What an obstetrician says about the COVID-19 vaccine and pregnancy

Health-care professionals in Canada and beyond have advised pregnant women to get vaccinated against COVID-19.

But some expectants mothers are nevertheless hesitant to receive the shot, citing worries about hurting their unborn child.

Dr. Heather Scott, head of obstetrics at theIWK Health Centre in Halifax, spoke with CBC News to address some of those concerns.

The interview has been edited and condensed for length and clarity.

There are a number of women who are hesitant to get the COVID-19 vaccine while pregnant. Should pregnant women get the vaccine?

We understand that there is hesitancy about it. But the recommendation is that all pregnant women, regardless of how far along they are in pregnancy, should receive the COVID-19 vaccine.

What is behind that advice?

We do havea wealth of information about outcomes in pregnancy when a woman acquires the infection. What we knowis that pregnant women who become infected with COVID-19 have a higher risk of hospitalization. It's probably about four to five times higher than those individuals who are not pregnant in the same age group. And they also have a higher chance of admission to the intensive care unit.

The other thing that we know from accumulating information from around the world is that there is an increased risk of what we would call adverse perinatal outcomes [for pregnant womeninfected with COVID-19]. That means risk to the fetus as well. There's a risk of preterm birth, which has been quite clearly documented, and also an increased risk of stillbirth, which has been associated with COVID-19 when a baby is delivered prematurely. That means things like admission to the intensive care unit for the baby and respiratory problems.

How do we know the vaccine won't harm the fetus?

There is now a data set globally that includes over 80,000 individuals who have received the vaccine in pregnancy. That number is not small. When that data is examined, there are no red flags to suggest that there is an adverse outcome related to receiving the vaccine. There was just recently a report published in the New England Journal of Medicine which stated that there was no increased risk of first trimester loss or miscarriage associated with it.

What we also know is that although the COVID-19 vaccine itself is new, the mRNA vaccine is not new, and we do have information that dates back quite a ways that suggests that it's a safe vaccine in pregnancy. It is not what we call a live vaccine, so there is no risk of getting the infection, and there is nothing in the vaccine which has ever been shown to be harmful to a fetus.

If there's no long-term data, how can we be sureit's safe during pregnancy?

We have to try to reassure women that this type of vaccine is not new and that it has been demonstrated in the past to be safe. I think we have to ask women and pregnant individuals to balance risks and benefits. We now know that there are over 8,500 pregnant women [in Canada] who have acquired the infection during pregnancy, and that's where we're collecting the information about the adverse outcomes. So while we understand hesitancy about receiving something new that many would perceive as being relatively understudied, we are trying to reassure those same people that we do, in fact, have quite a bit of information about the safety of the vaccine, and we have quite a bit of information about the effectsthe infection has on pregnant individuals.

Pregnant womenare told to avoid so many things, everything from raw fish to over-the-counter medications. How is the vaccine different?

We have clearly documented reasons for not giving such medications in terms of the effects on the fetus. Most of those recommendations are because we know that there can be negative consequences. This is not the case for the vaccine. There is no evidence at all that by administering the vaccine, there is a negative impact on the developing fetus. As I said, we now have information from over 80,000 pregnant individuals who have received the vaccine and there does not appear to be any negative impact. That's very different from medications that are well studied and that have been demonstrated to show an adverse effect on pregnant people.

Does the vaccine affect fertility?

Itunequivocally does not affect fertility. It's an unfortunate myth. I think that it's associated with vaccines, that they do affect fertility and it is out there in social media. We've done our best to dispel that myth because I really feel that it can be harmful. There are many people who would like to conceive who are potentially holding off on the vaccine because of very inaccurate information about it affecting fertility. It does not.

There has been some information out there about it altering the menstrual cycle. If it does change the menstrual cycle, it wouldonly be for one or two cycles. And again, it's not associated with a change in fertility.

How can you say that with certainty? How doesitaffect menstrual cycles?

There's no scientific reasonfor it to affect fertility. It doesn't. The way the vaccine works and the evidence that we have, there isn't any logical reason why it would affect fertility. Studies using mNRAvaccines and other vaccines have never actually demonstrated a change in fertility.

We're just getting information about why,if it is even true,it affects the menstrual cycle. The difficulty with the menstrual cycle is that it's subject to all kinds of changes based on stress and eating habits and exercise and that kind of thing. So, I think we're just learning about what that may do. What little information we have about ithas suggestedthat it might affect the cycle for one to two months, if that. Butas I said, it could be impacted by any number of things that change the menstrual cycle. But the cycle then does go back to being completely normal.

What is the advice for women who arebreastfeeding? Should they get the vaccine?

The adviceis to get the vaccine even if you are breastfeeding, based on it being potentially a positive thing that antibodies from the mother will potentially passintobreast milk. Ifshe receives the vaccine during pregnancy, which of course stimulates the production of antibodies, those antibodies can cross the placenta and protect the newborn. The same would be the case for antibodies getting into breast milk. Again, there is nothing in the vaccine that would have a negative impact on a baby, should there be anything in the breast milk. So rather than it being a negative thing, it would be a positive thing, with the transmission of antibodies into breast milk.

If an individual does decide to be vaccinated during pregnancy, does it matter when they're vaccinated?

Initially, we were not certain whether it was safe to give during the first trimester.We were worried about people developing a high fever, that kind of thing.I think thatis why, in part, there's been some hesitancy,because the guidance and information has changed over time as we've acquired more information.But we have realized that there doesn't appear to be risks in the first trimester.

If you received the first shot prior to pregnancy and thenconceived, you could receive a second shot. You can receive both shots during the pregnancy or receivethe first shot late in the pregnancy andreceive the second shot while you're breastfeeding.Any of these are safe options with the safest thing being that you are fully immunized.

What is your message to pregnant women in Nova Scotia and beyond?

I do want pregnant women in this province to feel supported in their decisions, regardless of what that decision is. But I also really want those same individuals to have the most accurate information and to feel that they can make an informed decision. I do want those people to recognize that there is actually quite a bit of information from around the world that supports the safety of the vaccine and the strong recommendation that pregnant individuals be vaccinated.