A 1-hour-old boy is evaluated in the newborn nursery for microcephaly. He was born via spontaneous vaginal delivery to a 26-year-old woman who did not receive prenatal care. The mother has no known chronic medical conditions. On physical examination, the boy's occipitofrontal circumference is 3 standard deviations below the mean. The anterior fontanelle is closed, and the skull is partially collapsed. Cardiopulmonary examination is normal. The abdomen is soft, nontender, and has no palpable masses. Multiple contractures and a right club foot are noted. The infant has marked hypertonia. Imaging shows thin cerebral cortices and multiple intracranial calcifications within the cerebral cortex. Which of the following maternal risk factors is most commonly associated with this infant's presentation?

Question

A 1-hour-old boy is evaluated in the newborn nursery for microcephaly.  He was born via spontaneous vaginal delivery to a 26-year-old woman who did not receive prenatal care.  The mother has no known chronic medical conditions.  On physical examination, the boy's occipitofrontal circumference is >3 standard deviations below the mean.  The anterior fontanelle is closed, and the skull is partially collapsed.  Cardiopulmonary examination is normal.  The abdomen is soft, nontender, and has no palpable masses.  Multiple contractures and a right club foot are noted.  The infant has marked hypertonia.  Imaging shows thin cerebral cortices and multiple intracranial calcifications within the cerebral cortex.  Which of the following maternal risk factors is most commonly associated with this infant's presentation?

Quizplus · Accepted Answer

11ec25c8_da95_0a02_bc81_97db3dd52c77_MD0003_00 This infant with severe microcephaly (occipitofrontal circumference >3 standard deviations below the mean) likely has congenital Zika syndrome. Zika virus can be transmitted via an Aedes mosquito bite or sexually transmitted from an infected partner. Women infected with Zika virus are frequently asymptomatic; however, during pregnancy, transplacental maternal-fetal viral transmission may occur and result in fetal disease. Zika virus preferentially destroys fetal neural progenitor cells, resulting in the abnormal brain development and neuronal destruction. Therefore, in addition to the severe microcephaly, infants typically have thin cerebral cortices with multiple intracranial calcifications (due to tissue necrosis). Additional clinical features include a closed anterior fontanelle (ie, craniosynostosis), multiple contractures, and hypertonicity. Diagnosis is confirmed with Zika virus reverse-transcriptase PCR performed in newborn serum, urine, or cerebrospinal fluid, and neuroimaging is performed in patients with confirmed disease to evaluate for abnormalities. Management of congenital Zika syndrome is supportive with continued evaluation of sequelae. Due to the risk of congenital Zika syndrome, precautions for pregnant women include avoiding travel to tropical, mosquito-infested regions. (Choice A) Consumption of unpasteurized dairy products is a risk factor for Listeria monocytogenes infection and congenital toxoplasmosis (unpasteurized goat milk). In utero L monocytogenes infection typically causes fetal demise or neonatal disseminated granulomatous disease. Congenital toxoplasmosis can cause intracranial calcifications; however, patients typically have hydrocephalus (rather than microcephaly) and chorioretinitis. (Choice B) Fetal alcohol syndrome occurs due to maternal alcohol consumption and can cause microcephaly; however, there is no associated craniosynostosis or skull collapse, making this diagnosis unlikely. Fetal alcohol syndrome (Choice C) Inadequate folic acid supplementation is a risk factor for fetal neural tube defects, including anencephaly. In contrast to microcephaly, those with anencephaly have a severe lack of cerebral cortex development, often with an associated open skin and skull defect that exposes the neural tissue, not seen in this patient. anencephaly (Choice D) A nonadherence to vaccination schedule is associated with an increased risk of congenital rubella syndrome, which can cause microcephaly; however, patients typically have a large anterior fontanelle, cataracts, and cardiac defects. Educational objective: Patients with congenital Zika syndrome typically have severe microcephaly associated with thin cerebral cortices and multiple intracranial calcifications. Congenital Zika syndrome can occur secondary to an infected Aedes mosquito; therefore, maternal travel to tropical, mosquito-infested regions should be avoided. References: Zika virus infection in pregnant women and microcephaly. (http://www.ncbi.nlm.nih.gov/pubmed/28575919) Zika virus-induced microcephaly and its possible molecular mechanism. (http://www.ncbi.nlm.nih.gov/pubmed/28081529) Progressive lesions of central nervous system in microcephalic fetuses with suspected congenital Zika virus syndrome. (http://www.ncbi.nlm.nih.gov/pubmed/27644020)

A 1-Hour-Old Boy Is Evaluated in the Newborn Nursery for Microcephaly