Pregnant women who are asymptomatic and have had potential exposure to the virus, but do not have ongoing exposure, are not recommended to be tested for Zika virus. However, the decision to test should be based on the "shared patient-provider decision-making model." Furthermore, certain jurisdictions might recommend that these women undergo testing based on “the epidemiology of Zika virus and other epidemiologic considerations.” The authors also noted that as the prevalence of the disease declines, “the updated recommendations for the evaluation and testing of pregnant women with recent possible Zika virus exposure but without ongoing exposure are now the same for all areas with any risk for Zika virus transmission.”
Pregnant women who report having been potentially exposed to Zika virus, who have a fetus with prenatal ultrasound findings that suggest congenital Zika virus syndrome, are recommended to receive both tests (NAT and IgM) “to assist in establishing the etiology of the birth defects.”
For certain scenarios, authors note that testing placental and fetal tissue specimens can be used for diagnostic purposes—such as for women who do not have a laboratory-confirmed diagnosis of Zika, but have an infant who may have potential associated birth defects. However, they point out that this is not a routine recommendation for pregnant women who are asymptomatic, have potentially been exposed to the virus (but do not have ongoing potential exposure), and have an infant who was born without evidence of potential associated birth defects.
Due to the fact that Zika virus IgM is no longer recommended for asymptomatic pregnant women who have ongoing potential exposure to the virus, Zika virus IgM “as part of preconception counseling to establish baseline IgM results for nonpregnant women with ongoing possible Zika virus exposure is not warranted.”
As the CDC reviews emerging evidence, they will continue to update their recommendations to incorporate what is learned. In the meantime, the CDC stresses that pregnant women should avoid any areas that put them and their child at risk for Zika virus infection. Furthermore, pregnant women should also be receiving counseling on preventive measures that can be taken to protect themselves and their child against the virus.
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