Influenza Vaccine in Pregnancy
The short answer
The flu shot is recommended for all pregnant people during any trimester of pregnancy. Pregnant people are at higher risk for severe flu complications due to immune system and cardiopulmonary changes. The inactivated flu vaccine is safe and protects both you and your baby (through transferred antibodies) during the first months of life. The nasal spray flu vaccine should NOT be used during pregnancy.
This is one of the most common questions parents ask. Searching for answers means you care.
By Age
What to expect by age
The flu shot can be given at any point during pregnancy, including the first trimester. The inactivated flu vaccine does not contain live virus and is safe. Getting vaccinated early in flu season protects you throughout your pregnancy. The flu during pregnancy increases risk of preterm labor, hospitalization, and ICU admission.
Getting the flu shot in the third trimester provides maximum antibody transfer to the baby, who will be protected during their first months of life before they can be vaccinated. If flu season begins during your third trimester, get vaccinated as soon as the vaccine is available.
What Should You Do?
When to take action
- Sore arm and mild fatigue for 1-2 days after vaccination
- Getting the flu shot during any trimester
- You have a severe egg allergy (most flu vaccines are egg-free or low-egg now)
- You had a previous allergic reaction to a flu vaccine
- You have questions about flu vaccine safety during pregnancy
- Flu symptoms during pregnancy (fever, cough, body aches) - antivirals like oseltamivir (Tamiflu) are recommended early
- High fever during pregnancy - contact your provider same day
Sources
Related Resources
Trust your instincts. If something feels wrong, reach out to your pediatrician.
Worrying about your baby means you care. That is a good thing.
Related Maternal Concerns
Tdap Vaccination During Pregnancy
The Tdap vaccine (tetanus, diphtheria, and pertussis/whooping cough) is recommended during every pregnancy, ideally between weeks 27-36 of the third trimester. This allows the birthing parent to produce antibodies that cross the placenta, protecting the newborn from pertussis during their first vulnerable months before they can receive their own vaccines.
COVID Vaccination During Pregnancy
COVID-19 vaccination is recommended during pregnancy by ACOG, CDC, and other major health organizations. COVID-19 infection during pregnancy significantly increases the risk of severe illness, ICU admission, preterm birth, and stillbirth. The mRNA vaccines (Pfizer, Moderna) have been extensively studied in pregnant people and shown to be safe and effective.
Dealing with Abnormal Prenatal Screening Results
An abnormal prenatal screening result can be terrifying, but it is important to understand that screening tests are designed to cast a wide net and have significant false-positive rates. Most people with abnormal screening results go on to have healthy babies after further testing confirms the baby is fine. An abnormal screening is a reason for more information, not a diagnosis.
Pregnancy Over 35 (Advanced Maternal Age)
While pregnancy after 35 carries some increased risks (including chromosomal abnormalities, gestational diabetes, and hypertension), the vast majority of people over 35 have healthy pregnancies and healthy babies. The term "geriatric pregnancy" is outdated and does not reflect reality. With appropriate prenatal care and monitoring, outcomes are excellent.
Amniocentesis Questions and Fears
Amniocentesis is a diagnostic test performed between 15-20 weeks that analyzes amniotic fluid to detect chromosomal conditions and genetic disorders with over 99% accuracy. The risk of pregnancy loss from the procedure is approximately 1 in 500-1,000 when performed by an experienced provider. Understanding the actual risks can help you make an informed decision.
20-Week Anatomy Scan Unexpected Findings
The 20-week anatomy scan checks your baby's major organs, structures, and growth. Most scans are completely normal. When unexpected findings are identified, they range from minor variants that resolve on their own to conditions that need further evaluation. Many findings require nothing more than a follow-up ultrasound to confirm the baby is developing well.