Patient education: Vaccination during pregnancy (Beyond the Basics)

INTRODUCTION — 

Vaccines are a way of teaching your body to fight germs (eg, viruses or bacteria) that cause infections. Thanks to vaccines, fewer people get seriously ill or die from infections now than in the past. When a person gets a vaccine, this is called "vaccination" or "immunization."

Vaccines work by stimulating your body to produce an immune response. This includes making antibodies that can help fight infections and prevent you from getting sick when infected. Some vaccines are safe to receive during pregnancy, while others should not be given while you are pregnant, and instead be given at least one month before getting pregnant or after your baby is born. Certain vaccines are recommended for all pregnant people, while others may be recommended only for persons with certain medical conditions or risk for a particular infection.

General recommendations for vaccination in adults are discussed separately. (See "Patient education: Vaccines for adults (Beyond the Basics)".)

VACCINES RECOMMENDED BEFORE PREGNANCY — 

Anyone planning pregnancy should have received all routine vaccinations recommended by the Advisory Committee on Immunization Practices (ACIP) of the United States Centers for Disease Control and Prevention (CDC). (See "Patient education: Vaccines for adults (Beyond the Basics)".)

The measles, mumps, rubella combined vaccine (MMR) and the chickenpox (varicella) vaccine are particularly important for anyone who could get pregnant and is not already immune to these infections. These vaccines protect from infections that can harm the developing fetus or the pregnancy; however, these are live virus vaccines, and cannot be given during pregnancy or during the month before getting pregnant. People born in the United States who received their routine childhood-recommended vaccines on schedule should already be protected. (See "Patient education: Vaccines for infants and children age 0 to 6 years (Beyond the Basics)".)

Measles, mumps, rubella (MMR) — It is best to confirm that you are immune to these infections before getting pregnant. Immunity is important to protect your developing fetus and this vaccine cannot be given during pregnancy. Your health care provider can determine if you are immune by reviewing your immunization record or with a blood test to assess whether you have an antibody to the vaccine components. If you are not immune, you should receive the MMR vaccine, at least one month before trying to get pregnant. Contracting measles, mumps, or rubella (German measles) in early pregnancy can lead to a miscarriage. Rubella infection in early pregnancy can also cause problems in a developing fetus, and may cause deafness and problems with the fetus or newborn baby's eyes, heart, and/or brain. Measles in adults may be more severe during pregnancy.

If you are pregnant, it is safe for people around you, including your household members, such as your children, to receive the MMR vaccine.

If you are not immune to measles or not certain if you are immune, and learn you were exposed to someone with suspected or confirmed measles, mumps, or rubella while pregnant, contact your health care provider as soon as possible. There is treatment that can help reduce your risk from the exposure.

Varicella (chickenpox) — As with MMR, it is best to confirm that you are immune to the chickenpox (varicella) virus before getting pregnant. If you have never had chickenpox or the full varicella vaccine series, your health care provider can determine if you are immune by doing a blood test. If you are not immune, you should receive the varicella vaccine and then wait at least one month before trying to get pregnant. Getting chickenpox during pregnancy, especially in early pregnancy, increases the risk of problems in the developing fetus. Chickenpox anytime in pregnancy can cause more severe illness and serious complications for pregnant people, such as pneumonia.

It is possible to get chickenpox from exposure to a person with either chickenpox or shingles, also known as zoster. If you are not immune to varicella and are exposed to someone with chickenpox or shingles while pregnant, contact your health care provider as soon as possible. They can assess your risk and decide if a treatment called varicella-zoster immune globulin (VariZIG), which can be given after an exposure, is appropriate for you.

Shingles vaccine — There are two available vaccines to prevent shingles (zoster). One is a live vaccine, meaning it contains the live virus; the other is a nonlive "recombinant" vaccine. The live shingles vaccine should not be given to pregnant people and it is no longer available in many countries, including the United States.

There is no safety information available for the recombinant vaccine, which is newer. The recombinant vaccine for shingles is only recommended for those under age 50 if they have certain medical conditions that puts them at high risk of shingles. There are no recommendations yet as to whether pregnant people at risk should receive this vaccine. Most pregnant people who have indications for vaccination can receive the recombinant zoster vaccine when they are no longer pregnant.

Human papillomavirus — The human papillomavirus (HPV) vaccine is recommended for all people 9 to 26 years of age who are not pregnant and for some nonpregnant people 27 to 45 years of age who could be exposed to HPV and were not previously vaccinated. The HPV vaccine is not recommended during pregnancy, although evidence suggests it is safe if given inadvertently during pregnancy (eg, before knowledge of pregnancy). Most pregnant people who need to receive or complete this vaccine series can receive the HPV vaccine when they are no longer pregnant.

VACCINES RECOMMENDED FOR ALL PEOPLE DURING EVERY PREGNANCY

Influenza (flu) — Pregnant people and young infants are at an especially high risk of developing complications of influenza. The injectable (intramuscular) seasonal influenza vaccine (the injection "flu shot") is recommended for all people who are or will be pregnant during the influenza season (Northern hemisphere: October to March; Southern hemisphere: April to September). Getting the flu shot during pregnancy has no known harmful effects for the fetus. In addition to protecting pregnant people, it helps protect babies from influenza in the first six months after birth, before they are old enough to receive the flu vaccine themselves. The nasal spray form of the influenza vaccine should be avoided during pregnancy because it is a live virus vaccine. (See "Patient education: Influenza prevention (Beyond the Basics)".)

Tetanus, diphtheria, and pertussis (Tdap) — The tetanus, diphtheria, acellular pertussis (whooping cough) or "Tdap" vaccine is recommended for all pregnant people during each pregnancy, even if they have received it before. It should be given between 27 and 36 weeks of pregnancy. Newborns are at a particularly high risk for severe complications of whooping cough (pertussis), and this vaccine helps protect them from infection and complications. It is also recommended that anyone who will be around the newborn baby, such as family members and caregivers (for example babysitters, including teens) are up to date on all their recommended whooping cough vaccines. If their shot is not up to date, they should get vaccinated in order to protect the baby from contracting the disease

Respiratory syncytial virus (RSV) — In adults, RSV causes an infection that is similar to the common cold or the flu. In babies, RSV can be serious or even deadly. (See "Patient education: Bronchiolitis and RSV in infants and children (Beyond the Basics)".)

There are two ways to prevent RSV in newborns. One way is for the pregnant person to get an RSV vaccine between 32 and 36 weeks of pregnancy (for the Northern hemisphere: September through January; for the Southern hemisphere: April through September). The other way is to give the baby a shot after birth. Both are safe and work well to protect your baby from RSV. If you have already received the RSV vaccine during a previous pregnancy, you do not need to repeat the vaccine during this or future pregnancies. If you do not receive a vaccine during pregnancy and the child is born during RSV season, then the child can receive a shot after birth to help prevent RSV infection. Your health care provider can talk to you about your options and which is best for your situation.

VACCINES RECOMMENDED FOR SELECTED PREGNANT PEOPLE — 

Pregnant people who are at high risk of certain infections due to travel or other circumstance should consider additional vaccines.

Hepatitis A — Hepatitis A is a virus that can cause pregnancy complications, such as premature contractions or problems with the placenta. The vaccine carries no known risks to a developing fetus.

The hepatitis A vaccine is recommended for pregnant people who are at risk for contracting hepatitis A. Risk for hepatitis A can include travel, health related behaviors, medical conditions, or an exposure during an outbreak. If you are not immune and learn you may have been exposed to hepatitis A, you should contact your clinician to see if there are treatments or vaccines you should receive to help prevent infection. (See "Patient education: Hepatitis A (Beyond the Basics)".)

Hepatitis B — Hepatitis B is a serious infection that may cause chronic (lifelong) inflammation of the liver and can be passed from a pregnant person to their fetus. There are several available forms of the hepatitis B vaccine. In the United States, a series of three hepatitis B vaccines is now routinely given during childhood, although many adults were not vaccinated as children. The vaccine carries no known risks to the developing fetus.

The hepatitis B vaccine is recommended for pregnant people who are at risk for acquiring hepatitis B during pregnancy (eg, are living with someone infected with hepatitis B) and for people who started the vaccine series before getting pregnant. (See "Patient education: Hepatitis B (Beyond the Basics)".)

Poliomyelitis — Poliomyelitis (polio) is caused by a virus that can lead to paralysis. Polio has been eliminated from many countries, but some areas of the world are still affected by large polio outbreaks and rarely illness is seen in areas without circulating disease. Pregnant people should avoid travel to areas where polio is present, when possible. (See "Patient education: General travel advice (Beyond the Basics)".)

A vaccine is available to prevent polio. However, polio vaccination is not usually recommended during pregnancy due to a lack of information about the vaccine's safety. If you cannot avoid exposure or travel to an area where polio is prevalent, consult with a travel medicine expert or your clinician to determine whether you should get the inactivated polio vaccine (IPV).

Pneumococcus — Pneumococci are bacteria that are a leading cause of bacterial pneumonia and other infections, such as otitis media (middle ear infection) and meningitis. People at high risk for pneumococcal infections should receive the pneumococcal vaccines.

Ideally, the vaccine(s) should be given before pregnancy. However, the pneumococcal vaccines appear to be safe when given in the second and third trimesters (there is not enough information about the safety of the vaccines during the first trimester). (See "Patient education: Pneumonia prevention in adults (Beyond the Basics)".)

Yellow fever — Yellow fever is a viral disease spread by certain types of mosquitoes. It is associated with liver and kidney damage and bleeding and can lead to death. Outbreaks of this disease may occur in certain tropical regions of South America and sub-Saharan Africa. Also, documentation of a yellow fever vaccine is sometimes required to enter certain countries. If possible, travel to areas with active yellow fever transmission should be avoided during pregnancy.

If such travel is not avoidable and the risk of yellow fever is determined to be high, immunization with a live virus vaccine may be considered during pregnancy. You should consult an infectious disease or travel medicine specialist to discuss your specific situation and whether vaccination is appropriate.

Other vaccines — There are many other available vaccines to protect from other infections, including cholera, meningococcus, mpox, plague, rabies, Japanese encephalitis, typhoid, smallpox, and Haemophilus influenzae B. A health care provider can determine your risk of exposure to these illnesses and the need for vaccination during pregnancy.

COVID-19 VACCINE — 

Coronavirus disease 2019 (COVID-19) is an infection caused by a virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It can cause a fever, cough, and trouble breathing, along with other symptoms. Some people get severely ill from COVID-19. Pregnant people are more likely to develop severe illness due to COVID-19 compared with nonpregnant people.

Experts recommend that pregnant people get vaccinated to reduce the likelihood of becoming infected as well as reduce severity of illness. The COVID-19 vaccines do not increase the risk of miscarriage (pregnancy loss) or harm a developing baby.

In addition to getting vaccinated, you can further protect yourself by avoiding people who are sick, washing your hands frequently, and wearing a face covering in crowded public places.

WHERE TO GET MORE INFORMATION — 

Your health care provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for health care professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient education: Vaccines and pregnancy (The Basics)
Patient education: Avoiding infections in pregnancy (The Basics)
Patient education: What you should know about vaccines (The Basics)
Patient education: Vaccines for adults (The Basics)
Patient education: How to plan and prepare for a healthy pregnancy (The Basics)
Patient education: Group B strep and pregnancy (The Basics)
Patient education: Rubella (The Basics)
Patient education: COVID-19 vaccines (The Basics)
Patient education: COVID-19 and pregnancy (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient education: Avoiding infections in pregnancy (Beyond the Basics)
Patient education: Vaccines for adults (Beyond the Basics)
Patient education: Vaccines for infants and children age 0 to 6 years (Beyond the Basics)
Patient education: Influenza prevention (Beyond the Basics)
Patient education: Hepatitis A (Beyond the Basics)
Patient education: Hepatitis B (Beyond the Basics)
Patient education: General travel advice (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Standard immunizations for nonpregnant adults
Hepatitis B virus immunization in adults
Immunizations during pregnancy
Rubella in pregnancy
Seasonal influenza vaccination in adults
Varicella-zoster virus infection in pregnancy
Poliovirus vaccination

The following organizations also provide reliable health information.

●National Library of Medicine

     (www.nlm.nih.gov/medlineplus/infectionsandpregnancy.html)

●Centers for Disease Control and Prevention (CDC)

●Infectious Diseases Society of America

     (www.idsociety.org)