifest later in the neonatal period or childhood, not usually within the first 24 hours. * **Biliary atresia:** This is a cause of conjugated hyperbilirubinemia. It typically presents with persistent jaundice and pale stools between **2 to 4 weeks** of life, rather than on the first day. * **Physiological jaundice:** By definition, physiological jaundice **never** appears within the first 24 hours. It typically appears on the 2nd or 3rd day, peaks by the 5th day, and disappears by the 7th to 10th day. **Clinical Pearls for NEET-PG:** * **Rule of Thumb:** Jaundice in the first 24 hours is pathological until proven otherwise. * **Investigation of Choice:** Direct Coombs Test (DCT) is used to diagnose immune-mediated hemolysis (Erythroblastosis). * **Kramer’s Rule:** Used to clinically estimate bilirubin levels based on the cephalocaudal progression of jaundice (Face: ~5 mg/dL; Palms/Soles: >15 mg/dL).

Q: A term neonate with a birth weight of 3980g showed the following feature. All of the following can be expected in this baby EXCEPT?

Hypercalcemia. ***Hypercalcemia*** - **Infants of diabetic mothers (IDM)** typically develop **hypocalcemia** due to maternal diabetes causing **hypomagnesemia**, which suppresses **parathyroid hormone (PTH)** release. - The **hyperinsulinemic state** in utero also interferes with normal calcium homeostasis, making hypercalcemia unlikely. *Increased risk of congenital heart diseases* - IDMs have a **3-5 fold increased risk** of congenital heart defects, particularly **ventricular septal defects** and **transposition of great arteries**. - **Maternal hyperglycemia** during organogenesis (weeks 3-8) disrupts normal cardiac development through oxidative stress. *Polycythemia* - **Chronic intrauterine hypoxia** from maternal diabetes stimulates increased **erythropoietin production** and red blood cell formation. - **Hematocrit >65%** is common in IDMs due to compensatory response to relative tissue hypoxia from maternal hyperglycemia. *Hypoglycemia* - **Fetal hyperinsulinemia** develops in response to maternal hyperglycemia, leading to **rebound hypoglycemia** after birth when maternal glucose supply is cut off. - Occurs within **30 minutes to 2 hours** after delivery and is one of the most common complications in IDMs.

Q: All of the following are risk factors for neonatal hypocalcemia except?

Exclusive breastfeeding. **Explanation:** Neonatal hypocalcemia is defined as serum calcium <7 mg/dL. It is categorized into early-onset (first 72 hours) and late-onset (after 72 hours). **Why Exclusive Breastfeeding is the Correct Answer:** Exclusive breastfeeding is **not** a risk factor for neonatal hypocalcemia; in fact, it is the physiological norm. Human milk has a low phosphorus content and an ideal Calcium:Phosphorus ratio (2:1), which promotes optimal calcium absorption and prevents the suppression of parathyroid hormone (PTH). **Analysis of Incorrect Options:** * **Maternal Hyperparathyroidism:** High maternal calcium levels cross the placenta, suppressing the fetal parathyroid glands. Post-delivery, the neonate’s suppressed glands cannot maintain calcium levels, leading to hypocalcemia. * **Exchange Transfusion:** Citrate is used as an anticoagulant in stored blood. It binds to ionized calcium, leading to acute hypocalcemia during or after the procedure. * **Cow Milk:** Cow’s milk has a very high phosphorus content. High phosphate levels lead to hyperphosphatemia, which reciprocally lowers serum calcium and suppresses PTH (Late-onset hypocalcemia). **NEET-PG High-Yield Pearls:** * **Early-onset Hypocalcemia:** Seen in IDM (Infant of Diabetic Mother), prematurity, and birth asphyxia. * **Late-onset Hypocalcemia:** Primarily caused by high phosphate intake (cow milk) or Vitamin D deficiency. * **Clinical Sign:** Chvostek sign and Trousseau sign are often absent in neonates; they more commonly present with jitteriness, seizures, or a prolonged QTc interval on ECG. * **Treatment:** Acute symptomatic cases are treated with **10% Calcium Gluconate** (2 ml/kg) under cardiac monitoring.

Q: What is the most specific congenital abnormality in a baby born to a diabetic woman?

Sacral agenesis. **Explanation:** In infants of diabetic mothers (IDM), the risk of congenital malformations is 3–4 times higher than in the general population, primarily due to poor glycemic control during organogenesis (the first trimester). **1. Why Sacral Agenesis is Correct:** **Sacral agenesis** (also known as Caudal Regression Syndrome) is considered the **most specific** abnormality associated with maternal diabetes. While it is rare in the general population, a baby born with this condition has a very high probability (nearly 200 times higher risk) of having a mother with diabetes. It involves the incomplete development of the lower spine and can be associated with gastrointestinal and genitourinary anomalies. **2. Analysis of Incorrect Options:** * **A. Ventricular Septal Defect (VSD):** This is the **most common** cardiac malformation in IDMs. However, it is not the most specific, as VSDs occur frequently in the general population due to various other etiologies. * **C. Meningomyelocele:** Neural tube defects are common in IDMs, but they are not as pathognomonic or specific as sacral agenesis. * **D. Transposition of the Great Arteries (TGA):** While TGA is a classic cardiac association with maternal diabetes, VSD remains more frequent, and sacral agenesis remains more specific. **High-Yield Clinical Pearls for NEET-PG:** * **Most Common Malformation Overall:** Cardiovascular system anomalies. * **Most Common Specific Cardiac Defect:** Ventricular Septal Defect (VSD). * **Most Specific Cardiac Defect:** Transposition of the Great Arteries (TGA). * **Most Specific Malformation Overall:** Sacral Agenesis (Caudal Regression Syndrome). * **Transient Hypertrophic Cardiomyopathy:** Often involves asymmetric septal hypertrophy, which usually resolves spontaneously after birth. * **Prevention:** Strict preconception glycemic control (HbA1c < 6.5%) significantly reduces the risk of these anomalies.

Question 1

For a neonate at 48 hours of birth with a history of non-passage of meconium, what is the next step in evaluation?

Accepted Answer

Lower GI study

Answer

Sweat chloride level

Answer

CFTR mutation analysis

Answer

Manometry

Question 2

Low birth weight baby is defined as one whose birth weight is:

Accepted Answer

Less than 2500 g

Answer

Less than 1800 g

Answer

Less than 2000 g

Answer

Less than 3000 g

Question 3

Why are newborn babies prone to hypoglycemia?

Accepted Answer

Low body glycogen reserves

Answer

Impaired glucose metabolism

Answer

Prematurity

Answer

All of the above

Question 4

Which type of neonatal seizure has the best prognosis?

Accepted Answer

Focal

Answer

Myoclonic

Answer

Tonic clonic

Answer

Opsoclonus

Question 5

The most common cause of vaginal bleeding in a neonate is:

Accepted Answer

Hormone withdrawal

Answer

Sarcoma botryoides

Answer

Birth trauma

Answer

Bleeding disorder

Question 6

Jaundice appearing at or within 24 hours of birth is commonly due to?

Accepted Answer

Erythroblastosis

Answer

Congenital hyperbilirubinemia

Answer

Biliary atresia

Answer

Physiological jaundice

Question 7

A term neonate with a birth weight of 3980g showed the following feature. All of the following can be expected in this baby EXCEPT?

Accepted Answer

Hypercalcemia

Answer

Increased risk of congenital heart diseases

Answer

Polycythemia

Answer

Hypoglycemia

Question 8

All of the following are risk factors for neonatal hypocalcemia except?

Accepted Answer

Exclusive breastfeeding

Answer

Maternal hyperparathyroidism

Answer

Exchange transfusion

Answer

Cow milk

Question 9

A child develops respiratory distress and a scaphoid abdomen 2 days after birth. Breath sounds are decreased on the left side. After bag and mask ventilation, an endotracheal tube is inserted, and the maximal cardiac impulse shifts to the right side. What is the next step in management?

Accepted Answer

Confirm the position of the endotracheal tube

Answer

Emergency surgery

Answer

Nasogastric tube insertion

Answer

Chest X-ray

Question 10

What is the most specific congenital abnormality in a baby born to a diabetic woman?

Accepted Answer

Sacral agenesis

Answer

Ventricular Septal defect

Answer

Meningomyelocele

Answer

Transposition of great arteries

Neonatology — MCQs

Neonatology — MCQs

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