A 4-day-old male newborn is brought to the physician for a well-child examination. His mother is concerned that he is losing weight. He was born at 40 weeks' gestation and weighed 2980g (6-lb 9-oz); he currently weighs 2830g (6-lb 4-oz). Pregnancy was uncomplicated. He passed stool and urine 8 and 10 hours after delivery. He has been exclusively breast fed since birth and feeds 11–12 times daily. His mother says she changes 5–6 heavy diapers daily. Examination shows an open and firm anterior fontanelle. Mucous membranes are moist. Capillary refill time is less than 2 seconds. Cardiopulmonary examination shows no abnormalities. Which of the following is the most appropriate next best step in management?
Q42
A 26-year-old G1P0 female who is 39 weeks pregnant presents to the emergency department in labor. She reports following her primary care physician’s recommendations throughout her pregnancy and has not had any complications. During delivery, the baby’s head turtled back into the vaginal canal and did not advance any further. The neonatal intensivist was called for shoulder dystocia and a baby girl was able to be delivered vaginally 6 minutes later. Upon initial assessment, the baby appeared pale throughout, had her arms and legs flexed without active motion, and had some flexion of extremities when stimulated. Her pulse is 120/min and had irregular respirations. What is this baby’s initial APGAR score?
Q43
A 7-year-old girl is brought to the physician because of scant painless bleeding from the vagina 6 hours ago. She has no history of serious illness or trauma. Her older sister had her first period at age 11. The patient is at the 80th percentile for height and 95th percentile for weight and BMI. Examination shows greasy facial skin and sparse axillary hair. Breast development is at Tanner stage 3 and pubic hair development is at Tanner stage 2. The external genitalia appear normal. Serum glucose is 189 mg/dL. Intravenous administration of leuprolide causes an increase in serum luteinizing hormone. Which of the following is the most likely underlying cause of this patient's findings?
Q44
A 19-year-old primigravid woman at 32 weeks' gestation comes to the physician because of a 2-day history of headache and blurred vision. She has had no prenatal care. She is diagnosed with pre-eclampsia. Amniocentesis shows a lecithin-sphingomyelin ratio of 0.7. If delivery is induced at this time, the newborn is most likely to show which of the following findings?
Q45
A 13-month-old boy is brought to the emergency department by his parents 30 minutes after having a 1-minute seizure. He has had a 1-day history of severe diarrhea and fever and 1 episode of vomiting. He has no history of serious illness. His immunization records are not available. He appears restless and cries when picked up from his mother's lap. His temperature is 38.9°C (102°F), pulse is 150/min, respirations are 30/min, and blood pressure is 90/50 mm Hg. Examination shows a distended abdomen. The extremities are cool to the touch, and his capillary refill time is 2–3 seconds. Further evaluation is most likely to show which of the following?
Q46
One week after discharge from the neonatal intensive care unit to a regular pediatric ward, a 1450-g (3-lb 1-oz) male infant has respiratory distress and wheezing. After birth, the patient was intubated and mechanically ventilated for 3 weeks because of hypoxia. He required a 60% fraction of inspired oxygen to achieve adequate oxygen saturation. His temperature is 36.9°C (98.4°F), pulse is 144/min, respirations are 59/min, and blood pressure is 65/35 mm Hg. Physical examination shows labored breathing, intercostal retractions, and crackles at both lung bases. There is bluish discoloration around the lips. An x-ray of the chest shows interspersed areas of atelectasis, granular densities, and hyperinflation. Which of the following is the most likely diagnosis?
Q47
A 7-day-old male infant presents to the pediatrician for weight loss. There is no history of excessive crying, irritability, lethargy, or feeding difficulty. The parents deny any history of fast breathing, bluish discoloration of lips/nails, fever, vomiting, diarrhea, or seizures. He was born at full term by vaginal delivery without any perinatal complications and his birth weight was 3.6 kg (8 lb). Since birth he has been exclusively breastfed and passes urine six to eight times a day. His physical examination, including vital signs, is completely normal. His weight is 3.3 kg (7.3 lb); length and head circumference are normal for his age and sex. Which of the following is the next best step in the management of the infant?
Q48
A 5-year-old patient is brought to the emergency department by his parents for concerning behavior. His parents relate that over the past 3 weeks, he has had multiple episodes of staring into space, lip smacking, and clasping his hands together. The patient has his eyes open during these episode but does not respond to his parents’ voice or his name. These episodes last between 1-2 minutes after which the patient appears to return back to awareness. The patient is confused after these episodes and appears not to know where he is for about 15 minutes. These episodes occur once every few days and the most recent one happened about 10 minutes before the patient arrived to the emergency department. On arrival, the patient is mildly confused and does not know where he is or what recently happened. He is slow to respond to questions and appears tired. Which of the following is the most likely diagnosis in this patient?
Q49
You are counseling a pregnant woman who plans to breast-feed exclusively regarding her newborn's nutritional requirements. The child was born at home and the mother only plans for her newborn to receive vaccinations but no other routine medical care. Which vitamins should be given to the newborn?
Q50
A previously healthy 6-year-old boy is brought to the physician because he has increased facial and axillary hair. There is no family history of serious illness. He is at 95th percentile for height and weight. Examination shows coarse pubic and axillary hair. The penis and left testicle are enlarged. Serum concentrations of human chorionic gonadotropin and alpha-fetoprotein are within the reference range. Which of the following is the most likely cause of these findings?
Growth/Development US Medical PG Practice Questions and MCQs
Question 41: A 4-day-old male newborn is brought to the physician for a well-child examination. His mother is concerned that he is losing weight. He was born at 40 weeks' gestation and weighed 2980g (6-lb 9-oz); he currently weighs 2830g (6-lb 4-oz). Pregnancy was uncomplicated. He passed stool and urine 8 and 10 hours after delivery. He has been exclusively breast fed since birth and feeds 11–12 times daily. His mother says she changes 5–6 heavy diapers daily. Examination shows an open and firm anterior fontanelle. Mucous membranes are moist. Capillary refill time is less than 2 seconds. Cardiopulmonary examination shows no abnormalities. Which of the following is the most appropriate next best step in management?
A. Continue breastfeeding (Correct Answer)
B. Add rice based cereal
C. Add cow milk based formula
D. Serum creatinine and urea nitrogen
E. Switch to soy-based formula
Explanation: ***Continue breastfeeding***
- A 4-day-old newborn losing less than 7% of birth weight, with good feeding frequency, adequate wet diapers, and normal physical examination findings, is considered typical for **physiological weight loss** in breastfed infants.
- The infant's current weight of 2830g is within the expected range, as healthy full-term newborns may lose up to 7-10% of their birth weight in the first few days, and his weight loss is only about 5%.
*Add rice based cereal*
- **Solid foods**, including rice cereal, should not be introduced before 4-6 months of age due to the immaturity of the infant's digestive system and potential for choking.
- Introducing solids too early can interfere with nutrient absorption from breast milk and increase the risk of allergies.
*Add cow milk based formula*
- Supplementing with formula is unnecessary in a healthy, breastfed infant exhibiting normal physiological weight loss and adequate feeding cues.
- Early introduction of formula can interfere with **successful breastfeeding establishment** and alter the infant's gut microbiome.
*Serum creatinine and urea nitrogen*
- These tests are used to assess **renal function** and are not indicated here, as the infant shows no signs of renal impairment (e.g., adequate urine output, moist mucous membranes).
- The physical examination findings and feeding pattern suggest a healthy newborn, not one requiring investigation for kidney issues.
*Switch to soy-based formula*
- Switching to any formula is unwarranted given the normal weight loss and breastfeeding progress, and specifically, soy-based formula is not routinely recommended for healthy infants.
- Soy formula is often reserved for infants with **cow's milk protein allergy** or **galactosemia**, neither of which is suggested by this clinical picture.
Question 42: A 26-year-old G1P0 female who is 39 weeks pregnant presents to the emergency department in labor. She reports following her primary care physician’s recommendations throughout her pregnancy and has not had any complications. During delivery, the baby’s head turtled back into the vaginal canal and did not advance any further. The neonatal intensivist was called for shoulder dystocia and a baby girl was able to be delivered vaginally 6 minutes later. Upon initial assessment, the baby appeared pale throughout, had her arms and legs flexed without active motion, and had some flexion of extremities when stimulated. Her pulse is 120/min and had irregular respirations. What is this baby’s initial APGAR score?
A. 5 (Correct Answer)
B. 6
C. 7
D. 4
E. 3
Explanation: ***5***
- The APGAR score is calculated based on five criteria: **Appearance**, **Pulse**, **Grimace**, **Activity**, and **Respiration**.
- This baby's score is calculated as follows: **Appearance** (pale all over) = 0, **Pulse** (120/min) = 2, **Grimace** (some flexion of extremities with stimulation) = 1, **Activity** (arms and legs flexed without active motion) = 1, and **Respiration** (irregular) = 1.
- Total score: 0 + 2 + 1 + 1 + 1 = **5 points**
- A score of 5 indicates **moderate neonatal compromise** requiring close monitoring and possible intervention.
*4*
- A score of 4 would indicate more severe compromise, such as absent respirations (0 points) rather than irregular respirations (1 point).
- This baby has irregular respirations present, which earns 1 point, not 0 points.
*6*
- A score of 6 would require improvement in at least one category, such as **acrocyanosis** (blue extremities but pink body = 1 point for appearance) instead of pallor throughout.
- This baby's complete pallor limits the score to 5.
*7*
- A score of 7 or higher is generally considered reassuring and indicates a **healthy transition** from intrauterine to extrauterine life.
- This baby's concerning signs, including **complete pallor**, **irregular respirations**, and **poor muscle tone**, are inconsistent with a score of 7.
*3*
- A score of 3 would indicate severe depression with findings such as **heart rate less than 100 bpm**, completely absent reflexes, or flaccid muscle tone.
- This baby has a reassuring pulse of 120/min (2 points), some reflex response (1 point), and some muscle tone (1 point), making the total score higher than 3.
Question 43: A 7-year-old girl is brought to the physician because of scant painless bleeding from the vagina 6 hours ago. She has no history of serious illness or trauma. Her older sister had her first period at age 11. The patient is at the 80th percentile for height and 95th percentile for weight and BMI. Examination shows greasy facial skin and sparse axillary hair. Breast development is at Tanner stage 3 and pubic hair development is at Tanner stage 2. The external genitalia appear normal. Serum glucose is 189 mg/dL. Intravenous administration of leuprolide causes an increase in serum luteinizing hormone. Which of the following is the most likely underlying cause of this patient's findings?
A. Overproduction of adrenal cortisol
B. Ectopic hormone production
C. Pulsatile GnRH release (Correct Answer)
D. Compensatory hyperinsulinemia
E. Deficiency of thyroid hormones
Explanation: ***Pulsatile GnRH release***
- The combination of **precocious puberty** (Tanner stage 3 breasts, sparse axillary hair, vaginal bleeding at age 7), **insulin resistance** (serum glucose 189 mg/dL in a 7-year-old, high BMI), and a **positive leuprolide stimulation test** (increase in LH) points to central precocious puberty driven by pulsatile GnRH release.
- **Obesity** can contribute to earlier onset of puberty, and the elevated LH response to leuprolide confirms a gonadotropin-dependent (central) cause.
*Overproduction of adrenal cortisol*
- **Adrenal cortisol overproduction** (Cushing's syndrome) would typically present with central obesity, moon facies, striae, and possibly virilization, rather than the specific pubertal signs and GnRH-dependent LH response seen here.
- While it can cause some metabolic derangements, it does not directly lead to **gonadotropin-dependent precocious puberty**.
*Ectopic hormone production*
- **Ectopic hormone production** (e.g., from an ovarian tumor or adrenal tumor) would typically cause gonadotropin-independent precocious puberty, meaning the leuprolide test would likely show no or minimal LH response.
- Given the patient's **positive leuprolide test**, ectopic production is less likely as the primary cause of her puberty.
*Compensatory hyperinsulinemia*
- While the patient's elevated glucose and high BMI suggest **insulin resistance** leading to compensatory hyperinsulinemia, this is a metabolic consequence often associated with obesity and earlier puberty, not the primary underlying cause of the precocious puberty itself.
- It would not explain the **pulsatile GnRH release** or the positive leuprolide test.
*Deficiency of thyroid hormones*
- **Hypothyroidism** can cause delayed puberty, not precocious puberty. In rare cases, severe, long-standing hypothyroidism can lead to precocious puberty (Van Wyk-Grumbach syndrome), but this is typically associated with very high TSH and enlarged pituitary, and not the primary symptoms presented.
- The patient's clinical picture and the **positive leuprolide test** do not align with thyroid deficiency as the underlying cause.
Question 44: A 19-year-old primigravid woman at 32 weeks' gestation comes to the physician because of a 2-day history of headache and blurred vision. She has had no prenatal care. She is diagnosed with pre-eclampsia. Amniocentesis shows a lecithin-sphingomyelin ratio of 0.7. If delivery is induced at this time, the newborn is most likely to show which of the following findings?
A. Increased lung compliance
B. Increased diffusion capacity for carbon monoxide
C. Decreased right ventricular afterload
D. Increased anatomical dead space
E. Decreased functional residual capacity (Correct Answer)
Explanation: ***Decreased functional residual capacity***
- A **lecithin-sphingomyelin (L/S) ratio of 0.7** indicates significant **fetal lung immaturity**, as a ratio less than 1.5-2.0 suggests inadequate surfactant production.
- Inadequate surfactant leads to **alveolar collapse**, reducing the amount of air remaining in the lungs after normal exhalation (**functional residual capacity**), and increasing the risk of **respiratory distress syndrome (RDS)**.
*Increased lung compliance*
- **Lung compliance** is typically **decreased** in newborns with **respiratory distress syndrome** due to collapsed alveoli and stiff lungs from surfactant deficiency.
- Surfactant's role is to reduce surface tension, thereby increasing compliance and preventing alveolar collapse.
*Increased diffusion capacity for carbon monoxide*
- **Diffusion capacity** would be **reduced** due to thickened alveolar membranes, decreased surface area for gas exchange, and increased shunting from atelectasis in immature lungs.
- **Respiratory distress syndrome** impairs gas exchange, including the diffusion of gases like carbon monoxide.
*Decreased right ventricular afterload*
- **Pulmonary hypertension** and **increased right ventricular afterload** are common in newborns with severe respiratory distress due to **hypoxia** and **acidosis** causing pulmonary vasoconstriction.
- This can lead to persistent **fetal circulation** if the pulmonary vascular resistance remains high, resulting in right-to-left shunting.
*Increased anatomical dead space*
- **Anatomical dead space** relates to the conducting airways and is generally **fixed** for a given lung size and development. It is not directly increased by surfactant deficiency.
- The primary issue with **surfactant deficiency** is alveolar collapse, which affects **alveolar dead space** (where gas exchange should occur but doesn't), rather than anatomical dead space.
Question 45: A 13-month-old boy is brought to the emergency department by his parents 30 minutes after having a 1-minute seizure. He has had a 1-day history of severe diarrhea and fever and 1 episode of vomiting. He has no history of serious illness. His immunization records are not available. He appears restless and cries when picked up from his mother's lap. His temperature is 38.9°C (102°F), pulse is 150/min, respirations are 30/min, and blood pressure is 90/50 mm Hg. Examination shows a distended abdomen. The extremities are cool to the touch, and his capillary refill time is 2–3 seconds. Further evaluation is most likely to show which of the following?
A. Hyperkalemia
B. Kussmaul breathing
C. Sunken anterior fontanelle (Correct Answer)
D. Increased serum bicarbonate levels
E. Retinal hemorrhages
Explanation: ***Sunken anterior fontanelle***
- The child presents with signs of **moderate dehydration**, including a 1-day history of diarrhea and fever, restlessness, cool extremities, tachycardia (pulse 150/min), and delayed capillary refill of 2-3 seconds (normal is <2 seconds).
- A **sunken fontanelle** is a classic sign of moderate to severe dehydration in infants. While the anterior fontanelle typically closes between 9-18 months (mean ~14 months), at 13 months it is often still open and would be sunken in the setting of significant dehydration.
- Other signs of dehydration present include tachycardia, cool extremities, and delayed capillary refill, all consistent with intravascular volume depletion.
*Hyperkalemia*
- **Hyperkalemia** is typically associated with conditions like **renal failure** or certain metabolic derangements, which are not suggested by the clinical picture.
- This child is more likely to develop **hypokalemia** due to gastrointestinal fluid losses from diarrhea and vomiting, as potassium is lost in these fluids.
*Kussmaul breathing*
- **Kussmaul breathing** is deep, labored breathing associated with severe metabolic acidosis, characteristic of conditions like **diabetic ketoacidosis**.
- While severe dehydration can lead to metabolic acidosis (from lactic acidosis and bicarbonate loss), this child's respiratory rate of 30/min is elevated but not showing the characteristic deep, labored pattern of Kussmaul respirations.
*Increased serum bicarbonate levels*
- **Increased serum bicarbonate levels** would indicate metabolic alkalosis, which is not expected with severe diarrhea.
- The child is likely experiencing **metabolic acidosis** due to bicarbonate loss through diarrhea, poor perfusion leading to lactic acid production, and ketosis from poor oral intake. This would result in **decreased serum bicarbonate**.
*Retinal hemorrhages*
- **Retinal hemorrhages** are highly suggestive of **abusive head trauma (shaken baby syndrome)**, which is not indicated by the clinical history provided.
- The child's symptoms are fully explained by acute gastroenteritis leading to dehydration and a febrile seizure, with no other signs suggesting trauma.
Question 46: One week after discharge from the neonatal intensive care unit to a regular pediatric ward, a 1450-g (3-lb 1-oz) male infant has respiratory distress and wheezing. After birth, the patient was intubated and mechanically ventilated for 3 weeks because of hypoxia. He required a 60% fraction of inspired oxygen to achieve adequate oxygen saturation. His temperature is 36.9°C (98.4°F), pulse is 144/min, respirations are 59/min, and blood pressure is 65/35 mm Hg. Physical examination shows labored breathing, intercostal retractions, and crackles at both lung bases. There is bluish discoloration around the lips. An x-ray of the chest shows interspersed areas of atelectasis, granular densities, and hyperinflation. Which of the following is the most likely diagnosis?
A. Meconium aspiration syndrome
B. Bronchiolitis obliterans
C. Bronchopulmonary dysplasia (Correct Answer)
D. Neonatal pneumonia
E. Pulmonary hypoplasia
Explanation: ***Bronchopulmonary dysplasia***
- This infant's history of **prematurity** (1450g), prolonged mechanical ventilation, and high oxygen requirement for 3 weeks, followed by persistent respiratory distress, wheezing, and characteristic chest X-ray findings (atelectasis, granular densities, hyperinflation), is classic for **bronchopulmonary dysplasia (BPD)**.
- BPD is a chronic lung disease of infancy, primarily affecting premature neonates who have been exposed to **prolonged oxygen therapy** and **mechanical ventilation**, leading to inflammation and abnormal lung development.
*Meconium aspiration syndrome*
- **Meconium aspiration syndrome** occurs when a fetus inhales meconium into the lungs, typically seen in term or post-term infants, not in a *preterm* infant who has been hospitalized for weeks.
- Symptoms usually present *at birth* and involve severe respiratory distress, often with barrel chest and coarse crackles, but not typically a chronic condition developing weeks after initial stabilization.
*Bronchiolitis obliterans*
- **Bronchiolitis obliterans** is a rare, severe obstructive lung disease characterized by fibrous obliteration of the small airways, often following a severe respiratory infection or exposure to toxins.
- While it can cause wheezing and respiratory distress, the history of *prematurity, prolonged ventilation*, and onset *weeks after birth with specific X-ray findings* is more indicative of BPD.
*Neonatal pneumonia*
- **Neonatal pneumonia** would typically present with acute respiratory distress, fever (though neonates can be *hypothermic*), and signs of infection, often within the first days or week of life.
- While the infant is having respiratory distress, the *chronic nature*, history of *prolonged ventilation*, and absence of clear acute infectious signs make pneumonia less likely as the primary diagnosis.
*Pulmonary hypoplasia*
- **Pulmonary hypoplasia** is an *underdevelopment* of the lungs, usually diagnosed *in utero* or immediately *at birth*, often associated with conditions like congenital diaphragmatic hernia or prolonged oligohydramnios.
- The infant's initial stabilization and subsequent development of chronic lung issues weeks later do not align with a condition involving primary underdevelopment of lung tissue.
Question 47: A 7-day-old male infant presents to the pediatrician for weight loss. There is no history of excessive crying, irritability, lethargy, or feeding difficulty. The parents deny any history of fast breathing, bluish discoloration of lips/nails, fever, vomiting, diarrhea, or seizures. He was born at full term by vaginal delivery without any perinatal complications and his birth weight was 3.6 kg (8 lb). Since birth he has been exclusively breastfed and passes urine six to eight times a day. His physical examination, including vital signs, is completely normal. His weight is 3.3 kg (7.3 lb); length and head circumference are normal for his age and sex. Which of the following is the next best step in the management of the infant?
A. Reassurance of parents (Correct Answer)
B. Evaluation of the mother for malnutrition
C. Admission of the infant in the NICU to treat with empiric intravenous antibiotics
D. Emphasize the need to clothe the infant warmly to prevent hypothermia
E. Supplementation of breastfeeding with an appropriate infant formula
Explanation: ***Reassurance of parents***
- A **weight loss of 8.3%** (300g from 3.6kg) is within the expected range for a 7-day-old exclusively breastfed infant, which can be up to 7-10% in the first week.
- The infant's normal physical exam, good urine output, and lack of other symptoms suggest **adequate feeding** and overall well-being.
*Evaluation of the mother for malnutrition*
- The mother's nutritional status is not directly indicative of the infant's weight loss within the normal physiological range in this scenario.
- There is no information to suggest the mother is malnourished or that it would directly impact the quality or quantity of breast milk to cause pathological weight loss.
*Admission of the infant in the NICU to treat with empiric intravenous antibiotics*
- This is an overly aggressive intervention as there are **no signs or symptoms of infection** (e.g., fever, lethargy, poor feeding) and the infant appears well.
- Empiric antibiotics are not warranted in an otherwise healthy, full-term infant with normal physiological weight loss.
*Emphasize the need to clothe the infant warmly to prevent hypothermia*
- The infant's **vital signs are normal**, indicating no hypothermia, and there is no clinical evidence to support this as a primary concern.
- While maintaining warmth is important, it is not the next best step for addressing this specific presentation of physiological weight loss.
*Supplementation of breastfeeding with an appropriate infant formula*
- Supplementation is typically not needed for physiological weight loss in an otherwise healthy, exclusively breastfed infant with **adequate urine output** and no signs of dehydration.
- Encouraging continued exclusive breastfeeding and providing support for proper latch and feeding techniques would be more appropriate if there were concerns about inadequate milk intake.
Question 48: A 5-year-old patient is brought to the emergency department by his parents for concerning behavior. His parents relate that over the past 3 weeks, he has had multiple episodes of staring into space, lip smacking, and clasping his hands together. The patient has his eyes open during these episode but does not respond to his parents’ voice or his name. These episodes last between 1-2 minutes after which the patient appears to return back to awareness. The patient is confused after these episodes and appears not to know where he is for about 15 minutes. These episodes occur once every few days and the most recent one happened about 10 minutes before the patient arrived to the emergency department. On arrival, the patient is mildly confused and does not know where he is or what recently happened. He is slow to respond to questions and appears tired. Which of the following is the most likely diagnosis in this patient?
A. Focal impaired awareness seizure (Correct Answer)
B. Absence seizure
C. Simple partial seizure
D. Generalized tonic-clonic seizure
E. Syncopal episodes
Explanation: ***Focal impaired awareness seizure***
- This patient's symptoms, including **staring**, **automatisms** (lip smacking, hand clasping), **impaired awareness**, and **post-ictal confusion** lasting 15 minutes, are classic for a focal impaired awareness seizure (formerly called complex partial seizure).
- The episodes originate from a **focal area** of the brain and cause alteration in consciousness with motor automatisms, consistent with the 2017 ILAE classification.
- The prolonged post-ictal confusion and duration of 1-2 minutes help distinguish this from absence seizures.
*Absence seizure*
- Absence seizures are characterized by **brief, sudden lapses of consciousness** (typically 5-10 seconds) with staring and **abrupt return to baseline** without post-ictal confusion.
- They usually do not involve complex automatisms like lip smacking or hand clasping, nor do they result in prolonged confusion.
- More common in younger children (4-8 years) but episodes are much shorter.
*Simple partial seizure*
- A simple partial seizure (now called focal aware seizure) involves **focal neurological symptoms** without any impairment of consciousness or awareness.
- The patient would be fully aware and able to respond during the entire episode, which is not the case here given the impaired responsiveness.
*Generalized tonic-clonic seizure*
- Generalized tonic-clonic seizures involve loss of consciousness with **tonic (stiffening)** and **clonic (jerking)** phases affecting the entire body.
- While they do cause significant post-ictal confusion, the absence of generalized motor activity (convulsions) makes this diagnosis unlikely.
- The patient maintains eyes open and has subtle automatisms rather than violent shaking movements.
*Syncopal episodes*
- **Syncope** is a temporary loss of consciousness due to reduced blood flow to the brain, usually triggered by specific events (e.g., pain, dehydration) with rapid and complete recovery.
- The **automatisms**, preserved eyes-open state, prolonged post-ictal confusion, and lack of precipitating factors are all inconsistent with syncope.
- Syncopal episodes typically last seconds, not 1-2 minutes.
Question 49: You are counseling a pregnant woman who plans to breast-feed exclusively regarding her newborn's nutritional requirements. The child was born at home and the mother only plans for her newborn to receive vaccinations but no other routine medical care. Which vitamins should be given to the newborn?
A. Vitamin B6
B. Vitamin K and Vitamin D (Correct Answer)
C. Vitamin K
D. Folic acid
E. Vitamin D
Explanation: ***Vitamin K and Vitamin D***
- All newborns should receive a prophylactic dose of **Vitamin K** to prevent **Vitamin K Deficiency Bleeding (VKDB)**, as placental transfer is poor and breast milk contains low levels.
- Breastfed infants, especially those exclusively breastfed, require **Vitamin D** supplementation (400 IU daily) to prevent **rickets**, as breast milk Vitamin D levels are often insufficient.
*Vitamin B6*
- While essential for development, **Vitamin B6** supplementation is not routinely recommended for all healthy newborns, especially those exclusively breastfed by a healthy mother.
- Deficiency in newborns is rare and typically associated with specific metabolic disorders or maternal malnutrition, which are not suggested here.
*Vitamin K*
- While **Vitamin K** is critically important for all newborns, it is only one of the essential vitamins needed for breastfed infants.
- Exclusive breastfeeding also necessitates **Vitamin D** supplementation, making this option incomplete.
*Folic acid*
- **Folic acid** (Vitamin B9) is crucial during pregnancy for preventing neural tube defects and is found in adequate amounts in breast milk for a healthy full-term infant.
- Routine supplementation of folic acid is not recommended for healthy newborns, as deficiency is rare.
*Vitamin D*
- While **Vitamin D** supplementation is essential for exclusively breastfed infants, this option is incomplete as it misses the critical need for **Vitamin K** prophylaxis at birth.
- Both vitamins are critical for newborn health in this scenario.
Question 50: A previously healthy 6-year-old boy is brought to the physician because he has increased facial and axillary hair. There is no family history of serious illness. He is at 95th percentile for height and weight. Examination shows coarse pubic and axillary hair. The penis and left testicle are enlarged. Serum concentrations of human chorionic gonadotropin and alpha-fetoprotein are within the reference range. Which of the following is the most likely cause of these findings?
A. Sertoli cell tumor
B. Seminoma
C. Leydig cell tumor (Correct Answer)
D. Lymphoma
E. Choriocarcinoma
Explanation: ***Leydig cell tumor***
- The boy's **precocious puberty** symptoms, including increased facial/axillary hair and an enlarged penis and testicle, are consistent with excessive **androgen production**.
- **Leydig cells** are the primary source of testosterone in the testes, and a tumor can cause autonomous androgen secretion, leading to virilization.
*Sertoli cell tumor*
- While Sertoli cell tumors can occur in children, they more commonly present with **feminization** due to estrogen production, such as gynecomastia, or with a palpable mass.
- They are less likely to cause precocious virilization; this patient's enlarged testicle and penis with marked virilization are more characteristic of testosterone-secreting tumors.
*Seminoma*
- **Seminomas** are malignant germ cell tumors that typically affect adult males aged 30-50 and are rare in young children.
- They are unlikely to cause precocious puberty symptoms as directly as a Leydig cell tumor; they often present as a painless testicular mass and may produce **hCG** or **AFP** in some cases.
*Lymphoma*
- Testicular lymphoma is a rare form of non-Hodgkin lymphoma, primarily affecting older men, and is exceedingly rare in children.
- It does not typically cause **endocrine symptoms** like precocious puberty; it would present as a rapidly growing testicular mass.
*Choriocarcinoma*
- **Choriocarcinomas** are aggressive germ cell tumors that produce high levels of **human chorionic gonadotropin (hCG)**.
- While hCG can stimulate Leydig cells to produce testosterone and cause precocious puberty, the serum hCG concentration in this patient is within the reference range, making choriocarcinoma unlikely.
