by Dr. Naveed Khan, MD

The Flu Shot

Dr. Ricardo Yazigi
Dr. Naveed Khan shares what you should know about the flu shot and other immunizations while TTC and pregnant.


With flu season in full swing, this time of year brings a lot of questions regarding flu shots and immunizations in general.  At all of our offices we support the recommendations by the American College of Obstetrics and Gynecology (ACOG) and the Centers for Disease Control and Prevention (CDC) for giving the influenza (flu) vaccine. All pregnant women and all women contemplating pregnancy or seeking pregnancy should get the flu vaccine. Ideally, the best time to get the flu vaccine is in the fall (October and November) since this gives the best protection for the peak of the flu season which is usually January through March. If one gets delayed in getting the flu shot, it is better to get the flu vaccine outside the optimal window than not get it at all. Getting the actual influenza infection may increase the risk for medical complications.

The flu vaccine is available in both an injectable and an intranasal option. The injectable vaccine is made up of an inactivated virus so it can be taken anytime while trying to conceive or if already pregnant. The intranasal vaccine is made of a live attenuated virus so it is not recommended for women who are already pregnant.

In the past, there used to be a concern regarding the use of thimerosol containing vaccines in pregnant women. Thimerosol is a preservative used in vaccines that was believed to be associated with some negative effects on offspring. Recent scientific evidence does not support any harmful effects on the children born to women taking immunizations containing thimerosol. Therefore, women can take vaccines containing thimerosol whether pregnant or while they are trying to conceive.

Immunizations & A Healthy Pregnancy

While there is no medical evidence to support the idea of immunizations impacting pregnancy, some women have a fear that immunizations could cause a miscarriage or result in a child with a birth defect.  Also, there are some physicians who are reluctant to immunize pregnant women because of worries that they could be wrongly blamed for a bad outcome resulting from a vaccination given by them.  The vast majority of vaccines are safe and recommended while pregnant. The only vaccines that should not be taken when pregnant are the MMR, Varicella, and herpes zoster but these are all fine preconceptually.

Some other routine vaccination questions that are commonly asked center on immunizations for rubella and varicella. In a woman who does not have evidence of immunity to varicella, the MMR (measles, mumps, and rubella) vaccine can be administered prior to pregnancy.  The varicella vaccine is given in two doses, given 1 month apart.  These vaccines are live attenuated vaccines, therefore, they should be taken prior to conception and pregnancy should be avoided for 1 month after the last dose.  There are also specific recommendations for immunizations for other infections such as hepatitis A, hepatitis B, meningococcus, Tetanus-Diphtheria (Td), and all the latest recommendations can be found on the CDC website.

Just as one prepares for pregnancy by leading a healthier lifestyle such as eating nutritiously, exercising, cessation of smoking and alcohol, one also needs to prepare for pregnancy by making sure one’s immunizations are up to date. Vaccinations in a mother are important because they help provide resistance to infections in the uterus and they provide passive immunity to the newborn. Ideally, immunizations, including the flu shot, should be done prior to conception, so it may be a good idea to make an appointment with your doctor to review your medical history to decide which immunization may benefit you specifically.

If you are been trying to conceive without success and would like more information or to schedule an appointment with one of the Shady Grove Fertility physicians, please speak with one of our New Patient Liaisons at 877-971-7755.