DISEASES OF INFANCY Generated questions

1. What is a congenital anomaly?

An anatomic defect recognized at birth; not all genetic diseases are congenital and not all congenital diseases are genetic.

2. Major causes of congenital anomalies?

Genetic, maternal conditions (DM, SLE, hypothyroidism), drugs/chemicals, congenital infections (TORCH), ionizing radiation, multifactorial causes.

3. How does maternal diabetes cause fetal macrosomia?

Fetal hyperinsulinemia increases muscle mass and fat deposition.

4. Which maternal antibody in SLE causes congenital heart block?

Anti-Ro antibodies.

5. What lab finding suggests congenital infection?

Increased cord blood IgM.

6. What is the rubella embryopathy tetrad?

Cataracts, cardiac defects, deafness, mental retardation.

7. Most common congenital viral infection?

CMV.

8. Causes of oligohydramnios?

Chronic leakage of amniotic fluid, uteroplacental insufficiency, fetal renal agenesis.

9. Features of Potter sequence?

Flattened facies, skull compression, dysplastic ears, underdeveloped chest, clubfeet.

10. Difference between malformation, deformation, disruption?

Malformation: intrinsic defect; Deformation: extrinsic mechanical force; Disruption: destruction of previously normal tissue.

11. Most common cause of spontaneous abortion?

Fetal chromosomal abnormalities (especially trisomy 16).

12. Definition of SIDS?

Sudden unexplained death of infant <1 year after complete evaluation.

13. Most common autopsy finding in SIDS?

Petechiae on pleura, epicardium, thymus.

14. Define prematurity.

Birth before 37 weeks gestation.

15. Most common cause of prematurity?

PPROM (preterm premature rupture of membranes).

16. Fundamental defect in RDS?

Decreased surfactant from immature type II pneumocytes.

17. Factors that decrease surfactant?

Insulin, absence of cortisol surge (C-section without labor).

18. CXR finding in RDS?

Ground-glass appearance.

19. Two O₂-therapy complications in RDS?

Retinopathy of prematurity, bronchopulmonary dysplasia.

20. Pneumatosis intestinalis indicates what disease?

Necrotizing enterocolitis (NEC).

21. Symmetric vs asymmetric FGR?

Symmetric: intrinsic fetal cause; Asymmetric: uteroplacental insufficiency with brain sparing.

22. What antibody causes HDN?

Maternal IgG.

23. Why is first pregnancy spared in Rh HDN?

Mother becomes sensitized only after first exposure.

24. Most severe form of Rh HDN?

Hydrops fetalis.

25. Dangerous bilirubin complication in Rh HDN?

Kernicterus.

26. Spherocytes: present in ABO or Rh HDN?

Present in ABO HDN; absent in Rh HDN.

27. Prevention of Rh HDN?

Anti-D immunoglobulin (RhoGAM) at 28 weeks + within 72 hours postpartum.

28. Defect in PKU?

Phenylalanine hydroxylase deficiency.

29. Clinical signs of PKU?

Intellectual disability, musty odor, seizures, eczema, fair skin/hair.

30. Mechanism of organ damage in galactosemia?

Accumulation of galactose-1-phosphate and galactitol.

31. Early signs of galactosemia?

Vomiting/diarrhea after milk intake, jaundice, hepatomegaly.

32. Fatal complication of galactosemia?

E. coli sepsis.

33. CF mutation?

CFTR gene mutation.

34. Why is sweat salty in CF?

Impaired Cl⁻ and Na⁺ reabsorption in sweat ducts.

35. Most serious organ complication in CF?

Lung disease from thick secretions and infections.

36. Why does CF cause pancreatic insufficiency?

Blocked ducts and abnormal bicarbonate transport cause acinar destruction.

37. Six diseases in newborn screening?

CH, CAH, PKU, G6PD deficiency, galactosemia, MSUD.

38. Why is newborn screening important?

Early detection prevents irreversible damage (e.g., intellectual disability).

1. A 3-day-old infant develops jaundice due to rapid breakdown of fetal RBCs and immature conjugation pathways. What physiologic condition explains this?

Physiologic neonatal jaundice

2. A premature infant born at 30 weeks develops respiratory difficulty hours after birth. What deficiency underlies this disorder?

Surfactant deficiency leading to Respiratory Distress Syndrome

3. A newborn of a diabetic mother develops seizures from low blood glucose shortly after delivery. What mechanism explains this?

Persistent fetal hyperinsulinemia causing postnatal hypoglycemia

4. A 5-day-old neonate presents with poor feeding, lethargy, and sepsis. What is the most common causative organism?

Group B Streptococcus

5. A neonate develops abdominal distention and bloody stools; X-ray shows air within the intestinal wall. What is this disease?

Necrotizing enterocolitis

6. An infant is born with macrosomia and congenital heart defects due to maternal hyperglycemia. What condition caused this?

Diabetic embryopathy

7. A premature infant has increasing oxygen requirements. CXR reflects reticulogranular “ground-glass” lungs. What pathology is forming inside the alveoli?

Hyaline membranes composed of fibrin and necrotic epithelial cells

8. A neonate with severe hemolysis develops diffuse edema, ascites, and pleural effusions. What condition is this?

Hydrops fetalis from hemolytic disease of the newborn

9. A Rh-negative mother becomes sensitized during her first pregnancy. Her next fetus develops severe anemia. What antibodies caused this?

Maternal anti-D IgG antibodies

10. A newborn with Rh hemolytic disease is at high risk for neurologic injury due to excess unconjugated bilirubin. What condition may develop?

Kernicterus

11. A small-for-gestational-age infant has symmetric growth restriction affecting all organs equally. What is the most likely cause?

Fetal intrinsic factors such as chromosomal abnormalities or congenital infections

12. An infant is growth-restricted but has preserved head circumference with small liver and reduced abdominal size. What mechanism explains this?

Uteroplacental insufficiency causing asymmetric FGR

13. A neonate develops cold stress, poor suck, and irregular respiration due to immature brainstem control. What underlying factor explains this?

Prematurity with incomplete neurologic maturation

14. A premature infant is unable to maintain temperature stability and shows poor vasomotor control. Which brain characteristic contributes to this?

Poor myelination and immature thermoregulatory centers

15. A neonate with congenital infection shows elevated cord-blood IgM levels. Why is this significant?

IgM is not normally synthesized by the fetus unless congenital infection is present

16. A neonate shows cataracts, deafness, cardiac defects, and microcephaly. What congenital infection most likely caused this?

Rubella infection (congenital rubella syndrome)

17. A newborn exposed to CMV in utero presents with microcephaly, deafness, and hepatosplenomegaly. What trimester carries greatest risk for this infection?

Second trimester

18. A fetus develops flattened facies, limb deformities, and pulmonary hypoplasia due to oligohydramnios. What sequence is this?

Potter sequence

19. A neonate shows extramedullary hematopoiesis, hepatosplenomegaly, and jaundice shortly after birth. What underlying process is causing this?

Severe hemolysis from immune-mediated RBC destruction

20. A mother taking retinoic acid for acne delivers a baby with craniofacial and cardiac defects. What developmental process was disrupted?

Retinoic acid–mediated regulation of TGF-β signaling during palatogenesis and organogenesis

21. A newborn has bilateral renal agenesis leading to anhydramnios and characteristic facial features. What directly causes the facial compression?

Absence of amniotic fluid restricting fetal movement

22. A newborn with congenital toxoplasmosis presents with chorioretinitis and hydrocephalus. What is the route of transmission?

Transplacental hematogenous spread

23. A neonate is born with pneumonia after inhaling infected amniotic fluid before birth. What type of infection is this?

Ascending (transcervical) infection

24. A premature infant develops recurrent apnea and requires CPAP therapy. What physiologic advantage does CPAP provide?

Prevents alveolar collapse by maintaining positive airway pressure

25. A neonate with HDN undergoes an exchange transfusion. What two physiologic problems does this correct?

Removes circulating antibodies and reduces unconjugated bilirubin

26. A newborn is extremely jaundiced within hours of birth but shows only mild anemia and spherocytes on smear. What type of hemolytic disease is this?

ABO hemolytic disease of the newborn

27. A very premature infant has unexpanded, red, “meaty” lungs on autopsy. What does this reflect?

Failure of alveolar expansion due to surfactant deficiency

28. A growth-restricted fetus shows decreased renal perfusion and reduced urinary output. What finding is expected on ultrasound?

Oligohydramnios

29. A neonate with congenital hypothyroidism shows severe developmental delay. What maternal factor could cause this?

Maternal hypothyroidism reducing fetal brain development

30. An infant dies suddenly during sleep without explanation. Autopsy reveals petechiae on pleura and epicardium. What syndrome is this?

Sudden Infant Death Syndrome (SIDS)