A 25-year-old primigravida has a stillbirth at 18 weeks gestation. Her only symptom during pregnancy was pain in both knees and feet, which she attributed to pregnancy-related weight gain and being "on my feet all day" as an elementary school teacher. The pain lasted approximately a week and resolved without medication. The patient was taking prenatal vitamins daily, and her prenatal care was appropriate. Fetal autopsy shows pleural effusion, pulmonary hypoplasia, and ascites. Infection with which of the following is the most likely etiology of the stillbirth?

Question

A 25-year-old primigravida has a stillbirth at 18 weeks gestation.  Her only symptom during pregnancy was pain in both knees and feet, which she attributed to pregnancy-related weight gain and being "on my feet all day" as an elementary school teacher.  The pain lasted approximately a week and resolved without medication.  The patient was taking prenatal vitamins daily, and her prenatal care was appropriate.  Fetal autopsy shows pleural effusion, pulmonary hypoplasia, and ascites.  Infection with which of the following is the most likely etiology of the stillbirth?

Quizplus · Accepted Answer

Parvovirus is a nonenveloped single-stranded (ss) DNA virus with an increased incidence in children and teachers, as most individuals are infected during school outbreaks. Infection in adults can present with an acute, symmetric arthralgia/arthritis involving hands, wrists, knees, and/or feet, with or without rash. Fetal infection with parvovirus can lead to interruption of erythropoiesis, causing profound anemia and congestive heart failure. Fetal congestive heart failure can cause pleural effusions, pericardial effusions, and ascites. The findings on fetal autopsy (pleural effusion with secondary pulmonary hypoplasia, and ascites) represent fetal hydrops. Parvovirus is also responsible for erythema infectiosum ("fifth disease"), which presents with a "slapped cheek" appearance in children, and aplastic crisis in patients with sickle cell anemia. (Choice A) Varicella zoster virus (VZV) and cytomegalovirus (CMV) are examples of enveloped, double-stranded DNA viruses. VZV exposure in the second trimester increases the risk of fetal varicella syndrome (presents as limb hypoplasia, microcephaly, chorioretinitis). Congenital CMV can cause jaundice, hepatosplenomegaly, and periventricular calcifications. Congenital CMV (and other TORCH infections), when severe, can also cause hydrops due to multiorgan failure. However, parvovirus is the most common infectious agent causing hydrops and is especially likely given the mother's history of transient arthralgias during pregnancy. (Choice B) Rubella is an enveloped ssRNA virus. Congenital rubella infection characteristically causes cataracts, sensorineural deafness, and a "blueberry muffin" rash (purpuric lesions signify dermal erythropoiesis). (Choice C) Group B streptococcus (GBS) is a gram-positive coccus that is present in chains and colonizes the female genital and gastrointestinal tracts. Fetuses exposed to GBS via the amniotic fluid during labor, or with rupture of membranes, can develop sepsis a few days after birth. GBS exposure does not cause hydrops fetalis. (Choice E) Congenital toxoplasmosis leads to chorioretinitis, hydrocephalus, intracranial calcifications, microcephaly, and seizures. It is caused by an obligate intracellular protozoan, Toxoplasma gondii. Educational objective: Infection with parvovirus B19 (a nonenveloped single-stranded DNA virus) can cause arthralgia with or without rash in adults. An infected fetus may develop hydrops fetalis (severe anemia, heart failure, pleural effusions, pericardial effusions, and ascites). __________ References: Parvovirus B19 during pregnancy: a review. (http://www.ncbi.nlm.nih.gov/pubmed/22439064) Parvovirus B19 infection in human pregnancy. (http://www.ncbi.nlm.nih.gov/pubmed/21040396)

A 25-Year-Old Primigravida Has a Stillbirth at 18 Weeks Gestation