A 1-day-old boy is admitted to the neonatal intensive care unit due to macrocephaly and jaundice. The patient was born by spontaneous vaginal delivery at 41 weeks gestation to a 38-year-old woman, gravida 4 para 3 (2 live vaginal births and a first-trimester miscarriage), who had consistent prenatal care. The mother traveled to central Africa during the first trimester. While there, she developed fever that lasted 2 weeks along with swollen lymph nodes and muscle aches that resolved spontaneously. The patient's weight and length are at the 25th percentile; head circumference is above the 97th percentile. Vital signs are normal. Diffuse jaundice is noted on examination. The liver is palpable 4 cm below the costal margin. Heart and lung sounds are normal on auscultation. CT scan of the head reveals hydrocephalus and diffuse intracranial calcifications. Laboratory results include total bilirubin 7.2 mg/dL and direct bilirubin 5.5 mg/dL. Which of the following maternal exposures most likely resulted in this patient's condition?

Question

A 1-day-old boy is admitted to the neonatal intensive care unit due to macrocephaly and jaundice.  The patient was born by spontaneous vaginal delivery at 41 weeks gestation to a 38-year-old woman, gravida 4 para 3 (2 live vaginal births and a first-trimester miscarriage), who had consistent prenatal care.  The mother traveled to central Africa during the first trimester.  While there, she developed fever that lasted 2 weeks along with swollen lymph nodes and muscle aches that resolved spontaneously.  The patient's weight and length are at the 25th percentile; head circumference is above the 97th percentile.  Vital signs are normal.  Diffuse jaundice is noted on examination.  The liver is palpable 4 cm below the costal margin.  Heart and lung sounds are normal on auscultation.  CT scan of the head reveals hydrocephalus and diffuse intracranial calcifications.  Laboratory results include total bilirubin 7.2 mg/dL and direct bilirubin 5.5 mg/dL.  Which of the following maternal exposures most likely resulted in this patient's condition?

Quizplus · Accepted Answer

11ec25c8_d6d7_b33e_bc81_7d2569ca0ead_MD0003_00 This infant has features of congenital toxoplasmosis due to transplacental transmission of Toxoplasma gondii. Characteristic findings in a symptomatic infant include hydrocephalus and diffuse intracranial calcifications; chorioretinitis is also classic. Although toxoplasmosis is often associated with microcephaly due to brain atrophy, hydrocephalus can lead to macrocephaly in some patients, as seen in this neonate. Nonspecific findings of congenital infection include jaundice, cholestasis, and hepatomegaly, also seen in this patient. The pathogenesis of toxoplasmosis, which is prevalent in warm, humid environments (eg, central Africa), begins with shedding of protozoan oocysts in the feces of infected cats (definitive hosts). The oocysts contaminate soil and water and are ingested by other animals. Pregnant women acquire the infection by either inadvertent ingestion of cat feces (eg, contaminated kitty litter) or consumption of unwashed produce or raw or undercooked meat from infected animals. Maternal infection may be asymptomatic or cause a self-resolving illness with fever, myalgias, lymphadenopathy, and/or rash. First-trimester infection is more likely to result in severe, symptomatic neonatal infection. (Choice A) Syphilis, hepatitis B, and HIV are common congenital infections that can be transmitted sexually. None of these infections is associated with the type of intracranial lesion seen in this patient. (Choice B) A pregnant woman can transmit parvovirus or rubella infection to the fetus after exposure to infected respiratory droplets. Unlike congenital toxoplasmosis, congenital parvovirus causes severe fetal anemia (eg, pallor, tachycardia) and hydrops fetalis (eg, edema, pleural/pericardial effusions). Although congenital rubella can also cause hepatomegaly and jaundice, the classic features of cataracts, sensorineural hearing loss, and congenital heart disease would be expected. Intracranial calcifications are not seen in either parvovirus or rubella. (Choice C) Zika virus and malaria are prevalent in Africa and could have been acquired by the mother via mosquito bite. However, congenital Zika virus infection causes severe microcephaly (not macrocephaly), and congenital malaria typically presents with fever, anemia, and splenomegaly, not intracranial calcifications. (Choice D) Saliva is the most common source of cytomegalovirus (CMV) infection. In contrast to T gondii infection, in which diffuse intracranial calcifications are caused by direct parenchymal infection, CMV is associated with periventricular calcifications due to germinal matrix bleeds. In addition, CMV causes microcephaly. periventricular calcifications Educational objective: Congenital toxoplasmosis classically presents with hydrocephalus and diffuse intracranial calcifications. Maternal acquisition of toxoplasmosis is due most commonly to ingestion of cat feces or undercooked meat from animals infected with Toxoplasma gondii. References: Toxoplasmosis in the fetus and newborn: an update on prevalence, diagnosis and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/22943404)

A 1-Day-Old Boy Is Admitted to the Neonatal Intensive Care