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  • Severe illness from newborns exposed to RSV during pregnancy is rare, but may occur.
  • Health experts recommend the maternal RSV vaccine during pregnancy to protect the pregnant person and fetus against severe respiratory infection.
  • If you contract RSV while pregnant, you may pass antibodies along to the fetus, which could offer protection once they’re born.

During the recent winter months cases of RSV rose quickly. Pregnant people may be particularly concerned about this rise in cases, and whether or not contracting RSV could impact their pregnancy.

Several vaccines are recommended during pregnancy to protect the pregnant person and developing fetus against severe illness.

The Center for Disease Control and Prevention (CDC) recommends the Tdap vaccine to protect against whooping cough, while COVID-19 and flu vaccines may help lower the risk of acute respiratory infection.

Pregnant people are also advised to receive the maternal RSV vaccine Abrysvo during the third trimester to protect their newborn against severe respiratory infection during the first few months of life.

Respiratory syncytial virus (RSV) is a common respiratory illness that may cause mild cold-like symptoms. While most people recover from RSV within a week or two, some people in high-risk groups, such as older adults, young children, and pregnant people, may experience complications from the virus.

Though rare, RSV infection during pregnancy could potentially pass to the fetus through the placenta. Here’s what you need to know.

The prevalence of pregnant people who contract RSV is not well established.

Dr. Maris K. Toland, an OB-GYN at Dartmouth Hitchcock Clinics in Bedford, NH, a part of Dartmouth Health, told Healthline that some research estimates between 10–13% of pregnant people may contract the virus.

Toland said that if a pregnant person contracts RSV, antibodies could potentially “pass trans-placentally to the fetus” and reduce the risk of RSV in infants once they’re born.

“It is [also] possible for vertical transmission of RSV infection through the placenta to the fetus potentially leading to poor outcomes, such as preterm birth or neonatal respiratory distress after birth,” she noted.

Indeed, a 2022 research review found that babies exposed to RSV during pregnancy had breathing difficulties after they were born. No miscarriages resulting from exposure to the virus were reported.

However, such complications are rare, especially among pregnant people who get immunized against the virus.

Dr. Patricia Faraz, board-certified OB-GYN at The Women’s Hospital at MemorialCare Saddleback Medical Center in Laguna Hills, CA,” told Healthline that in most cases, RSV is “not typically harmful to the fetus.”

“The reason to give RSV vaccines to pregnant women is so that the antibodies produced after receiving the vaccine cross the placenta and offer protection to the newborn and infancy period (6 months),” she explained.

“RSV infection in the mother is usually mild and self-limited. It’s rare to see severe infection in mothers.”

Toland agreed and noted that RSV infections are not usually serious in young, otherwise healthy adults.

In young children and older adults, however, Toland said RSV may cause “dangerous respiratory tract infections [and] can sometimes lead to pneumonia or hospitalization, particularly in people with pre-existing conditions like asthma or other lung conditions.”

RSV season runs from October to April in the northern hemisphere, but health experts recommend the maternal RSV vaccine year-round regardless of whether a person has previously contracted the virus.

The RSV shot is administered to pregnant people between 32–36 weeks gestation to protect newborns during the first 6 months of life. Another immunization, Beyfotus (nirsevimab), is a monoclonal antibody treatment given to newborns up to 8 months. It is not an RSV vaccine.

“Up to 80,000 infants can be infected with RSV yearly, requiring hospitalization,” Faraz said. “100–300 children will die each year from RSV,” she added, highlighting the importance of vaccinating against this respiratory virus.

As with any vaccine, however, the maternal RSV vaccine does not guarantee full protection for a pregnant person or infant once they’re born; it only protects against severe illness.

“[Abrysvo] does substantially reduce the risk of severe lower respiratory infection in the infant by 70–90%,” Faraz noted.

Toland added that Abrysvo may reduce an infant’s risk of being hospitalized from RSV infection by 57% in the first 6 months after birth.

Similar to vaccines that offer protection against respiratory illnesses like COVID-19 and the flu, the maternal RSV vaccine protects against severe illness — but that doesn’t always mean you won’t catch the virus.

RSV is spread through air droplets or direct contact with people who have the virus. You can reduce your risk of exposure with proper handwashing and wearing a mask for an added layer of protection.

As an extra precaution during pregnancy, you may also wish to avoid or limit contact with people exhibiting potential RSV symptoms resembling a mild cold, such as:

  • congestion
  • runny nose
  • fever
  • cough
  • sore throat

If a pregnant person contracts RSV, it is unlikely the virus will cause harm to a developing fetus or to a newborn infant after birth.

Some research, however, has shown a heightened risk of low birth weight and respiratory distress among newborns exposed to RSV in utero, but these complications are rare.

The CDC and other health experts recommend vaccinating against RSV during pregnancy to protect the mother and child against severe respiratory infection from the virus.

Only one RSV vaccine, Abrysvo, is approved for use in pregnant people during the third trimester.