2009 H1N1 Flu (Swine Flu)
Information for Pregnant and Breastfeeding Women

I’m pregnant. Should I get the H1N1 vaccine when it becomes available?

Yes. The Centers for Disease Control (CDC)’s Advisory Committee on Immunization Practices recommends that all women who are pregnant or planning to become pregnant during flu season get the H1N1 vaccine. This recommendation is made because pregnant women who get the flu are more likely to become very ill, may have severe respiratory complications, and are more likely to be hospitalized.

I have a fever and it feels like the flu but I’m not sure if it’s H1N1. Should I go to the hospital?

The CDC recommends that pregnant women who experience flu-like symptoms (fever, sore throat, cough, runny or stuffy nose, chills, fatigue, headache, achy muscles, diarrhea, vomiting) should contact a health care provider immediately. If you think you have a fever, take your temperature. This will help your health care provider when you contact him/her. If you have a doctor, call your doctor. If you do not have a doctor find an urgent care facility nearby. If your symptoms are severe or your condition worsens, go to the nearest emergency room. Pregnant women who are sick with H1N1 or who might be sick with H1N1 should be treated with antiviral medication as soon as possible.

I just found out that I am pregnant. Can I get the H1N1 vaccine during my first trimester?

Yes. The H1N1 vaccine is very similar to the seasonal flu vaccine which is recommended for use in any trimester. There is nothing new or experimental in the way the H1N1 vaccine is prepared. Because pregnant women who get the flu are at higher risk for developing serious complications and are more likely to be hospitalized, the CDC recommends that pregnant women be vaccinated with the H1N1 vaccine as soon as it becomes available. This means that women who are in their first trimester, second trimester or third trimester should receive the vaccine. Women who are planning a pregnancy during the flu season should also receive the H1N1 vaccine.

If I get the H1N1 vaccine do I still need to get a seasonal flu shot?

Yes. The CDC recommends that all pregnant women receive a seasonal flu shot in addition to the H1N1 vaccine. Even during a regular flu season pregnant women who become ill with the flu have a greater chance of developing complications. For this reason, the CDC recommends that pregnant women receive the seasonal flu shot developed for this year. This flu season, with the addition of the novel H1N1 flu virus, a vaccine targeted to protect against this new strain is also needed. Getting a seasonal flu shot in addition to the H1N1 vaccine is the best way to minimize the risk of infection. Pregnant women can receive the H1N1 vaccine and a regular flu shot at the same time.

If I already had my regular flu shot should I still get the H1N1 vaccine?

Yes. The CDC recommends that pregnant women receive both the regular flu shot and the H1N1 vaccine. The seasonal flu shot will not protect you from getting the H1N1 virus. The H1N1 influenza virus is a different strain than the influenza virus strains that were included in the seasonal flu vaccine for this year. For this reason the CDC recommends that all pregnant women be vaccinated for both the seasonal flu and H1N1 as soon as the vaccines become available.

I have the flu and my doctor wants me to take antiviral medication. Is it safe for pregnant women to use these medications?

The medications recommended for treating H1N1 infection are oseltamivir (Tamiflu) and zanamivir (Relenza). These medications are antivirals. Oseltamivir is the preferred medication for treatment in pregnancy because more of the drug is expected to get into the mother’s bloodstream. Antiviral medications are most effective if started within 48 hours of onset of symptoms. There is some information on the safety of antiviral medications in pregnancy. There is no evidence that these medications are harmful to the fetus when taken in any trimester of pregnancy. On the other hand, there is a clear risk of serious complications of the flu in pregnant women. For these reasons it is recommended that pregnant women infected with H1N1 be treated with an antiviral medication as soon as possible after onset of symptoms.

Is the H1N1 vaccine a “new” flu shot? Why can’t I get it with my regular flu shot?

No, this is not a new flu shot. The H1N1 vaccine is being produced in the same way seasonal flu vaccines have been produced for many years. There is nothing experimental or new being used to make the vaccine. If the H1N1 virus had emerged earlier, it would be part of the seasonal influenza vaccine for this year. In other words, there would be one flu shot and that flu shot would include the H1N1 virus. Next year it is expected that the H1N1 strain will be part of the seasonal flu vaccine and only one vaccination will be required to protect people from both seasonal flu viruses and the H1N1 virus.

I haven’t had my regular flu shot yet. Is it safe to get the H1N1 vaccine and the regular flu shot at the same time?

Yes. In a case where a pregnant woman is to receive both vaccines on the same day the CDC recommends using different places on the body to inject the vaccines.

I have heard pregnant women should not get certain types of flu vaccines? Is this true?

Yes, there are vaccines that are not recommended for pregnant women. The intranasal flu vaccine (FluMist) is a live, attenuated vaccine. The injectable flu vaccine contains inactivated virus. For this reason the CDC recommends that pregnant women not receive FluMist.

Will the H1N1 vaccine contain thimerosal?

Some forms of both seasonal and the H1N1 vaccines will contain thimerosal. Thimerosal is a preservative used in some vaccines. There is no evidence to date that thimerosal poses a risk to the developing fetus. However, for those who wish to avoid thimerosal in pregnancy, there will be thimerosal-free vaccine available for both seasonal flu and H1N1. Consult with your health care provider for more information.

I already had the flu. Do I still need to get a flu shot?

The CDC recommends that all pregnant women receive both the seasonal flu vaccine and the H1N1 vaccine even if they have had a flu-like illness earlier this year. It is possible to get sick with one flu virus strain and then get sick with another flu virus strain later. This is why all pregnant women are strongly encouraged to get both the seasonal flu vaccine and the H1N1 vaccine.

I have been sick with the flu for several days and I just saw a doctor. They want me to take drugs for the flu. Should I still take them even though I’ve been sick already? Would it do any good?

The CDC recommends treatment, preferably with osetlamivir (Tamiflu), even if a pregnant woman has been sick for a few days. It is best if a woman can receive the antiviral medication within 48 hours of experiencing symptoms. However, the medication may be helpful even if it is started more than 48 hours after onset of the first symptoms of the flu.

When and where can I get the H1N1 vaccine? Can I go to my doctor or do I need to go somewhere else?

The H1N1 vaccine is expected to be available in the fall. It will be available at doctors’ offices, health departments and in some neighborhood pharmacies.

I am not pregnant but we are trying. Do I still need to get the H1N1 vaccine? Will it make it harder to get pregnant if I get the vaccine?

The CDC recommends that all women who are pregnant or who may become pregnant during the flu season get the H1N1 vaccine. If you plan on being pregnant during the flu season and become infected after you are pregnant, this means you would be more vulnerable to complications of the flu. For this reason, it is recommended that women who are planning a pregnancy receive the H1N1 vaccine. There is no evidence that flu vaccines in general or the H1N1 vaccine in particular would make it more difficult to get pregnant. There is no evidence that men who receive a seasonal flu vaccine or the H1N1 vaccine would have problems with fertility.

I am breastfeeding. Do I need to stop breastfeeding if I get the H1N1 vaccine?

No. The CDC recommends that women continue to breastfeed after receiving the H1N1 vaccine. Infants under 6 months old cannot receive the H1N1 vaccine. However, infants are susceptible to infection with the H1N1 virus. For this reason people that care for infants under 6 months old are encouraged to get the H1N1 vaccine. This will help protect infants from getting sick with the H1N1 virus.

For more information about H1N1

In California, contact  800-532-3749

Visit the Center for Disease Control 2009 H1N1 Flu (Swine Flu) website

Download the H1N1 Flu (Swine Flu) Factsheet, the H1N1 Flu Vaccine, the Seasonal Influenza and Vaccine duing Pregnancy Factsheet and the Antiviral Medications to Treat/Prevent Influenza (Flu) and Pregnancy Factsheet

For residents outside of California but in the US or Canada:
Contact the Organization of Teratology Information Services

For residents outside the United States or Canada:

Contact the European Network of Teratology Information Services.