Vitamin K supplementation is given to neonates to prevent _____ .
Q2
A mother delivers in a rural area under the guidance of a skilled care attendant. Which of the following statements is incorrect regarding the care provided by the skilled care attendant at birth?
Q3
A baby presents with hydrocephalus, intracranial calcifications, and chorioretinitis. What is the most probable diagnosis?
Q4
A neonate presents with failure to pass meconium. The structure absent in the pathology lies in which of the following layers?
Q5
A 5-day-old, 2200 g (4 lb 14 oz) male newborn is brought to the physician because of poor feeding and irritability. He was born at 36 weeks' gestation after the pregnancy was complicated by premature rupture of membranes. His APGAR scores at delivery were 5 and 8 at 1 and 5 minutes, respectively. He appears lethargic. His temperature is 38.5°C (101.3°F), pulse is 170/min, and respirations are 63/min. Examination shows scleral icterus. Subcostal retractions and nasal flaring are present. Capillary refill time is 4 seconds. Laboratory studies are ordered and an x-ray of the chest is scheduled. Which of the following is the most appropriate next step in management?
Q6
A 9-hour-old newborn female is found in the newborn nursery with a diffuse swelling of the scalp not present at birth. The child was born at 38 weeks of gestation to a 28-year-old gravida 3. The mother went into spontaneous labor, but the delivery was complicated by a prolonged second stage of labor. A vacuum-assisted vaginal delivery was eventually performed. The child’s Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. The pregnancy was complicated by preeclampsia in the mother which was well-controlled throughout the pregnancy. On physical exam, the child appears to be in mild distress and has a 4x5 cm ecchymotic area of swelling over the bilateral parietal bones. Serial assessments of the child’s head circumference over the next 12 hours show no change in the size of the swelling.
This patient’s condition affects which of the following spaces or potential spaces?
Q7
A 2-week-old neonate in the intensive care unit presents as severely ill. His mother says he was a bit irritated earlier this week, and his condition deteriorated quickly. It is apparent that he is in constant pain. He could not be fed easily and vomited three times since yesterday alone. The physical examination is remarkable for a distended abdomen and diminished bowel sounds. The neonate is sent for an abdominal/chest X-ray, which shows pneumatosis intestinalis and pneumoperitoneum. The neonate was born at 32 weeks of gestation by a normal vaginal delivery. Which of the following is the best next step for this patient?
Q8
A 4670-g (10-lb 5-oz) male newborn is delivered at term to a 26-year-old woman after prolonged labor. Apgar scores are 9 and 9 at 1 and 5 minutes. Examination in the delivery room shows swelling, tenderness, and crepitus over the left clavicle. There is decreased movement of the left upper extremity. Movement of the hands and wrists are normal. A grasping reflex is normal in both hands. An asymmetric Moro reflex is present. The remainder of the examination shows no abnormalities and an anteroposterior x-ray confirms the diagnosis. Which of the following is the most appropriate next step in management?
Q9
A 1-month-old girl is brought to the physician for evaluation of a rash on her face that first appeared 3 days ago. She was delivered at term after an uncomplicated pregnancy. She is at the 25th percentile for length and 40th percentile for weight. Examination shows small perioral vesicles surrounded by erythema and honey-colored crusts. Laboratory studies show:
At birth Day 30
Hemoglobin 18.0 g/dL 15.1 g/dL
Leukocyte count 7,600/mm³ 6,830/mm³
Segmented neutrophils 2% 3%
Eosinophils 13% 10%
Lymphocytes 60% 63%
Monocytes 25% 24%
Platelet count 220,000/mm³ 223,000/mm³
Which of the following underlying conditions is most likely responsible for this patient's predisposition to skin infections?
Q10
A newborn is evaluated by the on-call pediatrician. She was born at 33 weeks gestation via spontaneous vaginal delivery to a 34-year-old G1P1. The pregnancy was complicated by poorly controlled diabetes mellitus type 2. Her birth weight was 3,700 g and the appearance, pulse, grimace, activity, and respiration (APGAR) scores were 7 and 8 at 1 and 5 minutes, respectively. The umbilical cord had 3 vessels and the placenta was tan-red with all cotyledons intact. Fetal membranes were tan-white and semi-translucent. The normal-appearing placenta and cord were sent to pathology for further evaluation. On physical exam, the newborn’s vital signs include: temperature 36.8°C (98.2°F), blood pressure 60/44 mm Hg, pulse 185/min, and respiratory rate 74/min. She presents with nasal flaring, subcostal retractions, and mild cyanosis. Breath sounds are decreased at the bases of both lungs. Arterial blood gas results include a pH of 6.91, partial pressure of carbon dioxide (PaCO2) 97 mm Hg, partial pressure of oxygen (PaO2) 25 mm Hg, and base excess of 15.5 mmol/L (reference range: ± 3 mmol/L). What is the most likely diagnosis?
Neonatal infections US Medical PG Practice Questions and MCQs
Question 1: Vitamin K supplementation is given to neonates to prevent _____ .
A. Hemorrhagic disease of the newborn (Correct Answer)
B. Scurvy
C. Keratomalacia
D. Breast milk jaundice
E. Rickets
Explanation: ***Hemorrhagic disease of the newborn***
- Neonates have low levels of **vitamin K-dependent clotting factors** (II, VII, IX, X) due to poor placental transfer, sterile gut, and low vitamin K in breast milk.
- Vitamin K supplementation at birth prevents potentially life-threatening bleeding episodes, known as **hemorrhagic disease of the newborn (VKDB)**, by ensuring adequate clotting factor production.
*Scurvy*
- Scurvy is caused by **vitamin C deficiency**, leading to impaired collagen synthesis.
- Symptoms include **gingival bleeding**, skin hemorrhages, and poor wound healing, which are distinct from vitamin K deficiency.
*Keratomalacia*
- Keratomalacia is a severe eye condition resulting from **vitamin A deficiency**, characterized by drying and clouding of the cornea.
- It leads to **blindness** and is not related to vitamin K metabolism.
*Breast milk jaundice*
- Breast milk jaundice is a common and usually benign condition in neonates where **breast milk components** interfere with bilirubin metabolism, prolonging physiological jaundice.
- It is not prevented by vitamin K and is entirely distinct from coagulation disorders.
*Rickets*
- Rickets is caused by **vitamin D deficiency**, resulting in defective bone mineralization and skeletal deformities.
- Clinical features include **bowed legs**, rachitic rosary, and delayed fontanelle closure, which are unrelated to coagulation or vitamin K.
Question 2: A mother delivers in a rural area under the guidance of a skilled care attendant. Which of the following statements is incorrect regarding the care provided by the skilled care attendant at birth?
A. Start breastfeeding as early as possible
B. Cover the baby's head and body
C. Bathe the baby with warm water (Correct Answer)
D. Clear the eyes with a sterile swab
E. Dry the baby thoroughly and stimulate breathing
Explanation: ***Bathe the baby with warm water***
- **Delaying the first bath** for at least 6-24 hours after birth is recommended to prevent **hypothermia** and promote **skin-to-skin contact** for bonding and breastfeeding.
- Early bathing can remove **vernix caseosa**, which provides natural antimicrobial protection and moisturization to the newborn's skin.
*Start breastfeeding as early as possible*
- **Early initiation of breastfeeding**, ideally within the first hour of birth, is crucial for both mother and baby.
- It promotes **uterine contractions** to prevent **postpartum hemorrhage** and provides the newborn with **colostrum**, rich in antibodies.
*Cover the baby's head and body*
- Covering the newborn's head and body is essential to prevent **heat loss** and maintain a stable **body temperature**, immediately after birth.
- Newborns are highly susceptible to **hypothermia** due to their large surface area to mass ratio and immature thermoregulation.
*Clear the eyes with a sterile swab*
- Clearing the newborn's eyes with a sterile swab is a standard part of immediate newborn care to remove any **mucus or blood** that might have entered during delivery.
- This helps prevent **ophthalmia neonatorum**, especially if the mother has an infection like gonorrhea or chlamydia.
*Dry the baby thoroughly and stimulate breathing*
- **Drying the baby immediately** after birth is a critical first step in newborn resuscitation and care.
- It helps prevent **hypothermia** and provides **tactile stimulation** to initiate breathing and crying, which is essential for transitioning from fetal to neonatal circulation.
Question 3: A baby presents with hydrocephalus, intracranial calcifications, and chorioretinitis. What is the most probable diagnosis?
A. Toxoplasmosis (Correct Answer)
B. Syphilis
C. Cytomegalovirus (CMV) infection
D. Rubella
E. Herpes Simplex Virus (HSV) infection
Explanation: **Toxoplasmosis**
- The classic triad of **hydrocephalus**, **intracranial calcifications**, and **chorioretinitis** is highly characteristic of congenital toxoplasmosis.
- These findings result from the parasite's invasive nature and predilection for the central nervous system and eyes of the developing fetus.
- Calcifications in toxoplasmosis are typically **diffuse and scattered** throughout the brain parenchyma.
*Syphilis*
- Congenital syphilis typically presents with **rhinitis**, **skin rash**, **hepatosplenomegaly**, and **bone abnormalities** (e.g., periostitis, saber shins).
- While neurological complications can occur, the specific triad of hydrocephalus, intracranial calcifications, and chorioretinitis is not characteristic.
*Cytomegalovirus (CMV) infection*
- Congenital CMV can cause **periventricular calcifications** (not diffuse calcifications), **microcephaly**, and **sensorineural hearing loss**.
- While chorioretinitis can occur, hydrocephalus is less frequent, and the calcification pattern differs from toxoplasmosis (CMV shows periventricular pattern vs. diffuse in toxoplasmosis).
*Rubella*
- Congenital rubella syndrome is known for causing the classic triad of **cataracts**, **sensorineural hearing loss**, and **congenital heart defects** (e.g., patent ductus arteriosus, pulmonary artery stenosis).
- Intracranial calcifications and hydrocephalus are not typical presentations of congenital rubella.
*Herpes Simplex Virus (HSV) infection*
- Neonatal HSV typically presents with **vesicular skin lesions**, **encephalitis**, and **disseminated disease** affecting liver and lungs.
- While HSV can cause encephalitis with brain involvement, the classic triad of hydrocephalus, diffuse intracranial calcifications, and chorioretinitis is not characteristic of HSV infection.
Question 4: A neonate presents with failure to pass meconium. The structure absent in the pathology lies in which of the following layers?
A. A, B
B. B, C
C. C, D (Correct Answer)
D. A, D
E. B, D
Explanation: ***C, D***
- The neonate's symptom of **failure to pass meconium** is characteristic of **Hirschsprung disease**, which is caused by the absence of **ganglion cells** in the distal colon.
- The missing ganglion cells are typically found in the **submucosal (Meissner) plexus** and the **myenteric (Auerbach) plexus**, corresponding to layers C and D in the provided image.
*A, B*
- Layer A represents the **mucosa** (specifically the glandular epithelium), and layer B represents the **lamina propria** or potentially the muscularis mucosa.
- These layers do not primarily house the ganglion cells implicated in Hirschsprung disease.
*B, C*
- Layer B is the **lamina propria** or **muscularis mucosa**, and layer C is the **submucosa**.
- While the submucosa (C) contains the Meissner plexus, layer B does not contain ganglion cells relevant to this pathology.
*B, D*
- Layer B is the **lamina propria/muscularis mucosa**, and layer D is the **muscularis propria**.
- While the myenteric plexus (associated with D) is affected in Hirschsprung disease, layer B does not contain ganglion cells, and this option incorrectly excludes the submucosal plexus (layer C), which also contains ganglion cells that are absent in this condition.
*A, D*
- Layer A is the **mucosa**, and layer D is the **muscularis propria** (outer muscle layer).
- The mucosa (A) does not contain the ganglion cells, while the myenteric plexus (associated with D) is affected, but this option incorrectly includes A and omits the submucosal plexus (C).
Question 5: A 5-day-old, 2200 g (4 lb 14 oz) male newborn is brought to the physician because of poor feeding and irritability. He was born at 36 weeks' gestation after the pregnancy was complicated by premature rupture of membranes. His APGAR scores at delivery were 5 and 8 at 1 and 5 minutes, respectively. He appears lethargic. His temperature is 38.5°C (101.3°F), pulse is 170/min, and respirations are 63/min. Examination shows scleral icterus. Subcostal retractions and nasal flaring are present. Capillary refill time is 4 seconds. Laboratory studies are ordered and an x-ray of the chest is scheduled. Which of the following is the most appropriate next step in management?
A. Methimazole therapy
B. Phototherapy
C. Endotracheal intubation
D. Ampicillin and gentamicin therapy (Correct Answer)
E. Surfactant therapy
Explanation: ***Ampicillin and gentamicin therapy***
- The newborn presents with **fever**, **tachycardia**, **tachypnea**, **lethargy**, and **poor feeding**, which are classic signs of **neonatal sepsis**. Prompt initiation of **broad-spectrum antibiotics** (like ampicillin and gentamicin) is crucial while awaiting culture results.
- The history of **premature rupture of membranes** is a significant risk factor for **neonatal infection**.
*Methimazole therapy*
- **Methimazole** is used to treat **hyperthyroidism**. While the infant has tachycardia, there is no other evidence of thyroid dysfunction, and hyperthyroidism is not the primary concern given the acute septic picture.
- The presented symptoms are more consistent with an acute infectious process rather than a hormonal imbalance.
*Phototherapy*
- **Phototherapy** is used to treat **neonatal hyperbilirubinemia** (jaundice), which is indicated by **scleral icterus**. However, severe sepsis needs to be addressed first due to its life-threatening nature.
- While conjugated hyperbilirubinemia can be a sign of sepsis, treating the underlying infection takes precedence over phototherapy at this stage.
*Endotracheal intubation*
- Although the infant shows **respiratory distress** (tachypnea, subcostal retractions, nasal flaring), intubation is generally reserved for severe respiratory failure, apnea, or inability to maintain adequate oxygenation despite other respiratory support.
- Addressing the underlying cause (sepsis) and providing **antibiotics** are the immediate priorities before considering invasive airway management unless respiratory failure is imminent.
*Surfactant therapy*
- **Surfactant therapy** is primarily used to treat **respiratory distress syndrome (RDS)** in premature infants due to surfactant deficiency. While this infant is premature, the current presentation of fever, lethargy, and poor feeding points strongly to sepsis, not isolated RDS.
- The respiratory distress here is more likely a manifestation of sepsis rather than primary surfactant deficiency at 5 days of age.
Question 6: A 9-hour-old newborn female is found in the newborn nursery with a diffuse swelling of the scalp not present at birth. The child was born at 38 weeks of gestation to a 28-year-old gravida 3. The mother went into spontaneous labor, but the delivery was complicated by a prolonged second stage of labor. A vacuum-assisted vaginal delivery was eventually performed. The child’s Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. The pregnancy was complicated by preeclampsia in the mother which was well-controlled throughout the pregnancy. On physical exam, the child appears to be in mild distress and has a 4x5 cm ecchymotic area of swelling over the bilateral parietal bones. Serial assessments of the child’s head circumference over the next 12 hours show no change in the size of the swelling.
This patient’s condition affects which of the following spaces or potential spaces?
A. Into the lateral ventricles
B. Between dura and arachnoid mater
C. Between periosteum and galea aponeurosis
D. Between scalp and galea aponeurosis
E. Between periosteum and skull (Correct Answer)
Explanation: ***Between periosteum and skull***
- The symptoms described, including **diffuse swelling of the scalp not present at birth** and **ecchymotic area of swelling over the bilateral parietal bones** that **does not cross suture lines** (implied by location and typical presentation), are classic for a **cephalohematoma**.
- A cephalohematoma involves bleeding **between the periosteum and the skull bone**, which explains why it is limited by the suture lines (as the periosteum firmly attaches at the sutures).
*Between periosteum and galea aponeurosis*
- This description does not correspond to a standard anatomical space in the scalp layers.
- The **subgaleal space** (where subgaleal hemorrhage occurs) is actually located **between the galea aponeurotica and the periosteum**, not between periosteum and galea.
- A subgaleal hemorrhage is characterized by swelling that **diffusely crosses suture lines** and can be very extensive, leading to significant blood loss and systemic symptoms, which is not indicated here by the stable head circumference and mild distress.
*Between dura and arachnoid mater*
- This potential space is where a **subdural hematoma** occurs, which involves bleeding between the dura mater and the arachnoid mater, typically within the cranial vault.
- Subdural hematomas are intracranial hemorrhages and would present with neurological symptoms like seizures, lethargy, or altered consciousness, which are not described in this case of an external scalp swelling.
*Into the lateral ventricles*
- Bleeding into the lateral ventricles is known as an **intraventricular hemorrhage (IVH)**, which is an intracranial bleed primarily seen in premature infants.
- IVH would manifest with severe neurological symptoms, such as apnea, bradycardia, or focal neurological deficits, and would not cause the external scalp swelling described.
*Between scalp and galea aponeurosis*
- This refers to the most superficial layer of the scalp, and swelling in this area would typically be a superficial soft tissue injury like a **caput succedaneum**.
- A caput succedaneum is present at birth, poorly demarcated, and crosses suture lines, which contradicts the described swelling not present at birth and limited by the parietal bones.
Question 7: A 2-week-old neonate in the intensive care unit presents as severely ill. His mother says he was a bit irritated earlier this week, and his condition deteriorated quickly. It is apparent that he is in constant pain. He could not be fed easily and vomited three times since yesterday alone. The physical examination is remarkable for a distended abdomen and diminished bowel sounds. The neonate is sent for an abdominal/chest X-ray, which shows pneumatosis intestinalis and pneumoperitoneum. The neonate was born at 32 weeks of gestation by a normal vaginal delivery. Which of the following is the best next step for this patient?
A. Hyperbaric oxygen
B. Surfactants
C. Exchange transfusion
D. Surgery (Correct Answer)
E. Epinephrine
Explanation: ***Surgery***
- The presentation of a premature neonate with **abdominal distension**, diminished bowel sounds, vomiting, and **pneumatosis intestinalis** (gas within the bowel wall) with **pneumoperitoneum** (free air) on X-ray is diagnostic of **necrotizing enterocolitis (NEC) with intestinal perforation**.
- Pneumoperitoneum indicates bowel perforation and is an **absolute indication for emergency surgical intervention** to resect necrotic bowel and prevent life-threatening sepsis and peritonitis.
- This represents **Bell's stage III NEC** requiring urgent laparotomy.
*Hyperbaric oxygen*
- **Hyperbaric oxygen therapy** is used in conditions like severe infections, decompression sickness, or chronic wounds, but it is not indicated for acute abdominal emergencies like NEC.
- It does not address the underlying intestinal necrosis or perforation in NEC.
*Surfactants*
- **Surfactants** are primarily used to treat or prevent **respiratory distress syndrome** in premature infants by improving lung function.
- They have no role in the management of necrotizing enterocolitis, which is an intestinal pathology.
*Exchange transfusion*
- **Exchange transfusion** is primarily indicated for severe hyperbilirubinemia or hemolytic disease of the newborn to remove bilirubin and antibodies.
- It is not a treatment for necrotizing enterocolitis and would not address the intestinal damage.
*Epinephrine*
- **Epinephrine** is a potent vasoconstrictor and bronchodilator used in emergencies like **anaphylaxis** or cardiac arrest.
- It is not a primary treatment for necrotizing enterocolitis and could potentially worsen intestinal ischemia due to its vasoconstrictive effects.
Question 8: A 4670-g (10-lb 5-oz) male newborn is delivered at term to a 26-year-old woman after prolonged labor. Apgar scores are 9 and 9 at 1 and 5 minutes. Examination in the delivery room shows swelling, tenderness, and crepitus over the left clavicle. There is decreased movement of the left upper extremity. Movement of the hands and wrists are normal. A grasping reflex is normal in both hands. An asymmetric Moro reflex is present. The remainder of the examination shows no abnormalities and an anteroposterior x-ray confirms the diagnosis. Which of the following is the most appropriate next step in management?
A. Nerve conduction study
B. Splinting of the arm
C. MRI of the clavicle
D. Physical therapy
E. Pin sleeve to the shirt (Correct Answer)
Explanation: ***Pin sleeve to the shirt***
- This is the appropriate management for a **clavicular fracture** in a newborn, as it provides **gentle immobilization** for comfort and healing.
- The goal is to limit arm movement minimally without rigid fixation, allowing the fracture to **heal spontaneously** over 7–10 days.
*Nerve conduction study*
- This study is used to assess **nerve function** and is typically performed if there's suspicion of a **brachial plexus injury**, which is not the primary concern given the clear signs of a clavicular fracture.
- While an asymmetric Moro reflex can indicate nerve injury, the presence of **swelling, tenderness, crepitus, and decreased movement** of the upper extremity, especially confirmed by X-ray, points directly to a fracture rather than primarily nerve damage.
*Splinting of the arm*
- **Splinting** is generally too rigid and unnecessary for a neonatal clavicular fracture, which typically heals well with simple immobilization of the arm to the chest wall.
- Over-immobilization can restrict normal movement and potentially delay development.
*MRI of the clavicle*
- An **anteroposterior X-ray** has already confirmed the diagnosis of a clavicular fracture, making an MRI an **unnecessary and expensive** additional imaging test in this context.
- MRI is typically reserved for more complex bone or soft tissue injuries, or when plain radiographs are inconclusive.
*Physical therapy*
- **Physical therapy** is not indicated at the initial stage of managing a clavicular fracture as the priority is **immobilization** for healing.
- It might be considered later if there are persistent issues with range of motion or muscle weakness after fracture healing.
Question 9: A 1-month-old girl is brought to the physician for evaluation of a rash on her face that first appeared 3 days ago. She was delivered at term after an uncomplicated pregnancy. She is at the 25th percentile for length and 40th percentile for weight. Examination shows small perioral vesicles surrounded by erythema and honey-colored crusts. Laboratory studies show:
At birth Day 30
Hemoglobin 18.0 g/dL 15.1 g/dL
Leukocyte count 7,600/mm³ 6,830/mm³
Segmented neutrophils 2% 3%
Eosinophils 13% 10%
Lymphocytes 60% 63%
Monocytes 25% 24%
Platelet count 220,000/mm³ 223,000/mm³
Which of the following underlying conditions is most likely responsible for this patient's predisposition to skin infections?
A. Diamond-Blackfan syndrome
B. Acute lymphoblastic leukemia
C. Selective IgA deficiency
D. Parvovirus B19 infection
E. Severe congenital neutropenia (Correct Answer)
Explanation: ***Severe congenital neutropenia***
- The patient's **segmented neutrophil count** is extremely low (2-3%), indicating **neutropenia**, which predisposes to bacterial skin infections like the described **impetigo** (perioral vesicles, erythema, honey-colored crusts).
- This condition is characterized by a **maturation arrest of myeloid cells** in the bone marrow, leading to a profound deficiency of neutrophils from birth.
*Diamond-Blackfan syndrome*
- This is a rare congenital **pure red cell aplasia**, meaning it primarily affects **red blood cell production**, leading to anemia.
- It does not directly cause **neutropenia** or increased susceptibility to bacterial skin infections.
*Acute lymphoblastic leukemia*
- While it can cause **bone marrow suppression** and neutropenia, it is very rare in infants and typically presents with a range of symptoms, including fever, pallor, petechiae, and sometimes abnormal lymphocyte counts, which are not seen here.
- The presented leukocyte counts and differential do not suggest leukemia.
*Selective IgA deficiency*
- This condition leads to an increased risk of **mucosal infections** in the respiratory, gastrointestinal, and genitourinary tracts, but it does not directly cause **bacterial skin infections** like impetigo or lead to neutropenia.
- The primary defect is in **humoral immunity**, not cellular immunity or phagocyte function.
*Parvovirus B19 infection*
- Parvovirus B19 primarily targets **erythroid progenitor cells**, causing **transient aplastic crisis** and anemia, especially in individuals with underlying hemolytic disorders.
- It does not cause **neutropenia** or predispose to bacterial skin infections in the manner described.
Question 10: A newborn is evaluated by the on-call pediatrician. She was born at 33 weeks gestation via spontaneous vaginal delivery to a 34-year-old G1P1. The pregnancy was complicated by poorly controlled diabetes mellitus type 2. Her birth weight was 3,700 g and the appearance, pulse, grimace, activity, and respiration (APGAR) scores were 7 and 8 at 1 and 5 minutes, respectively. The umbilical cord had 3 vessels and the placenta was tan-red with all cotyledons intact. Fetal membranes were tan-white and semi-translucent. The normal-appearing placenta and cord were sent to pathology for further evaluation. On physical exam, the newborn’s vital signs include: temperature 36.8°C (98.2°F), blood pressure 60/44 mm Hg, pulse 185/min, and respiratory rate 74/min. She presents with nasal flaring, subcostal retractions, and mild cyanosis. Breath sounds are decreased at the bases of both lungs. Arterial blood gas results include a pH of 6.91, partial pressure of carbon dioxide (PaCO2) 97 mm Hg, partial pressure of oxygen (PaO2) 25 mm Hg, and base excess of 15.5 mmol/L (reference range: ± 3 mmol/L). What is the most likely diagnosis?
A. Fetal alcohol syndrome
B. Congenital pneumonia
C. Infant respiratory distress syndrome (Correct Answer)
D. Transient tachypnea of the newborn
E. Meconium aspiration syndrome
Explanation: ***Infant respiratory distress syndrome***
- This premature infant (33 weeks gestation) presents with severe respiratory distress, including nasal flaring, retractions, cyanosis, and decreased breath sounds, along with **hypoxia and hypercapnia** on ABG, which is characteristic of **infant respiratory distress syndrome (IRDS)** due to **surfactant deficiency**.
- The mother's poorly controlled **diabetes mellitus type 2** is a known risk factor, as maternal hyperglycemia can inhibit fetal lung maturation and surfactant production.
*Fetal alcohol syndrome*
- This syndrome is characterized by distinct **facial anomalies**, growth restriction, and central nervous system abnormalities, none of which are detailed in the presentation.
- Respiratory distress as the primary and severe presenting symptom is not typical of fetal alcohol syndrome.
*Congenital pneumonia*
- While possible in a newborn, congenital pneumonia usually presents with signs of sepsis, such as **fever or hypothermia**, lethargy, and poor feeding, in addition to respiratory symptoms.
- The ABG results and the strong risk factor of prematurity with maternal diabetes point more specifically towards IRDS.
*Transient tachypnea of the newborn*
- This condition typically presents with **mild to moderate respiratory distress** and usually resolves within 24-48 hours, often seen in term or late pre-term infants due to delayed clearance of fetal lung fluid.
- The severe respiratory distress, marked hypoxemia, hypercapnia, and prematurity in this case are inconsistent with TTN.
*Meconium aspiration syndrome*
- This occurs when the newborn inhales **meconium-stained amniotic fluid**, leading to respiratory distress, and is seen more commonly in **post-term or term infants** experiencing fetal distress.
- The infant was born at 33 weeks, which is preterm, and there is no mention of meconium-stained amniotic fluid, making this diagnosis less likely.
