Emma Smith* has always gotten all the vaccines her doctor recommended during her pregnancy.
“I’m someone who believes in science and trusts the science, and also my doctors, so the conversation wasn’t around should I or shouldn’t I, but when should I get them,” says the Montreal mom, who’s expecting her third baby this summer.
Even if you’re someone like Smith, who believes vaccines are an important part of your healthcare arsenal, it can be confusing to know what’s safe during pregnancy and you might be worried about any adverse effects of immunizations on your baby.
“The vaccines that are recommended for every pregnant woman in Canada are the influenza (flu) vaccine and the pertussis (whooping cough) vaccine,” says Vanessa Poliquin, an OB/GYN and reproductive infections disease specialist at Winnipeg Health Sciences Centre. “These vaccines protect both the mother from illness and also the infant for the first several months of life,” she says.
Here’s how it works: after mom receives a vaccine, her body produces antibodies that can be passed across the placenta, giving baby protection that will last for several months after birth. This will cover them until they receive their own shots—recommended at two months for whooping cough, and six months of age for the flu.
Flu shot during pregnancy
Canada’s National Advisory Committee on Immunization recommends that, no matter what stage of pregnancy they’re at, moms-to-be get the inactivated influenza vaccine via injection during flu season (which is generally between October and April). That’s because pregnant women are at increased risk for flu-related complications that can require hospitalization. Newborns are also at risk of flu-related complications.
Whooping cough (Tdap) vaccine during pregnancy
Most of us support mandatory vaccinations—but is there a downside?The TdaP vaccine for whooping cough (pertussis), tetanus and diphtheria is a new recommendation, added in 2018, and it’s suggested pregnant women should receive it between 27 and 32 weeks gestation, even if you’ve received the shot before. That’s so you can pass some of the protective antibodies to baby before they are born, providing potentially life-saving immunity. Pertussis can cause pneumonia, brain damage and is considered deadly for newborns.
Measles (MMR) vaccine during pregnancy
Measles is the other vaccine-preventable disease on the minds of moms across the country. “With measles outbreaks popping up around Canada, many new mothers are facing real concerns about their newborn infants being exposed,” says Poliquin. But, babies normally aren’t vaccinated until they’re about 12 months. In this case, having antibodies already on board is key. Unfortunately there’s a catch: the MMR vaccine (for measles, mumps and rubella) is live, so if you’re already expecting, don’t expect your practitioner to offer you a booster.
“In general, live virus vaccines are not administered during pregnancy because there is a theoretical risk of infection to the fetus,” says Sarah Tranquilli-Doherty, family physician who provides obstetrical care at St. Paul’s Hospital in Vancouver. Other live vaccines like the herpes zoster for shingles and oral typhoid are also contra-indicated during pregnancy.
“My advice is to see your primary care provider if getting pregnant is even a possibility and talk to them about whether you are immune [to measles],” says Poliquin. (You also want to be immune to rubella, since an infection during pregnancy puts baby at risk of serious birth defects and can even cause miscarriage.) There’s a good chance you received one or two doses of the vaccine in childhood (vaccine schedules vary slightly by province, but MMR is typically given to kids sometime after 12 months. A second shot was introduced in the mid-nineties, and many provinces had catch-up campaigns to vaccinate those who only received one shot.) If you got the vaccine, you’re probably still protected. If you’re not sure if you were immunized, your practitioner may suggest a blood test to see if you have sufficient antibodies. If you’re not immune, but already expecting, you’ll have to wait until after baby arrives to get the vaccine – and baby won’t get any protection until their 1-year shots.
“In these circumstances I would encourage the family and friends around a pregnant woman to make sure their vaccines are up-to-date,” says Poliquin.
It’s not a bad idea in general to also think about the immunization status of close family who will be around you and your newborn. “This one’s going to be a summer baby, but my second was born in January, at the height of flu season, so we made sure everyone was up on the flu shots, including our eldest daughter who was in daycare,” says Smith. Her parents also volunteered to receive whooping cough boosters as well as flu shots, just to be safe.
Travel vaccines during pregnancy
If you’re a mom-to-be with wanderlust, you may be wondering about travel vaccines, too. The shot for yellow fever, which is recommended if you’re heading to Argentina or Brazil, for example, is one that’s not considered safe while you’re expecting (which may cause you to reconsider your travel plans). But, hepatitis A and B vaccines, which are frequently recommended for vacationers headed to any developing countries, are both OK to receive during pregnancy. “I encourage pregnant women to speak with their primary care provider or travel medicine specialist to tailor the discussion to their specific travel needs,” says Poliquin. You’ll need to address these at least four to six weeks before you travel, to give the vaccines time to take effect.
Some vaccines, like the Bacillus Calmette-Guerin (BCG) shot for tuberculosis and vaccine for yellow fever, can be passed through breastmilk and as a result are not recommended as long as you are nursing, since they are not considered safe for babies. A small amount of antibody from the flu shot, on the other hand, can be passed through breastmilk to baby’s benefit since it will safely bolster their immunity to influenza. Smith says she’ll get the flu shot this fall too, as she always does, since she knows it’ll give her newborn that extra protection. “We’re just doing everything we can to prevent having a sick baby,” she says.
*name has been changed