Zika Virus Potentially Linked with Miscarriage

Pregnant women or women planning to become pregnant concerned about the effects of Zika on their health as well as the health of their unborn children have another potential complication to worry about: miscarriages.

A report published in the “correspondence” section of the New England Journal of Medicine on September 8 described the case of a woman who had a miscarriage following Zika virus infection. The authors of the report note that Zika was detected in the fetal tissue and that viremia lasted for at least 21 days.

According to the report, a 31-year-old woman who was 10 weeks pregnant presented to the authors’ outpatient clinic in Rotterdam, the Netherlands, with a 2-day history of headache, mild arthralgia in both wrists and the left knee, and a pruritic, macular rash on the trunk and both arms. She began experiencing these symptoms the day following her return from a trip to Suriname. The woman reported that she did not use malaria chemoprophylaxis or personal protective measures, such as insect repellents, during her trip. Physical examination revealed normal vital-sign measurements and an absence of fever, and the patient’s joints were not visibly swollen or warm but were mildly painful with movement. The physicians collected blood and urine samples at regular intervals following the initial exam.

Up until her presentation with Zika symptoms, the patient’s medical history had been uneventful, as had been her pregnancy. She had received routine vaccines according to currently accepted guidelines in Suriname, where she had lived until her early 20s. The World Health Organization reports that the South American country, which borders on Brazil (ground zero for Zika), has averaged more than 200 new cases of infection per week over the course of this year.

The authors did not respond to requests for comment; however, in their report, they write that the patient’s symptoms “resolved spontaneously” after 6 days and that, 14 days after symptom onset, ultrasonography performed at a routine prenatal screening visit (estimated gestational age, 11 weeks and 4 days) revealed no fetal heartbeat. A week later, physicians performed amniocentesis, dilation, and curettage, and collected samples of amniotic fluid and fetal and placental tissue for further laboratory analysis. The amniotic fluid and fetal and placental tissue tested positive for Zika on RT-PCR assays and cell-culture isolation, and results were confirmed via whole-genome sequencing. Furthermore, serum and urine samples obtained from the patient were positive for Zika on RT-PCR at multiple time points, including 21 days after symptom onset, even though urine samples were negative after day 12. The authors reported that neutralizing antibody titers against Zika “more than quadruple[ed]” between days 2 and 12. By day 28, Zika virus RNA was undetectable in serum specimens.

In their report, they noted, “The findings on histopathological analysis of placental tissue specimens were consistent with intrauterine fetal death 1 week before curettage was performed… [and] placental amniotic epithelium was positive for [Zika virus] RNA. In addition, positive staining of fetal mesenchymal cells with affinity for perichondrium was observed. Because of autolysis, no recognizable fetal brain tissue was present… Our observation indicates that [Zika virus] replicates in pluripotent (amniotic stem) cells involved in early-stage embryo development.”

To date, a handful of studies have linked fetal death with Zika virus infection.

Brian P. Dunleavy is a medical writer and editor based in New York. His work has appeared in numerous healthcare-related publications. He is the former editor of Infectious Disease Special Edition.