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.

Doctor going over document with pregnant woman.

Periconceptional Infection

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.

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