Four days after delivery, a 1400-g (3-lb 1-oz) newborn has a tonic seizure that lasts for 30 seconds. Over the past 24 hours, he has become increasingly lethargic. He was born at 31 weeks' gestation. Antenatal period was complicated by chorioamnionitis. Apgar scores were 4 and 5 at 1 and 5 minutes, respectively. He appears ill. His pulse is 130/min, respirations are 53/min and irregular, and blood pressure is 67/35 mm Hg. Examination shows a bulging anterior fontanelle. The pupils are equal and react sluggishly to light. Examination shows slow, conjugate back and forth movements of the eyes. Muscle tone is decreased in all extremities. The lungs are clear to auscultation. Which of the following is the most likely underlying cause?
Q22
Two days after delivery, a 4300-g (9-lb 8-oz) newborn has difficulty feeding and has become increasingly lethargic. His cry has become weak. He was born at term. His mother has a history of intravenous drug use. His temperature is 36.4°C (96.5°F), pulse is 170/min, respirations are 62/min, and blood pressure is 70/48 mm Hg. Examination shows midfacial hypoplasia, diaphoresis, and tremor of the lower extremities. Macroglossia is present. There are folds in the posterior auricular cartilage. The left lower extremity is larger than the right lower extremity. Abdominal examination shows an umbilical hernia. The liver is palpated 4 cm below the right costal margin. Neurological examination shows decreased tone in all extremities. Which of the following is the most appropriate intervention?
Q23
A newborn male is evaluated one minute after birth. He was born at 38 weeks gestation to a 28-year-old gravida 3 via vaginal delivery. The patient’s mother received sporadic prenatal care, and the pregnancy was complicated by gestational diabetes. The amniotic fluid was clear. The patient’s pulse is 70/min, and his breathing is irregular with a slow, weak cry. He whimpers in response to a soft pinch on the thigh, and he has moderate muscle tone with some flexion of his extremities. His body is pink and his extremities are blue. The patient is dried with a warm towel and then placed on his back on a flat warmer bed. His mouth and nose are suctioned with a bulb syringe.
Which of the following is the best next step in management?
Q24
A 27-year-old woman gives birth to a boy at 36 weeks gestational age. The infant weighs 4022 grams at birth, is noted to have a malformed sacrum, and appears to be in respiratory distress. Apgar scores are 5 and 7 at 1 minute and 5 minutes respectively. Hours after birth, the infant is found to be irritable, bradycardic, cyanotic, and hypotonic, and the infant's serum is sent to the laboratory for evaluation. Which of the following abnormalities would you expect to observe in this infant?
Q25
A 2-week-old boy is brought to the emergency department after he was found to have blood in his stool. The mother says the baby was born by home birth at 38 weeks without complications. The mother denies fever, vomiting, or rash but says the baby has been fussier recently. The mother denies a family history of any similar problems. On exam, the patient is well-developed and meets all developmental markers. His heart rate is tachycardic but with regular rhythms. There is oozing blood from the umbilical site which has not fully healed. A guaiac stool test is positive. What is the underlying cause of this presentation?
Q26
A 1-week-old infant who was born at home is rushed to the emergency room by his parents. His parents are recent immigrants who do not speak English. Through a translator, the child's parents say that during play with the infant, the infant's body became rigid and his mouth 'locked up'. The child likely suffered from a(n):
Q27
A first time mother of a healthy, full term, newborn girl is anxious about sudden infant death syndrome. Which of the following pieces of advice can reduce the risk of SIDS?
Q28
A 3-week-old newborn male is brought to the physician because of increasing yellowing of his eyes and skin for 2 weeks. The mother has noticed that his stools have been paler than usual for the past week. He is exclusively formula fed, and feeds every 4 hours with a strong sucking reflex. The patient was delivered vaginally at 39 weeks' gestation to a healthy woman without any complications. Vital signs are within normal limits. He is at the 50th percentile for length and at the 65th percentile for weight. Examination shows scleral icterus and jaundice. Abdominal examination reveals a palpable liver 2 cm below the right costal margin without splenomegaly. Serum studies show:
Bilirubin
Total 17 mg/dL
Direct 13.3 mg/dL
Alkaline phosphatase 1700 U/L
AST 53 U/L
ALT 45 U/L
γ-Glutamyl transferase 174 U/L
Blood group B positive
This patient is at increased risk of developing which of the following?
Q29
A female neonate born to a 21-year-old G2P1 had jaundice at 8 hours of life. The neonate’s red blood cell type was A+, while the mother’s RBC type was O+. The mother’s anti-A antibody titer was elevated. A screen for a fetomaternal bleed was negative. The direct Coombs test was weakly positive. The infant’s hemoglobin and total bilirubin were 10.6g/dL and 7 mg/dL, respectively. The erythrocyte glucose-6-phosphate was normal and the sickle cell test was negative. A peripheral blood smear showed normocytic normochromic RBCs, nucleated RBCs, and reticulocytes. What is the most likely diagnosis?
Q30
A 10-month-old girl is brought to the physician by her mother because of fever and irritability for the past 2 days. The mother says that the girl's diapers have smelled bad since the symptoms started. The patient has had some clear nasal secretions over the past week. Two months ago, she was brought to the emergency department for a simple febrile seizure. Otherwise, she has been healthy and her immunizations are up-to-date. She appears ill. She is at the 50th percentile for height and weight. Her temperature is 39.1°C (102.3°F), pulse is 138/min, respirations are 26/min, and blood pressure is 75/45 mm Hg. Oropharyngeal examination shows a mild postnasal drip. The remainder of the examination shows no abnormalities. Laboratory studies show:
Hemoglobin 12.4 g/dL
Leukocyte count
8,000/mm3
Serum
Na+ 138 mEq/L
K+ 4.0 mEq/L
Cl- 100 mEq/L
Creatinine 0.5 mg/dL
Urine
RBC 1–2/hpf
WBC 18–20 WBCs/hpf
Nitrites positive
Bacteria gram-negative rods
Nasal swab for respiratory syncytial virus, influenza A, and influenza B antigens is negative. Urine culture grows > 105 colony forming units (CFU)/mL of E. coli. Treatment with acetaminophen and cefixime is started. Two days later, her symptoms have improved. Which of the following is the most appropriate next step in management?
Neonatal infections US Medical PG Practice Questions and MCQs
Question 21: Four days after delivery, a 1400-g (3-lb 1-oz) newborn has a tonic seizure that lasts for 30 seconds. Over the past 24 hours, he has become increasingly lethargic. He was born at 31 weeks' gestation. Antenatal period was complicated by chorioamnionitis. Apgar scores were 4 and 5 at 1 and 5 minutes, respectively. He appears ill. His pulse is 130/min, respirations are 53/min and irregular, and blood pressure is 67/35 mm Hg. Examination shows a bulging anterior fontanelle. The pupils are equal and react sluggishly to light. Examination shows slow, conjugate back and forth movements of the eyes. Muscle tone is decreased in all extremities. The lungs are clear to auscultation. Which of the following is the most likely underlying cause?
A. Congenital hydrocephalus
B. Germinal matrix hemorrhage (Correct Answer)
C. Galactose-1-phosphate uridylyltransferase deficiency
D. Phenylalanine hydroxylase deficiency
E. Apoptosis of lower motor neurons
Explanation: ***Germinal matrix hemorrhage***
- This condition is most common in **premature infants** (born at 31 weeks' gestation) and is exacerbated by perinatal insults such as **chorioamnionitis** and **low Apgar scores**, leading to rupture of fragile germinal matrix vessels.
- The clinical presentation of a **tonic seizure**, increasing **lethargy**, **bulging fontanelle**, sluggish pupillary reflexes, and abnormal eye movements (slow conjugate back-and-forth movements) points towards increased **intracranial pressure** due to intraventricular hemorrhage.
- While GMH typically occurs within the first 72 hours of life, the **progressive symptoms over 24 hours** starting on day 3-4 with the acute presentation on day 4 is consistent with **evolving IVH with hydrocephalus**, which can manifest with delayed clinical deterioration as blood obstructs CSF flow.
- Among the given options, this is the **most likely diagnosis** given the prematurity, risk factors, and signs of increased ICP.
*Congenital hydrocephalus*
- While it can present with a **bulging fontanelle**, congenital hydrocephalus typically manifests with gradual progressive head enlargement rather than acute onset of seizures and rapid neurological decline.
- It would typically be identified antenatally or soon after birth due to progressive macrocephaly, and lacks the specific risk factors (prematurity, chorioamnionitis) that make hemorrhage more likely in this context.
*Galactose-1-phosphate uridylyltransferase deficiency*
- This enzyme deficiency causes **galactosemia**, a metabolic disorder presenting with **jaundice**, hepatomegaly, vomiting, and feeding difficulties, usually after the initiation of milk feeds.
- Seizures can occur in severe cases, but the primary symptoms are metabolic (hypoglycemia, liver dysfunction) and not typically linked to a bulging fontanelle or the specific perinatal risk factors (prematurity, chorioamnionitis) described.
*Phenylalanine hydroxylase deficiency*
- This deficiency leads to **phenylketonuria (PKU)**, a metabolic disorder that primarily causes neurological damage if untreated, typically presenting with developmental delay, intellectual disability, seizures, and microcephaly **later in infancy** (months, not days).
- It does not present acutely with bulging fontanelle and seizures in the first week of life, nor does it correlate with prematurity or chorioamnionitis as risk factors.
*Apoptosis of lower motor neurons*
- This is characteristic of conditions like **spinal muscular atrophy (SMA)**, which typically presents with progressive **muscle weakness**, **hypotonia**, and absent deep tendon reflexes without acute onset seizures.
- The neurological signs in this infant—**seizures**, **bulging fontanelle**, and **increased intracranial pressure**—are not features of lower motor neuron disease, which affects the anterior horn cells and peripheral motor function, not higher cortical or intracranial processes.
Question 22: Two days after delivery, a 4300-g (9-lb 8-oz) newborn has difficulty feeding and has become increasingly lethargic. His cry has become weak. He was born at term. His mother has a history of intravenous drug use. His temperature is 36.4°C (96.5°F), pulse is 170/min, respirations are 62/min, and blood pressure is 70/48 mm Hg. Examination shows midfacial hypoplasia, diaphoresis, and tremor of the lower extremities. Macroglossia is present. There are folds in the posterior auricular cartilage. The left lower extremity is larger than the right lower extremity. Abdominal examination shows an umbilical hernia. The liver is palpated 4 cm below the right costal margin. Neurological examination shows decreased tone in all extremities. Which of the following is the most appropriate intervention?
A. Administer naloxone
B. Administer 3% saline
C. Administer thyroxine
D. Administer glucose (Correct Answer)
E. Administer ampicillin and gentamicin
Explanation: ***Administer glucose***
- The presented symptoms, including **lethargy**, **weak cry**, **diaphoresis**, **tremor**, and **hypotonia**, are highly suggestive of **neonatal hypoglycemia**, which requires immediate treatment.
- The physical findings (macroglossia, hemihypertrophy, umbilical hernia, hepatomegaly) suggest **Beckwith-Wiedemann syndrome (BWS)**, a condition associated with **high risk of severe hypoglycemia** in the neonatal period.
- The **large for gestational age (LGA)** birth weight (4300g) further increases hypoglycemia risk.
- **Immediate glucose administration** is life-saving and takes priority over other diagnostic considerations.
*Administer naloxone*
- While the mother has a history of intravenous drug use, the clinical presentation is not consistent with acute opioid toxicity (which would present with respiratory depression, miosis, and decreased consciousness immediately after birth).
- The constellation of dysmorphic features and metabolic symptoms points to **hypoglycemia**, not opioid exposure.
- Naloxone is contraindicated in neonates of opioid-dependent mothers as it may precipitate severe withdrawal.
*Administer 3% saline*
- **Hypertonic saline (3% saline)** is used to treat **severe symptomatic hyponatremia** with seizures or altered mental status.
- There is no clinical indication for hyponatremia in this case; the symptoms are classic for **hypoglycemia**.
- Administering hypertonic saline without documented hyponatremia could cause dangerous complications.
*Administer thyroxine*
- **Macroglossia**, **umbilical hernia**, **hypotonia**, and **posterior auricular folds** can be signs of **congenital hypothyroidism**.
- However, congenital hypothyroidism presents with gradual onset of symptoms over weeks, not acute decompensation at 2 days of life.
- The acute symptoms (diaphoresis, tremors, lethargy) and associated findings (hemihypertrophy, hepatomegaly) are more consistent with **BWS-associated hypoglycemia**.
- Hypothyroidism workup can be pursued after stabilizing the acute hypoglycemia.
*Administer ampicillin and gentamicin*
- **Broad-spectrum antibiotics** are used for suspected **neonatal sepsis**, which can present with lethargy, poor feeding, and temperature instability.
- While sepsis should always be considered in an ill neonate, the specific constellation of dysmorphic features (macroglossia, hemihypertrophy, umbilical hernia) strongly suggests **Beckwith-Wiedemann syndrome**.
- The symptoms of diaphoresis and tremor are more specific for **hypoglycemia** than infection.
- A sepsis workup may be warranted, but **correcting hypoglycemia is the most urgent intervention**.
Question 23: A newborn male is evaluated one minute after birth. He was born at 38 weeks gestation to a 28-year-old gravida 3 via vaginal delivery. The patient’s mother received sporadic prenatal care, and the pregnancy was complicated by gestational diabetes. The amniotic fluid was clear. The patient’s pulse is 70/min, and his breathing is irregular with a slow, weak cry. He whimpers in response to a soft pinch on the thigh, and he has moderate muscle tone with some flexion of his extremities. His body is pink and his extremities are blue. The patient is dried with a warm towel and then placed on his back on a flat warmer bed. His mouth and nose are suctioned with a bulb syringe.
Which of the following is the best next step in management?
A. Supplemental oxygen via nasal cannula and reassessment of Apgar score at 5 minutes
B. Chest compressions and bag-mask ventilation
C. Endotracheal intubation and mechanical ventilation
D. Intravenous epinephrine and reassessment of Apgar score at 5 minutes
E. Positive pressure ventilation and reassessment of Apgar score at 5 minutes (Correct Answer)
Explanation: ***Positive pressure ventilation and reassessment of Apgar score at 5 minutes***
- The newborn's **heart rate is 70/min**, which is below the target of >100/min that warrants **positive pressure ventilation (PPV)**. His irregular breathing and central cyanosis (pink body, blue extremities indicate acrocyanosis, but the overall picture suggests a need for support), along with the low heart rate, indicate inadequate respiratory effort and circulation.
- After initial steps (drying, stimulating, suctioning), if the heart rate remains below 100/min or the infant has gasping/apnea, PPV should be initiated immediately. Reassessing the **Apgar score at 5 minutes** is standard practice.
*Supplemental oxygen via nasal cannula and reassessment of Apgar score at 5 minutes*
- While supplemental oxygen is important, **nasal cannula** provides low-flow oxygen and is insufficient for a newborn with a heart rate of 70/min and irregular breathing. This patient requires more robust respiratory support.
- Oxygen supplementation alone would not address the inadequate respiratory effort and bradycardia to the necessary extent.
*Chest compressions and bag-mask ventilation*
- **Chest compressions** are indicated when the heart rate is below 60/min despite adequate positive pressure ventilation for at least 30 seconds.
- In this case, the heart rate is 70/min, so chest compressions are not yet indicated. The priority is to establish effective ventilation.
*Endotracheal intubation and mechanical ventilation*
- **Endotracheal intubation** is considered if PPV via bag-mask is ineffective, if prolonged resuscitation is anticipated, or if meconium aspiration is present.
- This is a more invasive step and not the immediate next step when PPV can be initiated first to improve heart rate and respiration.
*Intravenous epinephrine and reassessment of Apgar score at 5 minutes*
- **Intravenous epinephrine** is administered only if the heart rate remains below 60/min despite 30 seconds of effective positive pressure ventilation and 60 seconds of effective chest compressions.
- The current heart rate is 70/min, and the prior steps of resuscitation have not yet included effective PPV for the required duration, so epinephrine is not yet indicated.
Question 24: A 27-year-old woman gives birth to a boy at 36 weeks gestational age. The infant weighs 4022 grams at birth, is noted to have a malformed sacrum, and appears to be in respiratory distress. Apgar scores are 5 and 7 at 1 minute and 5 minutes respectively. Hours after birth, the infant is found to be irritable, bradycardic, cyanotic, and hypotonic, and the infant's serum is sent to the laboratory for evaluation. Which of the following abnormalities would you expect to observe in this infant?
A. Hypoinsulinemia
B. Hypoglycemia (Correct Answer)
C. Hyperglycemia
D. Hypermagnesemia
E. Hypercalcemia
Explanation: ***Hypoglycemia***
- The infant is macrosomic (4022g at 36 weeks), indicating potential **maternal diabetes**, which often leads to fetal **hyperinsulinemia** and subsequent rapid glucose consumption after birth.
- Symptoms like irritability, bradycardia, cyanosis, and hypotonia are classic signs of neonatal hypoglycemia due to inadequate glucose supply for metabolic demands.
*Hypoinsulinemia*
- Maternal diabetes typically causes **fetal hyperglycemia**, leading to reactive fetal **hyperinsulinemia** as the fetal pancreas attempts to regulate glucose.
- After birth, the sudden cessation of maternal glucose supply to a hyperinsulinemic infant rapidly leads to hypoglycemia, not hypoinsulinemia.
*Hyperglycemia*
- While the infant experienced hyperglycemia *in utero* due to maternal diabetes, after birth and the separation from the maternal glucose supply, the infant's own hyperinsulinemia would rapidly consume endogenous glucose, leading to **hypoglycemia**.
- Neonatal hyperglycemia is more common in stressed or very low birth weight infants receiving excessive intravenous glucose, which is not described.
*Hypermagnesemia*
- **Hypermagnesemia** in newborns is typically associated with maternal treatment with magnesium sulfate for preeclampsia, which is not mentioned in the clinical scenario.
- Common symptoms include respiratory depression, hypotonia, and decreased reflexes, but **hypoglycemia** is a more direct and expected complication given the infant's macrosomia and maternal diabetes association.
*Hypercalcemia*
- Neonatal **hypercalcemia** is rare and is often associated with genetic conditions like Williams syndrome or idiopathic infantile hypercalcemia.
- Hypoglycemia is a much more common finding in infants of diabetic mothers, and there is no indication for hypercalcemia in this presentation.
Question 25: A 2-week-old boy is brought to the emergency department after he was found to have blood in his stool. The mother says the baby was born by home birth at 38 weeks without complications. The mother denies fever, vomiting, or rash but says the baby has been fussier recently. The mother denies a family history of any similar problems. On exam, the patient is well-developed and meets all developmental markers. His heart rate is tachycardic but with regular rhythms. There is oozing blood from the umbilical site which has not fully healed. A guaiac stool test is positive. What is the underlying cause of this presentation?
A. Factor VIII deficiency
B. Bacterial infection
C. Vitamin B12 deficiency
D. Vitamin K deficiency (Correct Answer)
E. Factor IX deficiency
Explanation: ***Vitamin K deficiency***
- The bleeding in a 2-week-old infant, specifically gastrointestinal bleeding (blood in stool) and umbilical oozing, is highly suspicious for **Vitamin K deficiency bleeding (VKDB)**, particularly given the home birth setting where prophylactic vitamin K administration may have been missed.
- The mother's denial of fever, vomiting, or rash, and the absence of a family history of bleeding disorders, makes other conditions less likely, while the isolated bleeding signs point strongly to a **coagulation factor deficiency** related to vitamin K.
*Factor VIII deficiency*
- **Hemophilia A (Factor VIII deficiency)** typically presents with spontaneous bleeding into joints and muscles, or prolonged bleeding after trauma/surgery.
- While it can manifest in neonates (e.g., intracranial hemorrhage), it's less commonly associated with **umbilical stump bleeding** or **gastrointestinal bleeding** as the primary presentation in this early neonatal period compared to VKDB, and there is no family history of a similar problem.
*Bacterial infection*
- A bacterial infection causing gastrointestinal bleeding would likely present with other systemic symptoms such as **fever, vomiting, lethargy**, or signs of sepsis, which are explicitly denied by the mother.
- Although some severe infections can cause disseminated intravascular coagulation (DIC) and bleeding, isolated bleeding without other signs of infection makes this less probable.
*Vitamin B12 deficiency*
- Vitamin B12 deficiency is primarily associated with **megaloblastic anemia** and **neurological symptoms**, not acute bleeding.
- It is not a direct cause of coagulation factor deficiencies resulting in acute bleeding in neonates.
*Factor IX deficiency*
- **Hemophilia B (Factor IX deficiency)**, like Hemophilia A, presents similarly with joint and muscle hematomas or prolonged bleeding, and usually has a family history of X-linked bleeding.
- The absence of a family history and the specific constellation of gastrointestinal and umbilical bleeding make **VKDB** a more direct fit, as Factor IX is also a vitamin K-dependent clotting factor, but the overall clinical picture without a family history points more broadly to VKDB due to lack of prophylaxis.
Question 26: A 1-week-old infant who was born at home is rushed to the emergency room by his parents. His parents are recent immigrants who do not speak English. Through a translator, the child's parents say that during play with the infant, the infant's body became rigid and his mouth 'locked up'. The child likely suffered from a(n):
A. Infection of the colon
B. Infection of a foot ulcer
C. Infection of the umbilical stump (Correct Answer)
D. Intrauterine infection
E. Dental infection
Explanation: ***Infection of the umbilical stump***
- The symptoms described—body rigidity and a "locked up" mouth (likely **trismus** or lockjaw)—are classic signs of neonatal **tetanus**.
- Neonatal tetanus most commonly occurs in infants born at home without sterile delivery practices, where the **umbilical stump** is contaminated with *Clostridium tetani* spores.
*Infection of the colon*
- While *Clostridium difficile* infections can occur in infants, they typically cause **diarrhea** and **colitis**, not muscle rigidity or trismus.
- Colonic infections are not a primary cause of neonatal tetanus.
*Infection of a foot ulcer*
- A foot ulcer in a 1-week-old infant is highly unlikely and the symptoms do not align with typical signs of a localized infection.
- Although tetanus can enter through skin wounds, a foot ulcer in an infant is not a common portal of entry in the neonatal period.
*Intrauterine infection*
- Intrauterine infections (e.g., TORCH infections) can cause various congenital anomalies or systemic illness.
- They typically do not present with the acute, severe muscle rigidity and trismus characteristic of tetanus in a 1-week-old.
*Dental infection*
- A 1-week-old infant does not have erupted teeth, making a dental infection an impossible cause of the described symptoms.
- Dental infections cause local pain, swelling, and fever, not generalized muscle rigidity.
Question 27: A first time mother of a healthy, full term, newborn girl is anxious about sudden infant death syndrome. Which of the following pieces of advice can reduce the risk of SIDS?
A. Sleep supine in a crib with bumpers, head propped up on a pillow, and wrapped in a warm blanket
B. Sleep supine in a crib with bumpers, head propped up on a pillow, and wrapped in an infant sleeper
C. Sleep supine in the parent's bed and use a pacifier after 1 month of age
D. Sleep supine in a crib without bumpers, use a pacifier after 1 month of age, and use a home apnea monitor
E. Sleep supine in a crib without bumpers, use a pacifier after 1 month of age, and avoid smoking (Correct Answer)
Explanation: ***Sleep supine in a crib without bumpers, use a pacifier after 1 month of age, and avoiding smoking***
- **Sleeping supine** (on the back) is the most critical recommendation to reduce SIDS risk, and a **crib without bumpers** and other soft bedding reduces smothering hazards.
- **Pacifier use** after the first month of age has been shown to be protective, and **avoiding smoking** around the infant is crucial as exposure to tobacco smoke significantly increases SIDS risk.
*Sleep supine in a crib with bumpers, head propped up on a pillow, and wrapped in a warm blanket*
- While **sleeping supine** is correct, **bumpers, pillows, and loose blankets** in the crib are significant risk factors for SIDS, as they can cause accidental suffocation.
- The use of **pillows** is not recommended for infants due to the risk of airway obstruction and suffocation.
*Sleep supine in a crib with bumpers, head propped up on a pillow, and wrapped in an infant sleeper*
- Similar to the previous option, **bumpers and a pillow** are unsafe as they pose a suffocation risk and should be avoided in an infant's sleep environment.
- While an **infant sleeper** (or sleep sack) is generally safer than a loose blanket, the presence of bumpers and a pillow negates this benefit.
*Sleep supine in the parent's bed and use a pacifier after 1 month of age*
- **Co-sleeping (sharing a bed with parents)** significantly increases the risk of SIDS and accidental suffocation, especially if parents smoke, are impaired, or if heavy bedding is present.
- Although **pacifier use** is recommended, sleeping in the parent's bed is a major risk factor that outweighs any potential benefit here.
*Sleep supine in a crib without bumpers, use a pacifier after 1 month of age, and use a home apnea monitor*
- While **sleeping supine** in a **crib without bumpers** and **pacifier use** are correct recommendations, **home apnea monitors** are not recommended for routine SIDS prevention in healthy infants.
- Apnea monitors have not been shown to reduce the incidence of SIDS and can lead to false alarms and unnecessary anxiety without proven benefit.
Question 28: A 3-week-old newborn male is brought to the physician because of increasing yellowing of his eyes and skin for 2 weeks. The mother has noticed that his stools have been paler than usual for the past week. He is exclusively formula fed, and feeds every 4 hours with a strong sucking reflex. The patient was delivered vaginally at 39 weeks' gestation to a healthy woman without any complications. Vital signs are within normal limits. He is at the 50th percentile for length and at the 65th percentile for weight. Examination shows scleral icterus and jaundice. Abdominal examination reveals a palpable liver 2 cm below the right costal margin without splenomegaly. Serum studies show:
Bilirubin
Total 17 mg/dL
Direct 13.3 mg/dL
Alkaline phosphatase 1700 U/L
AST 53 U/L
ALT 45 U/L
γ-Glutamyl transferase 174 U/L
Blood group B positive
This patient is at increased risk of developing which of the following?
A. Dark pigmentation on liver biopsy
B. Hepatic encephalopathy
C. Kernicterus
D. Hepatocellular carcinoma
E. Early liver cirrhosis (Correct Answer)
Explanation: ***Early liver cirrhosis***
- The combination of **persistent jaundice**, **pale stools**, significantly **elevated direct bilirubin**, and **markedly high alkaline phosphatase and γ-glutamyl transferase (GGT)** in a 3-week-old infant points to **biliary atresia**.
- **Biliary atresia** is a progressive fibrosing obliterative cholangiopathy that, if untreated, rapidly leads to **biliary cirrhosis** and liver failure/death within the first year of life.
*Dark pigmentation on liver biopsy*
- **Dark pigmentation** (black liver) on liver biopsy is characteristic of **Dubin-Johnson syndrome**, a rare autosomal recessive disorder of bilirubin metabolism.
- While it causes **conjugated hyperbilirubinemia**, the clinical picture (e.g., profound elevation of ALP and GGT, rapidly progressive liver damage) is not consistent with Dubin-Johnson syndrome.
*Hepatic encephalopathy*
- **Hepatic encephalopathy** is a complication of advanced liver disease, characterized by altered mental status due to the accumulation of toxins (e.g., ammonia) that the liver fails to clear.
- While this patient is at risk of eventually developing liver failure and its complications, **early liver cirrhosis** is a more direct and immediate outcome of untreated biliary atresia in an infant.
*Kernicterus*
- **Kernicterus** (bilirubin encephalopathy) is caused by the deposition of **unconjugated (indirect) bilirubin** in the brain, leading to neurological damage.
- This patient presents with predominantly **conjugated (direct) hyperbilirubinemia**, which typically does not cross the blood-brain barrier and therefore does not cause kernicterus.
*Hepatocellular carcinoma*
- **Hepatocellular carcinoma (HCC)** is a primary liver cancer, typically seen in older children or adults with chronic liver disease (e.g., chronic viral hepatitis, cirrhosis for many years).
- While long-standing, untreated liver cirrhosis can increase the risk of HCC, it is not an immediate or early complication in a 3-week-old infant with presumed biliary atresia.
Question 29: A female neonate born to a 21-year-old G2P1 had jaundice at 8 hours of life. The neonate’s red blood cell type was A+, while the mother’s RBC type was O+. The mother’s anti-A antibody titer was elevated. A screen for a fetomaternal bleed was negative. The direct Coombs test was weakly positive. The infant’s hemoglobin and total bilirubin were 10.6g/dL and 7 mg/dL, respectively. The erythrocyte glucose-6-phosphate was normal and the sickle cell test was negative. A peripheral blood smear showed normocytic normochromic RBCs, nucleated RBCs, and reticulocytes. What is the most likely diagnosis?
A. ABO incompatibility (Correct Answer)
B. Rh Incompatibility
C. Physiological jaundice
D. Sickle cell disease
E. G6PD deficiency
Explanation: ***ABO incompatibility***
- The mother is **O+** and the neonate is **A+**, indicating a mismatch, and the mother has **elevated anti-A antibody titers**. This scenario is classic for ABO incompatibility.
- The **weakly positive direct Coombs test** and early onset of jaundice (at 8 hours) with **hyperbilirubinemia** and **anemia** (Hb 10.6 g/dL) further support this diagnosis.
*Rh Incompatibility*
- This is unlikely because the mother is **Rh-positive (O+)**. Rh incompatibility primarily occurs when an **Rh-negative mother** carries an **Rh-positive fetus**.
- While Rh incompatibility can cause severe hemolytic disease, the mother's Rh status rules it out here.
*Physiological jaundice*
- **Physiological jaundice** typically appears after **24 hours of life**, not within 8 hours as observed in this case.
- The rapid rise in **bilirubin** (7 mg/dL at 8 hours) and **anemia** are more severe than usually seen in physiological jaundice.
*Sickle cell disease*
- The **sickle cell test was negative**, directly ruling out this condition.
- Symptoms of sickle cell disease, such as vaso-occlusive crises, do not typically present in the immediate neonatal period with early-onset jaundice in this manner.
*G6PD deficiency*
- The **erythrocyte glucose-6-phosphate was normal**, which excludes G6PD deficiency as the cause of hemolysis.
- G6PD deficiency can cause neonatal jaundice, but the normal enzyme level rules it out here.
Question 30: A 10-month-old girl is brought to the physician by her mother because of fever and irritability for the past 2 days. The mother says that the girl's diapers have smelled bad since the symptoms started. The patient has had some clear nasal secretions over the past week. Two months ago, she was brought to the emergency department for a simple febrile seizure. Otherwise, she has been healthy and her immunizations are up-to-date. She appears ill. She is at the 50th percentile for height and weight. Her temperature is 39.1°C (102.3°F), pulse is 138/min, respirations are 26/min, and blood pressure is 75/45 mm Hg. Oropharyngeal examination shows a mild postnasal drip. The remainder of the examination shows no abnormalities. Laboratory studies show:
Hemoglobin 12.4 g/dL
Leukocyte count
8,000/mm3
Serum
Na+ 138 mEq/L
K+ 4.0 mEq/L
Cl- 100 mEq/L
Creatinine 0.5 mg/dL
Urine
RBC 1–2/hpf
WBC 18–20 WBCs/hpf
Nitrites positive
Bacteria gram-negative rods
Nasal swab for respiratory syncytial virus, influenza A, and influenza B antigens is negative. Urine culture grows > 105 colony forming units (CFU)/mL of E. coli. Treatment with acetaminophen and cefixime is started. Two days later, her symptoms have improved. Which of the following is the most appropriate next step in management?
A. Obtain CT scan of the abdomen
B. Perform renal and bladder ultrasound (Correct Answer)
C. Repeat urine cultures in 4 weeks
D. Perform an intravenous pyelogram (IVP)
E. Start prophylaxis with trimethoprim-sulfamethoxazole
Explanation: ***Perform renal and bladder ultrasound***
- A **renal and bladder ultrasound (RBUS)** is the appropriate initial imaging study for children aged 2-24 months after a first febrile urinary tract infection (UTI) to assess for **structural abnormalities** of the urinary tract.
- This helps identify conditions like **hydronephrosis** or **vesicoureteral reflux (VUR)** that may predispose to recurrent UTIs and require further management.
*Obtain CT scan of the abdomen*
- A **CT scan** of the abdomen is generally not the initial imaging choice for pediatric UTIs due to **radiation exposure** and typically provides details less relevant than ultrasound for initial structural assessment.
- It may be considered in specific cases, such as to evaluate for **renal abscess** or other complex pathology if initial workup is inconclusive.
*Repeat urine cultures in 4 weeks*
- While follow-up urine cultures can be important to confirm eradication of infection, performing one **4 weeks later** without prior imaging or assessment for underlying causes is not the most immediate next step in management.
- The priority after treating an acute UTI, especially in a young child, is to investigate for **predisposing factors**.
*Perform an intravenous pyelogram (IVP)*
- An **intravenous pyelogram (IVP)** involves significant radiation exposure and contrast administration, making it a more invasive and less preferred initial imaging study compared to ultrasound in children.
- It has largely been replaced by **RBUS** and **voiding cystourethrogram (VCUG)** for evaluating urinary tract anatomy and reflux.
*Start prophylaxis with trimethoprim-sulfamethoxazole*
- **Antibiotic prophylaxis** is typically considered after identifying an underlying condition like high-grade **vesicoureteral reflux (VUR)**, or in children with recurrent UTIs, and is not the immediate next step after a first febrile UTI without an underlying diagnosis.
- Prophylaxis decisions are made based on imaging results and clinical risk factors, not as a blanket recommendation after initial treatment.
