Infection During Pregnancy
The incidence of Zika virus infection in pregnant women is not known. We expect that the course of Zika virus disease in pregnant women is similar to that in the general population. No evidence exists to suggest that pregnant women are more susceptible or experience more severe disease during pregnancy. It is not known if pregnant women are more susceptible to Guillain-Barré syndrome. If a woman is infected during pregnancy, Zika can be passed to the fetus during pregnancy or around the time of birth. See the Health Effects page for information about health effects of infection during pregnancy.
There is limited information available about the risk of periconceptional Zika virus infection (defined as infection during 8 weeks before conception or 6 weeks before last menstrual period). Early case reports suggest there may be adverse outcomes associated with Zika virus infection in early pregnancy, including pregnancy loss and severe microcephaly. Information from other viral infections (e.g., cytomegalovirus) occurring around the time of conception indicate there are associations between periconceptional infections and adverse outcomes, although timing of infection and conception in these cases was often unknown.
- MotherToBaby: Refer Patients to Experts for CounselingExternal
- Vital Signs: Update on Zika Virus–Associated Birth Defects and Evaluation of All U.S. Infants with Congenital Zika Virus Exposure — U.S. Zika Pregnancy Registry, 2016 (MMWR, 2017)
- Vital Signs: Protecting Pregnant Women and Babies (April 2017)
- Zika virus and birth defects – Reviewing the evidence for causalityExternal (NEJM, 2016)
- Projecting Month of Birth for At-Risk Infants after Zika Virus Disease Outbreaks (EID, May 2016)
- MMWR Zika Reports