Mother to Baby during Pregnancy, Delivery, or Breast Feeding

I am pregnant. Am I at higher risk for getting infected with West Nile virus?

No. Pregnant women are not at higher risk for West Nile virus infection.

I am pregnant and was just diagnosed with West Nile virus infection. Is my baby at risk of infection?

A woman who is infected with West Nile virus during pregnancy can possibly transmit the virus to her baby, but the risk is low. Only a few cases of West Nile virus in newborns have been reported. Pregnant women should take precautions to reduce their risk for West Nile virus infection by avoiding mosquitoes, wearing protective clothing, and using insect repellent.

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If I am pregnant or breastfeeding, should I use insect repellents?

Yes. Protecting yourself from mosquito bites is the only way to prevent infection with West Nile virus. In addition to wearing protective clothing such as long-sleeve shirts and long pants, use insect repellents. Repellents containing active ingredients which have been registered with the EPA are considered safe for pregnant and breastfeeding women. More information about insect repellents is available here.

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Can West Nile virus be transmitted through breast milk?

Possibly. It appears that West Nile virus may be transmitted through breast milk, although this is likely a rare occurrence.

In 2002, a woman developed encephalitis due to West Nile virus from a blood transfusion she received shortly after giving birth. Laboratory analysis showed evidence of West Nile virus in breast milk collected from the mother soon after she became ill. She had been breastfeeding her baby and about 3 weeks after birth the infant tested positive for West Nile virus. Because of the infant’s minimal outdoor exposure, it’s unlikely that infection was from a mosquito. The infant had no symptoms of West Nile virus infection and remained healthy.

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Should I continue breastfeeding if I have West Nile virus disease?

Yes. The risk for West Nile virus transmission through breastfeeding is unknown. However, the health benefits of breastfeeding are well established. Therefore, there are no recommendations for a woman to stop breastfeeding because of West Nile virus illness.

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