COVID vaccines in pregnancy

Unvaccinated pregnant women catching COVID and becoming severely unwell is a significant cause for alarm in hospitals across the UK at the moment. The guidance is that, just as for flu, pregnant women should be vaccinated against COVID as a priority, but many have not taken up the offer and are now accounting for up to a fifth of the most severely ill cases being managed in some intensive care units. Cambridge University obstetrician Catherine Aiken is deeply concerned, and spoke with Chris Smith…

Catherine - We're seeing up to 200 pregnant women a week who are sick enough from COVID to need to be admitted to hospital. And we know that if a pregnant woman is admitted to hospital with COVID, then she's got a one in 10 chance of being sick enough to actually need an ITU bed and a one in five chance of being sick enough to need breathing support. We also know that it's very bad for babies. COVID doubles the risk of stillbirth in mums who need to be hospitalised, and one in five of the women who's admitted to hospital with COVID has a premature baby, which obviously can have lifelong effects for that child.

Chris - And, of course, these are, by and large, young, healthy people on the whole, aren't they? Who would normally have an extremely low risk of running into trouble with coronavirus infection.

Catherine - Absolutely. We are seeing a really striking increase in sickness among young women with no other real health problems, whose main risk is being pregnant, particularly after 28 weeks in the third trimester of pregnancy.

Chris - Do we know why pregnancy intensifies the risk for COVID, but also a raft of other infections? I'm thinking chicken pox is much worse if you catch that when you're pregnant, isn't it? And a number of other infections that seem to intensify. The flu as well, for example.

Catherine - That's really to do with how the body changes in pregnancy overall. And it's certainly, as you say, not unique to COVID. It's to do with the immune system changes, the hormonal changes, and the changes in breathing and heart function that need to occur in order to support a baby and have a healthy pregnancy. They work extremely well when things are going well, but they can actually be counterproductive if a mum gets really ill during a pregnancy.

Chris - And the women that are ending up in a parlous state with COVID, are they vaccinated or are they unvaccinated?

Catherine - So that's really, really striking. What we know between the start of this year and up to the end of September is that 99% of pregnant women who were admitted to hospital with COVID hadn't been fully vaccinated. The rates of hospitalisation among vaccinated, pregnant women are exceptionally low, and the latest report from the UK surveillance system shows that no vaccinated woman has needed to go to ITU for some time.

Chris - And do we know what fraction of pregnant women are vaccinated?

Catherine - That's a really interesting question because data aren't collected that way nationally. However, that's one of the things that is now being worked on at a national scale, to make sure that we will have those numbers in the future.

Chris - It seems something of an oversight that we didn't actually collect that data. Do you think we're, to a certain extent, reaping what we sowed here? Because when all this began, women who were pregnant were told, don't have the vaccine, you have to isolate instead, you have to shield, because we haven't got data on the safety of the vaccine. Now they're being told, go and get the vaccine. So, are they sceptical with good reason?

Catherine - I think it's a really, really difficult thing to work against poor public health messaging that has previously been out there. As you say, the initial JCVI recommendations excluded pregnant and breastfeeding women from having the vaccine. Now that was on the basis that they hadn't been in the trials. And I can understand why they weren't in the trials, because these trials had to be begun very quickly, and adding pregnant or breastfeeding women creates a whole other delay to beginning a trial, because safety in that sense has to be assessed as well. And so they weren't included in the trial, and so they were excluded from the initial recommendations about who should have the vaccine. The trouble was that they weren't excluded on the basis of any plausibility or reason to think that it wouldn't be okay. They were simply excluded because it hadn't been tested that way. The position now is very, very different because we have data from well over a quarter of a million women in various countries who have had the vaccine without any adverse effect on them or their baby at all. However, you're right that that initial messaging has been very, very difficult to roll back. And, unfortunately, many people interpret it to mean that it wasn't safe, and that worry is very hard to shake off.

Chris - So what's happening is people are essentially trading a theoretical risk that something might happen with this vaccine, against a very real risk that if they catch coronavirus, they are at extreme risk of getting extremely unwell?

Catherine - That's right. The data are actually very much in favour of this being a very safe thing to do, whereas coronavirus is a very dangerous thing to risk during pregnancy. And I think it's important to say that there's no rational reason that we have to think that a COVID vaccination could harm babies. It's not a live vaccine, it doesn't contain any virus at all, and we routinely give other non-live vaccines, such as flu and whooping cough in pregnancy. The vaccines don't contain ingredients that are harmful to mums or babies. And we do have evidence from at least a quarter of a million pregnant women that they don't cause in-fetal anomalies or problems.

Chris - Given the government have made this announcement this week, there's obviously a very significant concern, especially as we go into winter and we're going to probably see more instances of this. So, is it a case now that we just encourage, or should encourage, as many women who are not vaccinated and are pregnant, or are about to get pregnant, to go and get vaccinated?

Catherine - Absolutely. We are seeing heart-breaking stories every day of otherwise well women who are extremely ill and they and their babies are at very high risk.