Influenza is often thought of as a bad cold, but in pregnancy it carries a higher risk of serious complications. For this reason, the WHO and obstetric organisations, including the Federation of Obstetric and Gynaecological Societies of India, recommend influenza vaccination for pregnant women. Many expectant mothers still have understandable questions about safety. This article reviews what the evidence says about the flu vaccine during pregnancy and how it protects both mother and newborn.

What Is Influenza, and How Is It Different from a Cold?

Influenza is an acute respiratory infection caused by influenza A and B viruses. It spreads through droplets and contaminated surfaces, with an incubation period of one to four days.
Unlike a common cold, flu usually begins abruptly with high fever, chills, myalgia, headache, dry cough and marked fatigue. In North India, influenza activity typically peaks in winter, with a second rise during the monsoon in some regions.

The flu vaccine used in pregnancy is an inactivated vaccine, given as an intramuscular injection. It contains killed virus or purified viral proteins and cannot cause influenza.

Why Are Pregnant Women at Higher Risk from Flu?

Pregnancy brings changes that increase vulnerability:
●    Immune modulation: Adjustments to prevent rejection of the foetus alter responses to viral infections.
●    Respiratory changes: The enlarging uterus raises the diaphragm and reduces functional residual capacity.
●    Cardiovascular load: Increased heart rate, cardiac output and oxygen consumption reduce reserve during illness.

Pregnant women with influenza have higher rates of hospitalisation, pneumonia and intensive care admission than non-pregnant women of similar age. The risk increases further in the second and third trimesters and with conditions such as asthma, diabetes, heart disease, obesity and immunosuppression.

For the baby, severe maternal flu is associated with preterm birth and low birth weight. High maternal fever in early pregnancy has been linked to neural tube defects and other congenital anomalies.

What Are the Symptoms of Flu in Pregnancy?

Symptoms include sudden fever, chills, dry cough, sore throat, nasal congestion, muscle aches, headache and severe tiredness. Vomiting or diarrhoea may occur. Warning signs of complications include breathlessness, chest pain, persistent high fever, confusion and bluish lips.

How Is Influenza Diagnosed?

During flu season, diagnosis is often clinical. Nasopharyngeal or throat swabs tested by rapid antigen tests or RT-PCR can confirm influenza. Treatment in pregnant women should not be delayed while waiting for results if flu is strongly suspected.

How Is Flu Treated During Pregnancy?

Antiviral treatment with oseltamivir is recommended for pregnant women with suspected or confirmed influenza, ideally started within 48 hours of symptom onset, though it is still beneficial later in severe illness. It is usually given as a five-day course and is considered appropriate in pregnancy.
Supportive care includes rest, hydration and paracetamol to control fever. Fever should be actively treated in pregnancy rather than left to run its course.

What Does the Evidence Say About Influenza Vaccine Safety During Pregnancy?

Research on influenza vaccine safety during pregnancy spans decades and includes large observational studies and randomised trials. Key findings:
●    Inactivated influenza vaccine can be given in any trimester.
●    Studies have not found an increased risk of miscarriage, stillbirth, congenital anomalies or preterm birth linked to vaccination.
●    Some studies suggest vaccinated mothers have lower rates of preterm birth and low birth weight during flu season, though findings vary.
●    Live attenuated influenza vaccine, given as a nasal spray, is not recommended during pregnancy.
●    Egg allergy is no longer considered a contraindication under current guidance, though a history of severe allergic reaction to a previous flu vaccine is.
Common side effects include pain or redness at the injection site, low-grade fever, fatigue and muscle aches for one to two days.

How Does Maternal Flu Vaccination Protect the Newborn?

Infants cannot receive influenza vaccine until six months of age, yet they have the highest risk of hospitalisation from flu among children. Maternal vaccination leads to production of IgG antibodies, which cross the placenta actively, particularly in the third trimester. Randomised trials have shown that maternal vaccination reduces laboratory-confirmed influenza in infants during the first months of life. Antibodies in breast milk may provide additional protection.

Should Pregnant Women Take the Flu Vaccine Before Winter?

Yes, where possible. Protective antibody levels develop about two weeks after vaccination. Vaccinating in autumn, before seasonal activity rises in North India, offers the best coverage. Vaccination later in the season is still worthwhile.
The vaccine composition is updated annually based on WHO recommendations for circulating strains, so a new dose is needed each season.

Can I Get a Flu Vaccine While Pregnant?

Most pregnant women can. Inform your doctor about any previous severe allergic reaction to a flu vaccine or its components, or a history of Guillain-Barré syndrome within six weeks of an earlier flu vaccine. Vaccination may be postponed during a high fever, but a mild cold is not a reason to delay.
The influenza vaccine can generally be given at the same visit as the Tdap vaccine if the timing suits both.
Women looking for a pregnancy vaccination doctor in Jaipur should discuss their vaccination history and schedule with their obstetrician.

When Should a Pregnant Woman See a Doctor for Flu Symptoms?

Contact your doctor promptly if you develop fever with cough or body ache. Seek urgent care for breathing difficulty, chest pain, persistent high fever, confusion, reduced foetal movements, contractions or leaking fluid.

How Else Can Pregnant Women Prevent Flu?

Alongside vaccination, practise regular handwashing, avoid close contact with unwell people, wear a mask in crowded indoor settings during flu season, and encourage household members to be vaccinated. Adequate sleep, nutrition and hydration support recovery if infection occurs.

Conclusion

Influenza vaccination is one of the most effective ways to protect both mother and newborn during flu season. The evidence on safety is reassuring and is backed by major health organisations. If you are pregnant and winter is approaching, discuss the flu vaccine during pregnancy with your obstetrician at your next antenatal visit. Maternite Hospitals provides obstetrics and gynecology care to help expectant mothers plan a safe vaccination schedule.