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ABP Neonatal-Perinatal Medicine study materials
ABP Neonatal-Perinatal Medicine study resources

ABP Neonatal-Perinatal Medicine practice questions

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Question 1Maternal-Fetal Medicine and Antenatal Assessment

Elevated maternal serum alpha-fetoprotein (MSAFP) at 16 weeks is most strongly associated with which fetal condition?

  1. Open neural tube defect Correct answer.
  2. Placental abruption
  3. Trisomy 21
  4. Congenital hypothyroidism

Explanation

Maternal serum AFP rises when fetal cerebrospinal fluid or abdominal contents leak into amniotic fluid, classically with open neural tube defects or ventral wall defects. Trisomy 21 is more often associated with low AFP, and placental abruption does not cause a characteristic AFP elevation.

Question 2Maternal-Fetal Medicine and Antenatal Assessment

At what gestational age is routine screening for gestational diabetes recommended for pregnant people without preexisting diabetes?

  1. 8 to 12 weeks
  2. 24 to 28 weeks Correct answer.
  3. 32 to 36 weeks
  4. 16 to 20 weeks

Explanation

Routine screening for gestational diabetes with a glucose challenge test is recommended at 24 to 28 weeks, when insulin resistance rises. Earlier testing is reserved for people with risk factors or prior gestational diabetes.

Question 3Maternal-Fetal Medicine and Antenatal Assessment

Which antenatal corticosteroid regimen is standard for promoting fetal lung maturity between 24 and 34 weeks?

  1. Dexamethasone 10 mg IM every 12 hours for four doses
  2. Betamethasone 12 mg IM every 24 hours for two doses Correct answer.
  3. Hydrocortisone 100 mg IV every 8 hours for three doses
  4. Prednisone 20 mg orally daily for five days

Explanation

Betamethasone 12 mg IM every 24 hours for two doses is a standard regimen; dexamethasone 6 mg IM every 12 hours for four doses is an alternative. Both accelerate fetal surfactant production and reduce neonatal respiratory morbidity.

Question 4Maternal-Fetal Medicine and Antenatal Assessment

A pregnant person is RhD-negative and unsensitized at 28 weeks' gestation. Which intervention is indicated?

  1. Serial fetal umbilical blood sampling
  2. Anti-D immune globulin Correct answer.
  3. Routine plasmapheresis
  4. No treatment unless bleeding occurs

Explanation

Anti-D immune globulin at 28 weeks prevents alloimmunization in an unsensitized RhD-negative pregnant person; a second dose is given postpartum if the newborn is RhD-positive. Plasmapheresis and fetal blood sampling are not routine prophylaxis.

Question 5Maternal-Fetal Medicine and Antenatal Assessment

Which fetal heart rate baseline is considered normal?

  1. 110 to 160 beats per minute Correct answer.
  2. 180 to 200 beats per minute
  3. 160 to 180 beats per minute
  4. 90 to 110 beats per minute

Explanation

A normal fetal heart rate baseline is 110 to 160 beats per minute. Values below 110 define bradycardia, and values above 160 define tachycardia.

Question 6Maternal-Fetal Medicine and Antenatal Assessment

To reduce the risk of neural tube defects, folic acid supplementation should begin at least how long before conception?

  1. After a positive pregnancy test
  2. 1 week
  3. 6 months
  4. 1 month Correct answer.

Explanation

Folic acid 400 mcg daily should begin at least 1 month before conception to reduce neural tube defects; higher doses are used after a prior affected pregnancy. Starting only after a positive test misses the period of neural tube closure.

Question 7Maternal-Fetal Medicine and Antenatal Assessment

Which history most clearly qualifies a pregnant person for low-dose aspirin prophylaxis for preeclampsia?

  1. Prior preeclampsia requiring preterm delivery Correct answer.
  2. Nulliparity at age 30
  3. Singleton gestation
  4. Mild obesity with BMI 27

Explanation

A prior preeclampsia requiring preterm delivery is a high-risk factor that warrants low-dose aspirin, typically 81 mg daily starting at 12 to 16 weeks. Nulliparity alone, mild obesity, and singleton gestation are not sufficient high-risk criteria by themselves.

Question 8Maternal-Fetal Medicine and Antenatal Assessment

Which finding is an indication for intrapartum antibiotic prophylaxis against early-onset group B streptococcal disease?

  1. Planned cesarean delivery before labor with intact membranes
  2. GBS bacteriuria during the current pregnancy Correct answer.
  3. GBS colonization in a previous pregnancy with negative cultures this pregnancy
  4. Rupture of membranes at term with a negative GBS culture

Explanation

GBS bacteriuria during pregnancy indicates heavy colonization and is an indication for intrapartum prophylaxis regardless of gestational age. Previous colonization with a current negative culture, cesarean before labor, and term rupture with negative culture do not require prophylaxis.

Question 9Maternal-Fetal Medicine and Antenatal Assessment

Magnesium sulfate for fetal neuroprotection is recommended when delivery is anticipated at which gestational age?

  1. 34 to 37 weeks
  2. Less than 28 weeks
  3. 32 to 34 weeks
  4. Less than 32 weeks Correct answer.

Explanation

Magnesium sulfate for fetal neuroprotection is recommended when preterm delivery is anticipated before 32 weeks, typically with a 4-g loading dose and 1 g/h maintenance. It reduces the risk of cerebral palsy.

Question 10Maternal-Fetal Medicine and Antenatal Assessment

In a fetus with early-onset growth restriction, which umbilical artery Doppler finding indicates the greatest risk of acidemia and stillbirth?

  1. Increased end-diastolic flow
  2. Absent or reversed end-diastolic flow Correct answer.
  3. Increased middle cerebral artery pulsatility index
  4. Normal systolic/diastolic ratio

Explanation

Absent or reversed end-diastolic flow in the umbilical artery reflects rising placental vascular resistance and is associated with acidemia and stillbirth in growth-restricted fetuses. Increased end-diastolic flow and normal ratios are reassuring.

Question 11Maternal-Fetal Medicine and Antenatal Assessment

Which statement best describes cell-free DNA screening for fetal aneuploidy?

  1. It detects all clinically significant chromosomal abnormalities.
  2. It is diagnostic and replaces amniocentesis.
  3. A positive result requires diagnostic testing for confirmation. Correct answer.
  4. It is recommended only after 24 weeks' gestation.

Explanation

Cell-free DNA is a screening test with high sensitivity but is not diagnostic; a positive result must be confirmed by amniocentesis or chorionic villus sampling. It does not detect all chromosomal abnormalities.

Question 12Maternal-Fetal Medicine and Antenatal Assessment

Which antibiotic combination is commonly recommended to prolong latency after preterm premature rupture of membranes?

  1. Ampicillin plus erythromycin Correct answer.
  2. Metronidazole alone
  3. Ceftriaxone plus azithromycin
  4. Vancomycin plus gentamicin

Explanation

Ampicillin plus erythromycin, or azithromycin as an alternative, for 7 days is a standard latency antibiotic regimen after preterm premature rupture of membranes. It reduces maternal and neonatal infection and prolongs pregnancy.

Question 13Maternal-Fetal Medicine and Antenatal Assessment

A 32-week pregnant person with placenta previa has a small painless vaginal bleed and is hemodynamically stable. Which is the most appropriate initial management?

  1. Expectant management with corticosteroids and close monitoring Correct answer.
  2. Outpatient management without activity restriction
  3. Immediate cesarean delivery regardless of fetal status
  4. Digital cervical examination to assess dilation

Explanation

In a hemodynamically stable patient with placenta previa and limited bleeding, expectant management with corticosteroids, blood product availability, and close monitoring is appropriate. Digital cervical examination is contraindicated because it can provoke catastrophic hemorrhage.

Question 14Maternal-Fetal Medicine and Antenatal Assessment

Monochorionic diamniotic twins show a deepest vertical pocket of 2 cm in one sac and 10 cm in the other. Which diagnosis is most likely?

  1. Dichorionic twin gestation
  2. Selective fetal growth restriction
  3. Twin anemia-polycythemia sequence
  4. Twin-twin transfusion syndrome Correct answer.

Explanation

Twin-twin transfusion syndrome in monochorionic diamniotic twins is defined by a deepest vertical pocket under 2 cm in the donor sac and over 8 cm in the recipient sac. Twin anemia-polycythemia sequence lacks this oligohydramnios-polyhydramnios sequence.

Question 15Maternal-Fetal Medicine and Antenatal Assessment

Which preconception hemoglobin A1c target is recommended for a pregnant person with type 1 diabetes to minimize congenital malformations?

  1. Less than 6.5% Correct answer.
  2. Less than 5.0%
  3. Less than 10.0%
  4. Less than 8.0%

Explanation

A preconception HbA1c target of less than 6.5% is recommended when achievable without hypoglycemia, because poor glycemic control increases congenital malformations. Targets below 5.0% are generally not required and may increase hypoglycemia risk.

Question 16Maternal-Fetal Medicine and Antenatal Assessment

Which antithyroid medication is preferred during the first trimester of pregnancy?

  1. Propylthiouracil Correct answer.
  2. Methimazole
  3. Radioactive iodine
  4. Levothyroxine

Explanation

Propylthiouracil is preferred during the first trimester because methimazole has been associated with aplasia cutis and esophageal atresia. Levothyroxine treats hypothyroidism, and radioactive iodine is contraindicated in pregnancy.

Question 17Maternal-Fetal Medicine and Antenatal Assessment

A fetal heart rate tracing shows absent baseline variability, recurrent late decelerations, and a sinusoidal pattern. How should this be classified?

  1. Category II
  2. Category I
  3. Normal
  4. Category III Correct answer.

Explanation

A category III tracing includes absent baseline variability with recurrent late decelerations, recurrent variable decelerations, bradycardia, or a sinusoidal pattern. It requires immediate evaluation and intrauterine resuscitation.

Question 18Maternal-Fetal Medicine and Antenatal Assessment

Which finding on transvaginal ultrasound is diagnostic of vasa previa?

  1. A low-lying placenta at 20 weeks
  2. Fetal vessels crossing the internal os over the cervix Correct answer.
  3. Placental edge within 2 cm of the internal os
  4. A succenturiate lobe without vessels

Explanation

Vasa previa is diagnosed when unprotected fetal vessels cross or lie very close to the internal cervical os. These vessels can rupture with membrane rupture, causing rapid fetal exsanguination.

Question 19Maternal-Fetal Medicine and Antenatal Assessment

A pregnant person is RhD-negative with an anti-D titer of 1:32 at 24 weeks. Which is the next best step?

  1. Immediate intrauterine transfusion
  2. Referral for middle cerebral artery peak systolic velocity monitoring Correct answer.
  3. Reassurance with no further testing
  4. Repeat antibody titer in 4 weeks only

Explanation

An anti-D titer at or above the critical threshold, commonly 1:16, indicates a risk of fetal anemia and warrants middle cerebral artery peak systolic velocity monitoring. MCA peak systolic velocity above 1.5 multiples of the median suggests severe anemia and may require transfusion.

Question 20Maternal-Fetal Medicine and Antenatal Assessment

A biophysical profile score is 4 out of 10 at 34 weeks' gestation. Which management is most appropriate?

  1. Arrange delivery after administering antenatal corticosteroids Correct answer.
  2. Repeat the test in 1 week
  3. Reassure and continue routine antenatal care
  4. Perform a contraction stress test and discharge if negative

Explanation

A biophysical profile score of 4 or less is abnormal and generally prompts delivery when the fetus is viable, after antenatal corticosteroids if gestational age permits. Expectant management or discharge is inappropriate.

Question 21Delivery Room Care and Neonatal Resuscitation

A term newborn is born with central cyanosis and poor muscle tone but is breathing spontaneously. According to neonatal resuscitation guidelines, which is the most appropriate initial action in the first 30 seconds?

  1. Perform immediate intubation and tracheal suctioning
  2. Provide warmth, dry the infant, and stimulate breathing Correct answer.
  3. Administer intravenous epinephrine 0.02 mg/kg
  4. Begin chest compressions at a rate of 100 per minute

Explanation

The initial steps for every newborn are warmth, drying, stimulation, and airway positioning. These actions are provided in the first 30 seconds and often prompt spontaneous breathing. Chest compressions, epinephrine, and intubation are reserved for specific indications after effective ventilation has been established.

Question 22Delivery Room Care and Neonatal Resuscitation

A healthy term newborn has Apgar scores recorded at which times during the delivery room course?

  1. At 1 minute and 5 minutes of life Correct answer.
  2. At 2 minutes and 10 minutes of life
  3. At 30 seconds and 3 minutes of life
  4. At 5 minutes and 15 minutes of life

Explanation

The Apgar score is routinely assigned at 1 and 5 minutes after birth. If the 5-minute score remains below 7, additional scores are obtained every 5 minutes up to 20 minutes. The score is not used to guide resuscitation decisions.

Question 23Delivery Room Care and Neonatal Resuscitation

Which approach to airway suctioning is recommended for a vigorous term newborn immediately after birth?

  1. Suction only if airway obstruction is suspected Correct answer.
  2. Suction the oropharynx routinely before drying the infant
  3. Suction the nasopharynx deeply to prevent meconium aspiration
  4. Suction the trachea routinely when meconium is present

Explanation

Routine oropharyngeal or nasopharyngeal suctioning of a vigorous newborn is not recommended because it can cause bradycardia, mucosal injury, and delay initiation of breathing. Suction should be reserved for obvious airway obstruction or when positive pressure ventilation is required. Deep tracheal suction is not routine even with meconium unless the infant is non-vigorous and obstruction is suspected.

Question 24Delivery Room Care and Neonatal Resuscitation

During positive pressure ventilation of a newborn, what rate is recommended?

  1. 20 to 30 breaths per minute
  2. 10 to 20 breaths per minute
  3. 60 to 80 breaths per minute
  4. 40 to 60 breaths per minute Correct answer.

Explanation

Positive pressure ventilation in newborns is delivered at 40 to 60 breaths per minute. This rate supports adequate minute ventilation while allowing sufficient time for expiration. Rates outside this range can impair gas exchange and hemodynamics.

Question 25Delivery Room Care and Neonatal Resuscitation

Where should chest compressions be delivered in a newborn?

  1. Over the xiphoid process at the tip of the sternum
  2. On the upper third of the sternum between the clavicles
  3. On the lower third of the sternum Correct answer.
  4. Over the left fifth intercostal space at the apex

Explanation

Chest compressions are performed on the lower third of the sternum to compress the heart against the spine. The xiphoid process should be avoided because pressure there can injure the liver. The depth is about one-third of the anteroposterior chest diameter.

Question 26Delivery Room Care and Neonatal Resuscitation

Which temperature range is targeted for a newborn in the delivery room to balance warmth and avoid hyperthermia?

  1. 34.0 to 35.0 °C
  2. 36.5 to 37.5 °C Correct answer.
  3. 37.5 to 38.5 °C
  4. 35.0 to 36.0 °C

Explanation

Newborns should be kept at a core temperature of 36.5 to 37.5 °C after birth. This range reduces cold stress and oxygen consumption while avoiding hyperthermia, which can worsen neurological injury. Preterm infants require additional measures such as plastic wrap and a hat.

Question 27Delivery Room Care and Neonatal Resuscitation

A newborn at 30 seconds after birth has a heart rate of 90 bpm, is apneic, and has poor tone. After initial steps, what is the next intervention?

  1. Begin positive pressure ventilation with a face mask Correct answer.
  2. Obtain a blood gas and observe for another minute
  3. Give epinephrine via the umbilical vein
  4. Start chest compressions with 100% oxygen

Explanation

Positive pressure ventilation is indicated when a newborn is apneic, has ineffective breathing, or has a heart rate below 100 bpm after initial steps. Chest compressions are not started until the heart rate remains below 60 bpm despite effective ventilation. Epinephrine and blood gas analysis are later steps.

Question 28Delivery Room Care and Neonatal Resuscitation

For a preterm newborn at 30 weeks' gestation requiring positive pressure ventilation at birth, which initial oxygen concentration is recommended?

  1. 50% oxygen
  2. 40% oxygen
  3. 100% oxygen
  4. 21% to 30% oxygen Correct answer.

Explanation

For preterm newborns below 35 weeks' gestation, positive pressure ventilation is started with 21% to 30% oxygen. Oxygen is then titrated to preductal oxygen saturation targets using pulse oximetry. Term newborns typically begin with 21% oxygen.

Question 29Delivery Room Care and Neonatal Resuscitation

During neonatal CPR with chest compressions and positive pressure ventilation, what compression-to-ventilation ratio should be used?

  1. 5 compressions to 1 ventilation
  2. 15 compressions to 2 ventilations
  3. 3 compressions to 1 ventilation Correct answer.
  4. 30 compressions to 2 ventilations

Explanation

Neonatal chest compressions are coordinated with ventilation in a 3:1 ratio. This provides 90 compressions and 30 breaths per minute. The ratio reflects the priority of ventilation in neonatal resuscitation.

Question 30Delivery Room Care and Neonatal Resuscitation

What is the recommended intravenous dose of epinephrine for a newborn with a heart rate below 60 bpm despite effective ventilation and chest compressions?

  1. 0.02 mg/kg of 1:10,000 solution Correct answer.
  2. 0.5 mg/kg of 1:10,000 solution
  3. 1 mg/kg of 1:10,000 solution
  4. 0.1 mg/kg of 1:10,000 solution

Explanation

The recommended intravenous epinephrine dose is 0.01 to 0.03 mg/kg of the 1:10,000 concentration. This equals 0.1 to 0.3 mL/kg, and 0.02 mg/kg is a commonly used midpoint. The dose may be repeated every 3 to 5 minutes if the heart rate remains below 60 bpm.

Question 31Delivery Room Care and Neonatal Resuscitation

A term newborn is delivered through thick meconium-stained fluid and is non-vigorous with a heart rate of 80 bpm and apnea. What is the recommended initial management?

  1. Suction the mouth and nose vigorously before drying
  2. Intubate immediately and perform tracheal suction
  3. Begin face-mask positive pressure ventilation Correct answer.
  4. Give chest compressions before starting ventilation

Explanation

Current neonatal resuscitation guidance does not recommend routine tracheal intubation and suction for non-vigorous infants born through meconium-stained fluid. Instead, initial steps and positive pressure ventilation are provided as needed. Tracheal suction is reserved for suspected airway obstruction.

Question 32Delivery Room Care and Neonatal Resuscitation

For an uncomplicated term newborn who is breathing well, what cord management is recommended at delivery?

  1. Cord milking before clamping in all term infants
  2. Clamping after 5 minutes in every newborn
  3. Immediate cord clamping within 5 seconds
  4. Delayed clamping for at least 30 to 60 seconds Correct answer.

Explanation

For term and preterm newborns who are breathing and do not require immediate resuscitation, delayed cord clamping for at least 30 to 60 seconds is recommended. This improves transitional circulation and increases iron stores. Immediate clamping is reserved for infants requiring urgent resuscitation.

Question 33Delivery Room Care and Neonatal Resuscitation

Which endotracheal tube internal diameter is appropriate for a newborn weighing approximately 3 kg?

  1. 2.5 mm
  2. 5.0 mm
  3. 4.5 mm
  4. 3.5 mm Correct answer.

Explanation

Endotracheal tube size is estimated by weight and gestation. A 3.0-mm tube is typical for 1 to 2 kg, 3.5 mm for approximately 3 kg, and 2.5 mm for infants under 1 kg. Depth is usually set at three times the tube size in centimeters.

Question 34Delivery Room Care and Neonatal Resuscitation

A newborn at 36 weeks' gestation weighing 2.4 kg needs positive pressure ventilation, but face-mask ventilation is ineffective and intubation attempts have failed. Which device is most appropriate as a rescue airway?

  1. A laryngeal mask airway Correct answer.
  2. A nasal cannula with 2 L/min oxygen
  3. A non-rebreather mask
  4. A 2.5-mm endotracheal tube

Explanation

A laryngeal mask airway can provide rescue ventilation when face-mask ventilation fails and endotracheal intubation is unsuccessful. It is generally used in newborns at least 34 weeks' gestation and about 2000 g. It does not replace intubation when intubation is clearly indicated.

Question 35Delivery Room Care and Neonatal Resuscitation

A newborn has a heart rate of 50 bpm after effective ventilation, compressions, and one dose of epinephrine, and shows signs of hypovolemia with pale skin and weak pulses. What volume expander and dose are recommended?

  1. 10 mL/kg of normal saline over 5 to 10 minutes Correct answer.
  2. 20 mL/kg of 5% dextrose intravenously
  3. 5 mL/kg of packed red blood cells intravenously
  4. 50 mL/kg of lactated Ringer's intravenously rapidly

Explanation

Volume expansion is considered when hypovolemia is suspected and the heart rate remains low despite effective ventilation, compressions, and epinephrine. Normal saline 10 mL/kg or packed red blood cells 10 mL/kg is given intravenously over 5 to 10 minutes. The dose may be repeated based on response.

Question 36Delivery Room Care and Neonatal Resuscitation

At 10 minutes after birth, which preductal oxygen saturation target is recommended for a term newborn receiving respiratory support?

  1. 85% to 95% Correct answer.
  2. 75% to 85%
  3. 65% to 75%
  4. 50% to 60%

Explanation

Preductal oxygen saturation is monitored with a right hand pulse oximeter. At 10 minutes after birth, the target range is 85% to 95%. Lower targets apply in the first minutes of life as transition occurs.

Question 37Delivery Room Care and Neonatal Resuscitation

When intravenous access is unavailable during neonatal resuscitation, what is the recommended endotracheal dose of epinephrine?

  1. 0.1 mg/kg of 1:1,000 solution
  2. 0.5 mg/kg of 1:10,000 solution
  3. 0.05 to 0.1 mg/kg of 1:10,000 solution Correct answer.
  4. 0.01 to 0.03 mg/kg of 1:10,000 solution

Explanation

The endotracheal epinephrine dose is 0.05 to 0.1 mg/kg of the 1:10,000 solution, which is higher than the intravenous dose. Absorption from the trachea is unpredictable, so intravenous access is preferred. The endotracheal route is used only when intravenous access cannot be obtained.

Question 38Delivery Room Care and Neonatal Resuscitation

Which statement about sodium bicarbonate during neonatal resuscitation is correct?

  1. It is recommended for all newborns with heart rate below 100 bpm
  2. It is not routinely recommended and may worsen acidosis Correct answer.
  3. It should be given before epinephrine in prolonged arrest
  4. It is the first-line drug for bradycardia after epinephrine

Explanation

Sodium bicarbonate is not routinely recommended during neonatal resuscitation. It can cause hyperosmolarity, intraventricular hemorrhage, and paradoxical intracellular acidosis. Epinephrine and effective ventilation remain the priority treatments for bradycardia.

Question 39Delivery Room Care and Neonatal Resuscitation

A term newborn at 39 weeks' gestation has a 10-minute Apgar of 3, severe metabolic acidosis on cord gas, and signs of encephalopathy. Which intervention is indicated within the first 6 hours?

  1. Therapeutic hypothermia Correct answer.
  2. Immediate rewarming to 38.5 °C
  3. Exchange transfusion
  4. Prophylactic antibiotics only

Explanation

Therapeutic hypothermia is indicated for newborns at 36 weeks' gestation or more with moderate to severe hypoxic-ischemic encephalopathy. Cooling should begin within 6 hours of birth and be continued for 72 hours. It reduces mortality and neurodevelopmental disability.

Question 40Delivery Room Care and Neonatal Resuscitation

A newborn receives positive pressure ventilation for 30 seconds and chest compressions for 60 seconds. The heart rate is now 70 bpm and the infant remains apneic. What is the next step?

  1. Stop compressions and continue ventilation Correct answer.
  2. Continue compressions and administer epinephrine
  3. Give sodium bicarbonate and continue compressions
  4. Stop ventilation and begin chest compressions

Explanation

Chest compressions are discontinued when the heart rate rises to 60 bpm or higher. Positive pressure ventilation is continued because the infant remains apneic. Epinephrine is not indicated once the heart rate is above 60 bpm.

Question 41Respiratory Disorders of the Newborn

A 28-week preterm infant develops grunting, subcostal retractions, and hypoxemia within the first hours after birth. The primary pathophysiology of respiratory distress syndrome is deficiency of which component?

  1. Pulmonary capillaries
  2. Pulmonary surfactant Correct answer.
  3. Fetal lung fluid
  4. Alveolar macrophages

Explanation

Respiratory distress syndrome results from insufficient surfactant production by immature type II pneumocytes. Low surfactant raises alveolar surface tension, producing progressive atelectasis, a low functional residual capacity, and ventilation-perfusion mismatch.

Question 42Respiratory Disorders of the Newborn

A term infant delivered by elective cesarean section without labor develops tachypnea and mild grunting soon after birth. The chest radiograph shows perihilar streaking and fluid in the minor fissure. What is the underlying mechanism?

  1. Congenital obstruction of the pulmonary lymphatics
  2. Delayed clearance of fetal lung fluid Correct answer.
  3. Right-to-left shunting through a persistent ductus arteriosus
  4. Surfactant deficiency causing alveolar collapse

Explanation

Transient tachypnea of the newborn reflects slow resorption of fetal lung fluid, which is normally driven by thoracic squeeze and catecholamine-mediated epithelial sodium channel activity at birth. Absent labor and cesarean delivery reduce these triggers, so fluid lingers in the interstitium and lymphatics.

Question 43Respiratory Disorders of the Newborn

Which agent is the standard first-line pharmacologic treatment for apnea of prematurity because of its wide therapeutic index and once-daily dosing?

  1. Naloxone
  2. Doxapram
  3. Caffeine citrate Correct answer.
  4. Phenobarbital

Explanation

Caffeine is a methylxanthine that antagonizes adenosine receptors, increasing respiratory center output and diaphragmatic contractility. Its long half-life in neonates allows once-daily dosing with a wide margin of safety compared with other respiratory stimulants.

Question 44Respiratory Disorders of the Newborn

A newborn has excessive drooling, choking and cyanosis with the first feed, and respiratory distress. A radiograph shows a coiled nasogastric tube in the upper esophagus with gas in the stomach. Which diagnosis is most likely?

  1. Tracheoesophageal fistula Correct answer.
  2. Bilateral choanal atresia
  3. Congenital diaphragmatic hernia with pulmonary hypoplasia
  4. Hypertrophic pyloric stenosis

Explanation

The inability to pass a nasogastric tube with coiling in the upper esophagus indicates esophageal atresia, and gas in the stomach confirms a concurrent tracheoesophageal fistula. Feeding produces choking because milk overflows into the airway through the fistula or is regurgitated from the blind pouch.

Question 45Respiratory Disorders of the Newborn

Nasal continuous positive airway pressure is applied to a preterm infant with early respiratory distress. Its main physiologic benefit is which of the following?

  1. Preventing alveolar collapse and maintaining functional residual capacity Correct answer.
  2. Increasing tidal volume by delivering a fixed peak inspiratory pressure
  3. Stimulating surfactant secretion by type II pneumocytes
  4. Lowering pulmonary vascular resistance directly

Explanation

Continuous positive airway pressure splints the airways and alveoli open throughout the respiratory cycle, preserving functional residual capacity and reducing atelectrauma. Improved oxygenation follows from better recruitment and a more favorable ventilation-perfusion match.

Question 46Respiratory Disorders of the Newborn

A ventilated 26-week infant suddenly desaturates and becomes bradycardic. Breath sounds are markedly reduced on the right, the heart sounds are displaced to the left, and the chest radiograph shows a radiolucent right hemithorax without lung markings. What is the most likely cause?

  1. Unilateral pulmonary interstitial emphysema
  2. Tension pneumothorax Correct answer.
  3. Congenital lobar overinflation of the right upper lobe
  4. Right upper lobe atelectasis

Explanation

Sudden decompensation with ipsilateral absent breath sounds, contralateral mediastinal shift, and a lucent hemithorax without vascular markings indicates a tension pneumothorax. Immediate needle decompression followed by tube thoracostomy is required because the shifted mediastinum impairs venous return.

Question 47Respiratory Disorders of the Newborn

A 27-week infant on nasal CPAP with FiO2 0.40 has increasing retractions and a chest radiograph with low lung volumes. Which management step is best supported?

  1. Wait until FiO2 reaches 1.0 before giving surfactant
  2. Give exogenous surfactant using brief intubation or a thin catheter Correct answer.
  3. Give antenatal corticosteroids now to accelerate surfactant release
  4. Increase CPAP to 10 cm H2O and reassess in 6 hours

Explanation

Rising oxygen need and worsening work of breathing on CPAP indicate surfactant failure requiring exogenous surfactant, delivered either by brief intubation (INSURE) or a minimally invasive catheter technique. Early treatment before severe deterioration reduces air leak and the need for prolonged mechanical ventilation.

Question 48Respiratory Disorders of the Newborn

A term infant with severe hypoxemia has echocardiographic evidence of persistent pulmonary hypertension of the newborn. Which finding best supports this diagnosis?

  1. Left-to-right flow across a small patent ductus arteriosus with normal biventricular pressures
  2. Premature closure of the ductus arteriosus with a hypoplastic right ventricle
  3. Bidirectional or right-to-left ductal shunt with systemic-level right ventricular pressure Correct answer.
  4. A structurally normal heart with left ventricular dilation and reduced shortening fraction

Explanation

In persistent pulmonary hypertension, elevated pulmonary vascular resistance raises right ventricular pressure to systemic or suprasystemic levels. The ductus and foramen ovale then show bidirectional or right-to-left shunting, which explains the labile hypoxemia and differential cyanosis.

Question 49Respiratory Disorders of the Newborn

A term infant with echocardiographically confirmed pulmonary hypertension remains hypoxemic despite lung recruitment, sedation, and an FiO2 of 1.0. Which therapy is the appropriate next step?

  1. Hyperventilation to a pH of 7.60
  2. A bolus of intravenous epinephrine
  3. Intravenous nitroprusside
  4. Inhaled nitric oxide Correct answer.

Explanation

Inhaled nitric oxide is a selective pulmonary vasodilator that reaches ventilated alveoli directly, lowering pulmonary vascular resistance without causing systemic hypotension. It is the standard first-line vasodilator for term and late-preterm infants with hypoxemic respiratory failure from pulmonary hypertension.

Question 50Respiratory Disorders of the Newborn

Which statement best defines bronchopulmonary dysplasia in an infant born at 26 weeks' gestation?

  1. Oxygen or respiratory support at 36 weeks' postmenstrual age Correct answer.
  2. Radiographic hyperinflation in a term infant after meconium aspiration
  3. Any oxygen requirement persisting beyond 28 days of life, regardless of gestational age
  4. Cystic lung changes appearing within the first 24 hours after birth in term infants

Explanation

For infants born before 32 weeks, bronchopulmonary dysplasia is defined by the need for oxygen or respiratory support at 36 weeks' postmenstrual age, with severity graded by the level of support required. The definition captures the chronic, evolving lung injury of prematurity rather than an acute radiographic appearance.