Why Flu Vaccination During Pregnancy Is Essential for Maternal and Infant Health

Pregnancy places women in a uniquely vulnerable position when it comes to seasonal influenza (flu). Changes in the immune, respiratory, and cardiovascular systems increase the risk of severe illness, hospitalization, pneumonia, and adverse pregnancy outcomes if a flu infection occurs.¹ These effects do not stop at the mother—flu infection during pregnancy has been associated with preterm birth, low birth weight, and, in rare cases, fetal loss.

One of the best and most reliable ways to protect pregnant patients and their infants is by flu vaccination. Several professional organizations, such as the Centers for Disease Control and Prevention (CDC) and the American College of Obstetricians and Gynecologists (ACOG), recommend annual flu vaccination for all individuals who are or will be pregnant during flu season, regardless of trimester.²

Maternal Protection and Reduced Disease Severity

Pregnant women are significantly more likely to experience severe flu complications compared with their nonpregnant counterparts. Hospitalization rates are notably higher, and respiratory compromise can be more severe due to the physiologic demands of pregnancy.¹

Vaccination offers strong protection against these outcomes. In several observational studies, flu vaccination during pregnancy has been linked to a significant reduction in hospitalizations and emergency visits for flu.³ If an infection occurs, the severity of the disease is reduced by maternal immunization; thus, hospital stays are shorter, and the number of intensive care unit (ICU) admissions is lower.

Vaccination may be administered in any trimester without affecting safety or efficacy. The main reason for early vaccination—ideally by the end of October—is to provide maternal antibody production before the time of flu peak, though vaccination later in the season still confers meaningful protection.

Passive Immunity and Infant Health Benefits

One of the most significant benefits of maternal flu vaccination is the passive immunity it provides to infants. As children under 6 months of age cannot be vaccinated against the flu, they have to rely on the antibodies that their mother has passed on to them via the placenta and also through breast milk.³

Research consistently confirms that infants of immunized moms are less likely to catch the flu and require hospitalization during their first 6 months of life.³ A large analysis found that getting the vaccine during pregnancy cut the chance of an infant needing hospital care due to flu by as much as 72%.⁴ This safeguard is quite instrumental in the period of early infancy when the danger of going to the hospital due to severe flu is at its peak.

Safety and Reassurance for Expectant Mothers

Safety concerns are a common reason for vaccine hesitancy among pregnant women, but extensive research demonstrates that inactivated flu vaccines are safe for both mother and fetus.¹ Large cohort studies have found no increased risk of miscarriage, preterm birth, congenital anomalies, or other adverse pregnancy outcomes following flu vaccination.¹

Vaccination during pregnancy has no harmful effects on fetal growth or development. Preventing maternal flu infection helps reduce risks associated with high fevers and systemic illness, which can otherwise complicate pregnancy.²

Improving Uptake

Despite strong evidence and clear recommendations, vaccination uptake among pregnant individuals remains suboptimal.³ Pharmacists are in a key position to close this gap. As trusted healthcare providers and frequent points of contact, pharmacists can counsel pregnant patients about the benefits and safety of flu vaccination, dispel myths, and provide convenient immunization opportunities.

Clear communication—emphasizing that the vaccine protects both mother and baby, can be given during any trimester, and carries no significant safety risks—can meaningfully improve vaccination rates and maternal-infant outcomes.

Conclusion

Flu vaccination during pregnancy is a simple yet powerful tool to protect maternal and infant health. It significantly reduces the risk of severe maternal illness, provides vital passive immunity to newborns, and is supported by extensive safety data. With pharmacists playing a proactive role in patient education and vaccine delivery, more families can benefit from this critical preventive measure.

REFERENCES

1. The flu vaccination in pregnancy - Sandy Lane Surgery. Sandy Lane Surgery. Published October 9, 2025. Accessed October 15, 2025. https://www.sandylanesurgery.org.uk/2025/10/09/the-flu-vaccination-in-pregnancy/

2. DHHS: DPH: NC Flu: Providers: Guidance for Pregnant Women. Ncdhhs.gov. Published 2025. Accessed October 15, 2025. https://flu.ncdhhs.gov/providers/pregnant.htm

3. Pregnant Women & Influenza (Flu). CDC. Published 2019. https://www.cdc.gov/flu/highrisk/pregnant.htm

4. CDC. Influenza (Flu). Centers for Disease Control and Prevention. Published 2019. https://www.cdc.gov/flu

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