The influenza vaccine is recommended for pregnant individuals. Understanding current recommendations and supporting evidence helps individuals make informed decisions about their health and their baby’s well-being.
Why Flu Vaccination is Important During Pregnancy
Pregnancy causes changes in the immune system, heart, and lungs, making pregnant individuals more susceptible to severe influenza. Complications like pneumonia are more likely, and pregnant individuals are more prone to hospitalization from flu compared to non-pregnant individuals.
Influenza infection during pregnancy can also affect the developing baby. Complications such as preterm birth, low birth weight, and in some cases, stillbirth, have been associated with flu during pregnancy. A common flu symptom, fever, has been linked in some studies to neural tube defects and other adverse outcomes for the developing baby.
Receiving the flu vaccine during pregnancy offers a protective benefit to the newborn. Antibodies developed by the pregnant individual are transferred through the placenta to the baby, providing passive immunity. This is particularly valuable because infants younger than six months are too young to receive their own flu vaccination.
Safety Profile of the Flu Shot for Pregnant Individuals
The flu shot is considered safe and is recommended during any trimester of pregnancy by major health organizations, including the Centers for Disease Control and Prevention (CDC) and the American College of Obstetricians and Gynecologists (ACOG). Millions of pregnant individuals have safely received the flu shot over more than 50 years.
Extensive research and monitoring support the safety of the flu vaccine for both the pregnant person and the baby. Reviews of reports to the Vaccine Adverse Event Reporting System (VAERS) have found no evidence linking flu shots to pregnancy complications or adverse fetal outcomes. Large studies using data from the Vaccine Safety Datalink (VSD) found no increased risk for spontaneous abortion (miscarriage) or stillbirth after flu vaccination during pregnancy.
The flu shot contains an inactivated (killed) virus, meaning it cannot cause influenza illness. This distinguishes it from the live attenuated nasal spray flu vaccine, which is not recommended during pregnancy. Studies have also found no increased risk of birth defects associated with the flu shot.
Addressing Common Questions and Concerns
One common concern relates to thimerosal, a mercury-containing preservative used in trace amounts in some multi-dose flu vaccine vials. Thimerosal is not harmful in the small doses found in vaccines and is processed differently and excreted more rapidly from the body than other forms of mercury. Many flu vaccines are available in single-dose presentations that do not contain thimerosal as a preservative. Health organizations state that the flu shot, with or without thimerosal, is safe for pregnant individuals.
Side effects from the flu shot are generally mild and temporary, similar to those experienced by non-pregnant individuals. These can include soreness, redness, or swelling at the injection site, headache, muscle aches, or a low-grade fever. These reactions are typically less severe than the symptoms of influenza itself.
The flu vaccine is effective in reducing the risk of flu illness and related complications. A 2018 study showed that getting a flu shot during pregnancy reduced the risk of flu-related hospitalization by an average of 40%. Another study indicated that vaccination reduced the risk of flu-associated acute respiratory infection during pregnancy by up to half.
Practical Advice for Vaccination During Pregnancy
It is recommended that pregnant individuals receive the flu shot as soon as it becomes available each season, ideally by the end of October. However, vaccination remains beneficial throughout the entire flu season, which typically runs from October to May. The vaccine can be administered at any point during pregnancy, in any trimester.
The inactivated influenza vaccine, given as a shot, is recommended for pregnant individuals. Flu shots are widely available at healthcare provider offices, pharmacies, and community vaccination centers. It is safe to receive the flu vaccine at the same time as other recommended vaccines during pregnancy, such as the Tdap (tetanus, diphtheria, and pertussis) vaccine. This ensures comprehensive protection for both the pregnant individual and the baby.