Neonatology

Question 1

Excessive hyperthermia from prolonged use of hot tubs during pregnancy increases the risk of what congenital abnormality?

Answer 1

Neural Tube Defects

Extensive hyperthermia for prolonged periods during days 14–30 after conception increases the risk of this abnormality.

Question 2

What is the definition of large for gestational age (LGA)?

Answer 2

Birth Weight > 90^th Percentile

Disproportionate measurements are often a cause for concern; an LGA baby due to gestational diabetes is at risk of hypoglycemia.

Question 3

What is one of the most frequent abnormalities in infants with a single umbilical artery?

Answer 3

Trisomy 18

Congenital abnormalities are present in up to 30% of infants with a single umbilical artery; many are stillborn or die soon after birth. Trisomy 18 is one of the most frequent abnormalities. Cardiac and urogenital abnormalities are also associated with single umbilical arteries.

Question 4

A 1-week-old infant currently in the NICU with a history of being born at 28-weeks-gestation presents with:

• Abdominal distention
• Feeding difficulties
• Heme-positive stool
• Plain abdominal film showing gas accumulation in the sub mucosa of the bowel wall

What is the diagnosis?

Answer 4

Necrotizing Enterocolitis (NEC)

NEC is an inflammatory lesion of the bowel that is mainly seen in preterm infants. (It is the most common intestinal emergency seen in this age group.) The listed symptoms can progress to erythema and cellulitis of the abdominal wall, intestinal gangrene with perforation, and/or peritonitis. Bloody stools are seen in ~ 25% of cases. Most commonly, the distal ileum and proximal colon are affected.

Question 5

What scalp pH value should be considered abnormal and indicates need for immediate delivery?

Answer 5

pH < 7.20

Normal fetal scalp blood pH is > 7.25. A scalp pH of 7.20–7.25 is considered suspicious; it should be repeated after 15–30 minutes and assessed in conjunction with the current fetal heart rate pattern and progression of labor.

Question 6

A 3-day-old girl presents with history of whitish vaginal discharge since birth that is now blood-tinged. What is the most likely diagnosis?

Answer 6

Withdrawal of Maternal Hormones (Normal)

Whitish vaginal discharge is common in newborn girls and can persist for up to 2 months. On occasion, the discharge can be tinged with blood due to withdrawal of maternal hormones. This is normal, and no workup is required.

Question 7

What is the most common umbilical abnormality?

Answer 7

Having Only 1 Artery

40% of these infants die or have a major congenital anomaly; trisomy 18 is one of the most frequent.

Question 8

You are observing the fetal heart rate (FHR) monitor. You have noticed that now at the beginning of the contraction peak, the FHR falls, with the return of the FHR only after the contraction has ended. What is this describing, and how should you react?

Answer 8

Late Decels and Check Fetal pH

Late decelerations are a fall in FHR—typically at the beginning or after the peak of the uterine contraction—with the return of the FHR only after the contraction has ended. All late decelerations are considered potentially ominous. If persistent, evaluate further with a measurement of fetal pH.

Question 9

A newborn presents with:

• Firm, fluctuant swelling over the scalp
• Swelling extends to the front of the ears, and the ears are pushed out laterally

What is the most likely diagnosis?

Answer 9

Subgaleal Hemorrhage

Subgaleal hemorrhage results from bleeding behind the scalp aponeurotica. Bleeding can be significant, placing the infant at risk for hypotension, hyperbilirubinemia, and/or a consumptive coagulopathy due to massive blood loss. Hemophilia sometimes first presents with a subgaleal hemorrhage.

Question 10

• Stimulates α-adrenergic receptors
• Enhances cardiac contractility
• Constricts the peripheral circulation
• Has β-adrenergic effects on the receptors of the heart
• Increases rate and effectiveness of cardiac contraction

What neonatal resuscitation drug has these effects?

Answer 10

Epinephrine

Be sure to know the effects of epinephrine on the different receptors and parts of the circulatory system.

Question 11

Evaluate the APGAR score for this newborn at 1 minute:

• Heart rate: 120 bpm
• Respiration: crying
• Muscle tone: active motion
• Reflex irritability: grimace
• Color: body pink, blue limbs

Answer 11

APGAR score of 8

The infant gets 2 points each for the heart rate, respiration, and muscle tone; 1 point each for reflex irritability and color. Therefore, the total score is 8. Exam questions may still ask you to calculate Apgar scores, so be familiar with the system.

Question 12

A term infant in the delivery room presents with:

• Tachypnea
• Differential cyanosis (greater oxygen saturation in the upper body compared to the lower body)
• Tricuspid regurgitation murmur (harsh systolic murmur at the left lower sternal border)
• Loud, narrowly split 2^nd heart sound (P2)

What is the most likely diagnosis?

Answer 12

Persistent Pulmonary Hypertension of the Newborn (PPHN)

PPHN occurs when pulmonary vascular resistance remains elevated after birth, causing pulmonary-to-systemic (right-to-left) shunting of blood via fetal circulatory pathways, leading to severe hypoxia. It is not a specific disease but a syndrome that can be idiopathic or due to a number of causes, including meconium aspiration, sepsis, pulmonary hypoplasia, and others. Differential cyanosis is classic, due to the right-to-left ductus arteriosus shunting.

Question 13

What is the definition of very low birth weight (VLBW)?

Answer 13

Birth Weight < 1,500 grams

An infant with a birth weight of < 1,500 grams, regardless of gestational age, is considered VLBW. Overall survival rates have improved to 90% for VLBW infants

Question 14

What congenital malformations are associated with taking thalidomide during pregnancy?

Answer 14

Missing Arms and/or Legs and Ear Malformations with Deafness

Thalidomide was one of the 1st drugs identified as a human teratogen. It has a 20% risk of causing limb defects in fetuses if used between 34 and 50 days of gestation.

Question 15

A newborn presents after a difficult delivery with:

• Paralysis of the right shoulder and arm
• Right arm is held alongside the body in internal rotation (“waiter’s tip” position).

What is the diagnosis?

Answer 15

Erb Paralysis

It occurs when there is significant lateral traction during delivery, resulting in damage to the upper part of the brachial plexus - particularly the 5^th and 6^th cervical roots. This results in paralysis of the shoulder and arm. Most resolve spontaneously.

Question 16

What fetal heart rate defines “fetal tachycardia”?

Answer 16

Fetal Heart Rate > 160 bpm

Fetal tachycardia is considered a Category 2 FHR monitoring pattern (indeterminate). It is defined as mild at 160–180 bpm and severe when > 180 bpm.

Question 17

A newborn presents with:

• Bowel sounds in the chest
• Scaphoid abdomen
• Displaced point of maximal cardiac impulse

What is the most likely diagnosis?

Answer 17

Diaphragmatic Hernia

Diaphragmatic hernia is an example of an intrathoracic mass that causes one side of the chest to move less than the other. The majority (80–85%) of congenital diaphragmatic hernias are on the left side of the chest. The findings listed here should steer you to this diagnosis, especially hearing bowel sounds in the chest cavity.

Question 18

A young woman with a history of chronic cocaine abuse presents to the prenatal clinic for evaluation.

Identify the main potential risk factor for the infant.

Answer 18

Premature Delivery

Cocaine use during pregnancy also increases the risk of miscarriage and stillbirth. If used near delivery, cocaine can increase the risk of placental abruption and intracranial hemorrhage. Infants born to chronic users during pregnancy are frequently jittery, irritable, and tremulous and have muscle rigidity.

Question 19

An infant is found to have microcolon, also known as neonatal small left colon syndrome.

What diagnosis does the mother likely have?

Answer 19

Diabetes Mellitus

Congenital anomalies occur 2–4 times more frequently in infants of diabetic mothers. Neonatal small left colon syndrome is one congenital anomaly that is associated with maternal DM. The increased risk of these anomalies in infants of diabetic mothers is likely due to poor diabetes control before conception and during early pregnancy, when fetal organogenesis is occurring.

Question 20

A 12-year-old infant presents with:

• Wide persistent posterior fontanelle
• Umbilical hernia
• Jaundice

What is the most likely diagnosis?

Answer 20

Hypothyroidism

Don’t forget that persistent posterior fontanelle is also associated with hydrocephalus and rickets.

Question 21

A newborn presents with the following:

• Coloboma
• Heart disease
• Choanal atresia
• Growth retardation and development
• Genital anomalies
• Ear anomalies

What syndrome does this newborn likely have?

Answer 21

CHARGE Syndrome

CHARGE syndrome is associated with the listed findings (in fact, the name “CHARGE” is an acronym of those findings). Note that if you see coloboma and atresia choanae, start looking for the other abnormalities that are part of CHARGE syndrome.

Question 22

Shortly after delivery, an infant shows respiratory distress, including:

• Tachypnea
• Intercostal restractions
• End-expiratory grunting
• Cyanosis

Physical examination findings are:

• Meconium staining of the skin and nails
• Barrel-shaped chest
• Coarse breath sounds

What is the most likely diagnosis?

Answer 22

Meconium Aspiration Syndrome (MAS)

Meconium aspiration remains one of the most common causes of respiratory failure in full-term newborns. Mortality rate is 4–5% but has decreased considerably with the advent of more sophisticated modes of ventilation along with inhaled nitric oxide therapy. Suctioning of meconium at birth is no longer recommended, even in the nonvigorous newborn. Clear secretions using a bulb syringe or large-bore suction catheter followed by routine resuscitation steps of drying, stimulating, and administering oxygen as needed.

Question 23

A newborn presents with:

• Lethargy
• Hypotonia
• Tremors
• Sweating

What lab abnormality is most likely?

Answer 23

Hypoglycemia

Intervention for hypoglycemia is generally recommended in all neonates with a plasma glucose concentration < 40 mg/dL during the first 24 hours of life and < 50 mg/dL after 24 hours of life. In addition to the listed findings, infants can present with frank seizures and cyanosis. Hypoglycemia is much more common during the first 24 hours of life in infants born to diabetic mothers (25–50% incidence).

Question 24

At a newborn’s examination, you note edema and blood over the parietal bones, and it does not appear to cross suture lines. You can palpate an “edge” that is finely demarcated.

What is the most likely diagnosis?

Answer 24

Cephalohematoma

Cephalohematoma is a collection of blood under the periosteum of the outer surface of the skull. It most commonly occurs over the parietal bones and does not cross suture lines because it is below the periosteum. Most slowly resolve over a period of weeks or months and do not require x-ray evaluation.

Question 25

You are presented with this scenario:

• Persistent fetal heart rate > 180 bpm
• Maternal fever

What is the most likely diagnosis?

Answer 25

Chorioamnionitis

Infection of the amniotic fluid is known as chorioamnionitis. It is characterized by maternal fever with or without associated signs and symptoms such as uterine tenderness, foul-smelling amniotic fluid, and maternal/fetal tachycardia. It often follows prolonged (≥ 18 hours) rupture of membranes, which greatly increases the risk of early-onset disease.

Question 26

A post-term newborn presents with:

• History of meconium-stained amniotic fluid
• Current respiratory distress
• Displaced point of maximal cardiac impulse (PMI)

What should you think about as the cause of his respiratory distress?

Answer 26

Pneumothorax

Pneumothorax due to a meconium aspiration is much more common in post-term newborns with a history of meconium-staining of the amniotic fluid. It is a classic exam question. Know it!

Question 27

What virus during pregnancy increases the risk of developing heart failure?

Answer 27

Parvovirus B19 (a.k.a. Fifth Disease)

Parvovirus B19 infection in the pregnant woman between the 10^th and 24^th weeks of gestation can result in a 7–10% fetal risk of severe anemia, heart failure, hydrops fetalis, and death.

Question 28

A white pupillary reflex (leukokoria) in a newborn is associated with which type of tumor?

Answer 28

Retinoblastoma

Leukocoria is also associated with chorioretinitis and advanced retinopathy of prematurity.

Question 29

What should you suspect in an infant who is cyanotic, except when it is crying?

Answer 29

Bilateral Choanal Atresia

Choanal atresia is the most common congenital anomaly of the nose and occurs in ~ 1/7,000 newborns. It is characterized by a bony (90%) or membranous (10%) septum between the nose and the pharynx, unilaterally or bilaterally. Confirm this condition by attempting to pass a small feeding tube through the nares into the hypopharynx. Confirm with CT scan.

Question 30

A term infant with history of C-section delivery presents with tachypnea, grunting, and cyanosis. Lung examination is clear. CXR shows:

• Prominent pulmonary vasculature
• Fluid in the fissures
• Flattening of the diaphragms
• No air bronchograms
• No reticular granularity

What is the most likely diagnosis?

Answer 30

Transient Tachypnea of the Newborn

TTN usually occurs in late preterm infants born via C-section. They present with symptoms similar to respiratory distress syndrome (RDS), but with no air bronchograms or reticular granularity on CXR. TTN is caused by retention of lung fluid at birth, leaving excess fluid that fills the air spaces. The signs and symptoms typically resolve within 12–24 hours or, in severe cases, within 72 hours. Oxygen may be required, but usually no further intervention is necessary.

Question 31

What fetal heart rate defines “fetal bradycardia”?

Answer 31

Fetal Heart Rate < 120 bpm

This is fairly common in post-date fetuses and in those with occiput posterior or transverse presentations.

Question 32

A 5-year-old presents with the following:

• Shortened palpebral fissures
• Epicanthal folds
• Hypoplastic nasal root
• Short, upturned nose
• Hypoplastic philtrum
• Thin upper lip
• Midface hypoplasia
• Weight < 10^th percentile
• Learning problems

What is the most likely diagnosis?

Answer 32

Fetal Alcohol Syndrome

To diagnose fetal alcohol syndrome, you must find abnormalities in each of these 3 areas:

• Facial
• Prenatal or postnatal growth deficiency
• Evidence of cognitive abnormality

Sometimes definitive diagnosis is not made until the child is at least 4–8 years of age because the face is best assessed at this age and developmental evaluation is necessary.

Question 33

You are called by a family about an 8-hour-old infant born at home who now has skin changes that are concerning to the mother. She notes that one side of the baby is pink, while the other side is pale. There is a sharp line of demarcation in the midline between the pink and pale sides.

What is the most likely diagnosis?

Answer 33

Harlequin Color Change

Harlequin color change is a relatively common finding and has no pathologic basis. It is likely due to vasomotor instability and resolves as the infant matures. It generally occurs when affected infants lie on their sides—the lower side is reddened and pink while the upper side is pale/blanching with a sharp line of demarcation in the midline.

Question 34

When should universal screening for vaginal and rectal group B Streptococcus (GBS) be conducted in pregnant women?

Answer 34

Between 35 and 37 Weeks Gestation

Although greatly reduced since the advent of intrapartum antibiotic prophylaxis beginning in 1996, GBSremains a leading cause of neonatal infection. According to the 2011 AAP guidelines for the prevention of perinatal GBS disease in pregnancy, 35–37 weeks of gestation is the optimal timing for prenatal GBS screening.

Question 35

What does cigarette smoking most commonly cause in babies born to mothers who smoke?

Answer 35

Low Birth Weight

Maternal smoking can also lead to a higher incidence of miscarriage, prematurity, and stillbirth. It is also a risk factor for sudden infant death syndrome (SIDS).

Question 36

A 10-day-old premie, born at 28 weeks of gestation, has apnea with bradycardia and desaturation after having been weaned off the ventilator. Head ultrasound and echo are normal. He is tolerating feeds with no spit ups.

What is the best treatment for this infant?

Answer 36

Caffeine

Apnea is a common problem in premature infants, especially those born at < 32 weeks of gestation. The drug of choice for apnea of prematurity is methylxanthine, preferably caffeine. It is used to stimulate respiratory drive.

Question 37

A newborn presents with:

• Anhidrosis
• Ptosis
• Miosis
• Enophthalmos

What is the diagnosis?

Answer 37

Horner Syndrome

Horner syndrome is caused by injury to the sympathetic fibers of the 1st thoracic nerve. Delayed pigmentation of the iris may occur, in addition to the listed findings.

Question 38

Which race has the highest infant mortality rate in the U.S.?

Answer 38

African-Americans

In the U.S., on the sole criterion of race, mortality rates for infants are highest for African Americans (10.9/1,000), followed by Native Americans (8.1), Caucasians (5.1), and finally, Asians and Pacific Islanders (4.2). Neonatal mortality represents 2/3 of the total infant mortality.

Question 39

Estimate the gestational age of this infant:

• Vernix on the back and creases only
• The upper 2/3 of the ear is incurving
• The pinna springs back from folding
• Heel creases are present
• Lanugo present on shoulders only
• Breast tissue is a 3-5 mm nodule
• Labia majora almost covers clitoris

Answer 39

38 Weeks of Gestation

The vernix findings are only in 38–39 weeks of gestation; the upper 2/3 incurving at 36–38 weeks; pinna springing back at 36–39 weeks; heel creases at 38–41 weeks; lanugo on shoulders at 38–41 weeks; breast tissue at 3- to 5-mm nodule is 38 weeks; and the labia findings at 36–39 weeks. Best overlap of all of these is 38 weeks of gestation.

Question 40

Where is surfactant synthesized and stored in the fetus?

Answer 40

Type II Alveolar Cells

Surfactant is made up of dipalmitoylphosphatidylcholine (lecithin), phosphatidylglycerol, apoproteins (surfactant proteins SP-A, -B,-C, -D), and cholesterol. Mature levels of pulmonary surfactant are usually present at ≥ 35 of weeks gestation.

Question 41

Diethylstilbestrol (DES) is associated with increasing the risk of what cancer in girls born to mothers on this agent?

Answer 41

Vaginal Adenocarcinoma

Girls born to women who used DES prior to 12 weeks of gestation have an increased risk of vaginal adenocarcinoma at a later age. There also are reports of uterine abnormalities, vaginal adenosis, and male infertility.

Question 42

A breastfed infant presents at 19 hours of life with new onset jaundice. Does this require immediate evaluation or is observation sufficient?

Answer 42

Immediate Evaluation

Jaundice that appears in the first 24 hours of life is always concerning and could indicate many pathologic conditions, including sepsis or hemolytic anemia. It is not due to breastfeeding.

Question 43

What is the definition of low birth weight (LBW)?

Answer 43

Birth Weight < 2,500 grams

An infant with a birth weight < 2,500 grams, regardless of gestational age, is considered LBW.

Question 44

An infant was born at 28 weeks of gestation. He was given surfactant at birth and intubated for acute respiratory distress. He was transitioned to nasal CPAP but had to be reintubated twice due to pneumonia and sepsis. He is now term but persistently requires oxygen. He is fluid restricted and on a concentrated formula diet.

What is the reason for his persistent oxygen requirement?

Answer 44

Bronchopulmonary Dysplasia (BPD)

BPD, a.k.a. neonatal chronic lung disease, occurs most commonly in preterm infants born at < 30 weeks of gestation. It is characterized by persistent respiratory insufficiency, despite the absence and elimination of all other correctable causes. Infection and fluid overload are known risk factors for developing BPD.

Question 45

Which specific race and associated birth weight group has the highest mortality rate in the U.S.?

Answer 45

Caucasians with Birth Weight < 500 Grams

Question 46

ACE inhibitors increase the risk of what congenital abnormalities?

Answer 46

Renal Dysgenesis, Oligohydramnios, and Skull Ossification Defects

ACE inhibitor use during the 2^nd and 3^rd trimesters increases the risk of these abnormalities.

Question 47

A newborn presents after a difficult breech delivery with:

• Paralysis of the right arm and hand
• Right hand is held in a claw-like posturing.

What is the diagnosis?

Answer 47

Klumpke Paralysis

Klumpke palsy most commonly occurs during breech deliveries and is caused by damage to the lower part of the brachial plexus. Generally, this involves the 7th and 8th cervical roots and the 1st thoracic component of the brachial plexus. Klumpke’s is less likely to improve spontaneously than Erb palsy but still may respond to physical therapy.

Question 48

What is the leading cause of infant death in the United States?

Answer 48

Congenital Malformations

Congenital malformations account for ~ 25% of infant mortality in the U.S.

Question 49

A late trimester pregnant patient presents with:

• Evidence of hemolysis
• Elevated AST and ALT
• Thrombocytopenia

What is the likely diagnosis?

Answer 49

HELLP Syndrome

HELLP syndrome is characterized by hemolysis, elevated liver enzymes, and a low platelet count. The pathogenesis of this obstetric complication is unclear, but it may be a variant of preeclampsia. Early diagnosis is critical because morbidity and mortality rates are as high as 25%.

Question 50

Fill in the blank using either the words “decreases” or “increases”:

• Mean pulmonary pressure _______ dramatically at birth.
• Pulmonary blood flow ________ dramatically at birth.
• Pulmonary vascular resistance _______ dramatically at birth.

Answer 50

Decreases, Increases, Decreases

These are the changes in pressures and flow of the pulmonary vascular system as the baby transitions from in utero to breathing air.

Question 51

What is evaluated by measuring from the top of the uterine fundus to the symphysis pubis?

Answer 51

Fundal Height

Fundal height measurements are still very important and continue to be the simplest screening method to detect intrauterine growth restriction (IUGR).

Question 52

An infant is born to a mother with a positive RPR. The newborn has the following:

• Jaundice
• Hepatosplenomegaly
• Rhinitis (severe)
• Vesicular skin rash
• Chorioretinitis

What is the best treatment?

Answer 52

Aqueous Crystalline Penicillin G

These are clinical findings of congenital syphilis. All infants born to seropositive (RPR or VDRL) mothers require careful examination and the same nontreponemal syphilis test that was performed on the mother. Treat infants who are proven or highly likely to have congenital syphilis with aqueous crystalline penicillin G 50,000 units/kg/dose IV every 12 hours for the first 7 days of life, then every 8 hours thereafter to complete 10 days. An alternative is procaine-penicillin 50,000 units/kg/dose IM 1×/day for 10 days.

Question 53

What congenital malformation can carbamazepine and valproic acid cause?

Answer 53

Spina Bifida

Use of carbamazepine carries a < 1% risk of spina bifida when exposure occurs between 15 and 29 days after conception, and valproic acid carries a 2% risk of spina bifida when used in the first 30 days after conception. Antiseizure medications are folate antagonists, so it is imperative that mothers taking antiepileptics also take folic acid.

Question 54

What is the definition of small for gestational age (SGA)?

Answer 54

Birth Weight < 10^th Percentile for Gestational Age

This definition includes many healthy infants! Not all SGA fetuses are pathologically growth restricted; some are just constitutionally small. Intrauterine growth restriction (IUGR) refers to a condition in which a fetus is not able to achieve its genetically determined potential size. By definition, this term excludes those fetuses that are SGA but are not pathologically small.

Question 55

What type of placenta will most identical twins (only 1 ovum before division) have?

Answer 55

Diamniotic, Monochorionic Twin Placentas

Monochorionic membranes are thin and translucent. At delivery, these membranes can be separated easily to reveal a single chorionic surface that covers the villous tissue. This formation is referred to as diamniotic, monochorionic twin placentas. Rarely, if the twins separated before the formation of the chorionic cavity (before day 3), they could form separate diamniotic, dichorionic placentas (commonly associated with fraternal twins).

Question 56

A newborn presents with the following:

• Jitteriness
• Irritability
• Tremulousness
• Muscle rigidity
• Intracranial hemorrhages

What illicit drug used by the mother during pregnancy is most likely responsible for these findings?

Answer 56

Cocaine

Chronic cocaine use by the mother during pregnancy results in jitteriness, irritability, tremulousness, and muscle rigidity in the infant. If these effects occur without the intracranial hemorrhages, they commonly resolve several days after birth without known long-term effects. Increased risk of placental abruption and intracranial hemorrhage are associated with cocaine use near delivery.

Question 57

If an infant presents with meconium ileus, what diagnosis should you always consider?

Answer 57

Cystic Fibrosis

Meconium ileus is a lower small bowel obstruction that results from impaction due to meconium; up to 50% are complicated by volvulus, intestinal atresia, or perforation. It is usually due to CF. Look for CF by genetic testing of all infants with meconium ileus.

Question 58

A 1-month-old boy who was born at 31-weeks-gestation with no history of hyaline membrane disease presents with progressive:

• Tachypnea
• Dyspnea with feeding
• Occasional cyanosis
• Cough with wheezing
• CXR shows bilateral reticular infiltrates with development of multi-cystic lesions.

What is the most likely diagnosis?

Answer 58

Interstitial Pulmonary Fibrosis

(Wilson-Mikity Syndrome)

It is seen in infants without a history of hyaline membrane disease who are

Question 59

At the newborn examination, you note a collection of edema fluid and blood in the soft tissue of the skull. The edema crosses suture lines and the midline of the skull.

What is the most likely diagnosis?

Answer 59

Caput Succedaneum

Caput succedaneum is due to the forces of labor as the presenting part is pushed through the birthing process. The incidence is increased with prolonged labor and vacuum extraction. The caput is above the periosteum, which allows the edema to cross suture lines and the midline. Skull x-rays are not indicated and the caput will resolve over several days.

Question 60

A 1-day-old infant is noted to have the following:

• Bounding peripheral pulses
• Prominent apical impulse
• Systolic thrill at the 2^nd intercostal space
• Continuous machinery-like murmur, which begins soon after S1, reaches maximal intensity at the end of systole, and wanes in late systole.

What is the most likely diagnosis?

Answer 60

Patent Ductus Arteriosus

In an infant with continued hypoxia after birth, the ductus arteriosus can remain patent. Clinically, a PDA presents with the findings listed in the scenario. Be sure to know these signs! Interestingly, there is increased incidence of PDA in infants born > 3,000 feet elevation.