Ask the Expert

Q: I'll be pregnant during flu season, and I'm worried about having the flu vaccine. Is it safe?

A: Yes. That's why the U.S. Centers for Disease Control and Prevention recommend that healthy pregnant women get vaccinated against the flu no matter what trimester they are in. In fact, the American College of Obstetricians and Gynecologists call getting the flu shot an essential part of prenatal care. After all, pregnancy doesn't protect you against the flu, and it may even increase your risk of getting sick because of pregnancy-related changes in your immune system. Various studies also find that pregnant women may have a fourfold higher risk of death during a severe flu season and a much higher risk of hospitalization for flu-related complications. The risk is even higher if women have another health condition, such as asthma. The problem is, we don't know how severe a flu season will be until we're in the middle of it.

While we don't know for sure about the effect of the flu on your unborn baby, some studies suggest that it could lead to complications, including miscarriage, premature labor or, in some rare situations, birth defects.

The risk from the vaccine, however, is small. Very rarely, women may develop a low fever. The most common side effects are headache, fatigue and a reaction at the injection site—meaning your arm stays sore for a bit. None, however, are serious enough to outweigh the risks of the flu and the benefits of protecting yourself against it.

The few studies conducted on pregnant women receiving the flu vaccine find that their response to the vaccine is similar to that of women who are not pregnant. There is also good evidence that the vaccine can protect your baby during the first few months of life. That's very important because infants under six months should not receive the influenza virus.

One important point, though, is that you should only be vaccinated with the "inactivated virus" form of the vaccine, the type given in an injection. Stay away from the nasal spray vaccine, which uses an "attenuated" or modified version of a live flu vaccine.

Some women have questioned me about the use of a preservative used in flu vaccines called "thimerosal." They worry it could negatively affect their unborn baby. Thimerosal, an organic mercury compound, has been used since the 1930s in some vaccines, including the flu vaccine. Studies of more than 100,000 children followed from birth to more than seven years of age found no relationship between thimerosal vaccines and disorders like autism.

However, if you're still worried, just ask your health care professional for a thimerosal-free flu vaccine. Though this option was in limited supply in past years, there's an ample supply this flu season.

Bottom line? Yes, go talk to your health care professional about a flu vaccine. It's one of the few things in this world where you can get two for the price of one: One shot to protect two people!

--Ashley Roman, MD, MPH
Clinical Assistant Professor
Department of Obstetrics and Gynecology
New York University Langone Medical Center
NY, NY

References

ACOG Committee on Obstetric Practice. Influenza vaccination and treatment during pregnancy. ACOG Committee Opinion No. 305. American College of Obstetricians and Gynecologists. Obstet Gynecol. 2004;104:1125-1126.

Rasmussen SA, Jamieson DJ, Bresee JS. Pandemic influenza and pregnant women. Emerg Infect Dis [serial on the Internet]. January 2008. Available at: http://www.cdc.gov/EID/content/14/1/95.htm. Accessed September 18, 2008.

Mak TK, Mangtani P, Leese J, Watson JM, Pfeifer D. Influenza vaccination in pregnancy: current evidence and selected national policies. Lancet Infect Dis. 2008;8(1):44-52.

Zaman K, Roy E, Arifeen SE, et al. Effectiveness of Maternal Influenza Immunization in Mothers and Infants. N Engl J Med. 2008 [E-pub].

Q: I'll be breastfeeding during flu season. What happens if I get sick?

A: First, get a flu vaccine to protect yourself against this highly contagious disease. When you're breastfeeding, it's safe for you to get either the inactivate flu vaccine (the injection form) or the attenuated vaccine (the nasal spray form). There is no evidence that either form affects the safety of breastfeeding for you or your infant. Also, if you're concerned about thimerosal in flu shots, you should know that there are now flu vaccines available that do not contain this preservative.

We know, however, that flu isn't the only infectious disease you need to focus on when it come s to your and your baby's health. The U.S. Centers for Disease Control and Prevention (CDC) notes that all vaccines, other than the smallpox vaccine, are safe while you're breastfeeding. The added benefit of some of these vaccines is that they can also provide some protection to your baby because they are designed to protect against bacterial infections that may pass though your breast milk.

Breastfeeding is one of the best ways to get your infant off to a healthy start. Even if you only nurse your baby for a few days or weeks, that early milk, called colostrum, provides an important source of antibodies to protect against disease, as your baby's own immune system develops during his or her first year. Breastfeeding also has a number of benefits for you, including making it easier to lose those pregnancy pounds (you burn up to extra 500 calories a day nursing), returning your uterus to its pre-pregnancy size and reducing postdelivery bleeding.

But what if you do get sick while breastfeeding? It's important in most cases to continue breastfeeding because your baby will get protection against your illness from antibodies in your breast milk. In fact, with most viral infections, such as colds, sore throats and stomach viruses, you are infectious but starting to produce antibodies before you have any symptoms. So if you don't interrupt breastfeeding your baby gets protection both before you knew you were sick and throughout your illness. And don't worry; these common viruses are not passed to your baby through your milk.

If you really aren't up to nursing your baby for a feeding or two, ask if someone else can give your baby a bottle of expressed breast milk. You also should check with your health care provider to see what medications are available to help ease your symptoms, as many over-the-counter cold and flu remedies are safe for women who are breastfeeding. In the meantime, make sure to empty your breasts by nursing or pumping regularly so that they don't become hard and engorged as this can predispose a woman to develop mastitis, a painful breast infection. And, get some extra rest. If you do take a cold medicine, it could have drying effects, which are good for a drippy nose but mean you need to drink extra fluids so that your milk supply doesn't decrease.

And what if your baby gets sick? Breastfeeding is all the more important to continue if your baby is sick. In fact, you will need to breastfeed more often so your baby can get the fluids and nutrients he/she needs to replace those lost due to illness. Breastfeeding, always comforting to your baby, is even more so when he or she is sick. If your baby has a cold nursing him or her in an upright position may be helpful. Of course, you should talk to your baby's health care provider when your baby is ill if you have questions especially if he or she has a fever, diarrhea, is vomiting or won't breastfeed.

Make sure that you take extra care to wash your hands well (ideally, for the length of time it takes to recite the "ABCs" in your head) when any family member is ill. Oh, and one more thing—don't forget to get the rest of your family vaccinated so they don't bring the flu home and increase the risk of you or the baby getting it.

--Catherine Ruhl, CNM, MS
Associate Director, Women's Health Programs
Association of Women's Health, Obstetric and Neonatal Nurses (AWHONN)

The "Flu-Free and A Mom-to-Be" campaign is supported with an
educational grant from CSL Biotherapies.