A 2-day-old boy in the newborn nursery did not pass his hearing screening bilaterally. He was born at 37 weeks gestation by cesarean delivery due to labor complicated by minimal fetal heart rate variability and recurrent late decelerations. The mother had an ultrasound at 8 weeks gestation in the emergency department but did not have routine prenatal care. She had a brief febrile illness during her first trimester of pregnancy, followed by 5-7 days of joint pain that resolved without intervention. The infant's weight, length, and head circumference are

Question

A 2-day-old boy in the newborn nursery did not pass his hearing screening bilaterally.  He was born at 37 weeks gestation by cesarean delivery due to labor complicated by minimal fetal heart rate variability and recurrent late decelerations.  The mother had an ultrasound at 8 weeks gestation in the emergency department but did not have routine prenatal care.  She had a brief febrile illness during her first trimester of pregnancy, followed by 5-7 days of joint pain that resolved without intervention.  The infant's weight, length, and head circumference are <5th percentile.  Vital signs are normal.  The red reflex is absent bilaterally.  Cardiac examination reveals a loud, harsh murmur heard throughout systole and diastole over the left second intercostal space.  The liver and spleen are palpable on abdominal examination.  Which of the following is the most likely etiology of this infant's clinical presentation?

Quizplus · Accepted Answer

11ec25c8_d6cf_28af_bc81_332586d17426_MD0003_00 This small-for-gestational-age newborn with hearing loss and a cardiac defect in the setting of a maternal first-trimester illness likely has congenital rubella syndrome (CRS). In adults, rubella infection can be asymptomatic or characterized by mild symptoms (eg, fever, arthralgia, maculopapular rash). However, infection during pregnancy is dangerous due to the high risk of viral transmission through the placenta into fetal circulation. First-trimester infections are particularly threatening because they occur during organogenesis and can lead to either spontaneous abortion or CRS. The classic triad of CRS includes a harsh, machine-like, continuous (throughout systole and diastole) murmur of patent ductus arteriosus; sensorineural hearing loss; and leukocoria (white pupillary reflex) from cataracts. Other findings can include fetal growth restriction, hepatosplenomegaly, and a purpuric "blueberry muffin" rash. Diagnosis is confirmed by serology (positive infant IgM). Universal vaccination has reduced, but not eliminated, CRS. This mother was likely unvaccinated and nonimmune, a finding typically identified on prenatal screening. (Choices A and E) Both cytomegalovirus and toxoplasmosis can cause a mild, influenza-like maternal infection. However, congenital toxoplasmosis classically presents with chorioretinitis, hydrocephalus, and diffuse intracranial calcifications. Congenital cytomegalovirus infection can also lead to chorioretinitis and periventricular calcifications; cataracts and cardiac defects are not seen. (Choice B) Listeria monocytogenes can present as a nonspecific febrile illness in pregnant women. Transmission across the placenta can lead to fetal death (particularly with first-trimester infection) and premature birth. Newborn infection is typically severe with fever, disseminated abscesses in multiple organs (liver, spleen, lungs, kidneys, brain), and skin lesions, none of which are seen in this patient. (Choice C) In adults, parvovirus B19 can cause a mild febrile illness followed by arthralgias or arthritis. Infection during pregnancy (particularly gestational age <20 weeks) can lead to fetal loss or hydrops fetalis. However, congenital abnormalities are rare in surviving infants. (Choice F) Congenital syphilis (Treponema pallidum) can cause hepatomegaly, nasal discharge (snuffles), osteoarticular destruction, and a maculopapular rash. Heart defects are not seen, and sensorineural hearing loss is a late sequela of untreated congenital syphilis. Educational objective: Maternal-fetal transmission of the rubella virus is most teratogenic during the first trimester. The classic triad of congenital rubella syndrome includes sensorineural hearing loss, cardiac defects (eg, patent ductus arteriosus), and cataracts. References: Rubella and pregnancy: diagnosis, management, and outcomes. (http://www.ncbi.nlm.nih.gov/pubmed/25066688) Three cases of congenital rubella syndrome in the postelimination era-Maryland, Alabama, and Illinois, 2012. (http://www.ncbi.nlm.nih.gov/pubmed/23535689)

A 2-Day-Old Boy in the Newborn Nursery Did Not Pass