Flu jabs and miscarriage

You may have read reports recently of a recent US study that appears to link yearly vaccines, like the flu vaccine, to miscarriage. Tommy’s urges you not to worry and explains more about how this study was made and what it means.

Tommy's news, 19/09/2017

Recently a study in the US has researched the link between flu vaccinations and miscarriage risk. They looked at women who had been given a swine flu vaccine between 2010 and 2012 and whether this increased their risk of miscarriage.

The UK media has picked up and shared this report. If you are anxious about having the flu vaccination because you're worried about how it might affect your pregnancy, we want to reassure you that this study does not confirm or prove a link between vaccinations and miscarriage. The evidence still suggests that it is safer for you and your baby to have the flu vaccine.

Tommy’s midwife Anna Nella explains,

"Pregnant women are at increased risk of becoming very ill from complications if they get flu. A mum who contracts flu may give birth prematurely or her baby could be stillborn. The flu vaccine can also extend protection from flu to the newborn. We would urge all mums to protect themselves and their babies by having their flu vaccine now to be prepared for when the virus is spreading over the winter months. The flu vaccine is available free from September to January to all pregnant women. It is safe to have it at any time of pregnancy. Flu vaccines save mums and babies lives."

Behind the headlines:

  • This result came from an analysis after the investigation took place, and wasn’t what the study was initially looking into. This means that the right controls for the study weren’t in place.
  • The women studied were only matched for the time of their last period, the hospital they were in and their age. The study didn’t take into account other known factors that can cause miscarriage like diabetes, BMI, previous miscarriage history and smoking when they were testing these women. This means that there was a bias amongst the women they tested.
  • The study looked at 485 pairs of women – to have a fair test, you need at least 500 pairs of women.
  • On top of this, the conclusion that the vaccine is linked to miscarriage only came from a sub-group of these 485 paired women – so that makes the ‘pool’ of women they were testing from even smaller.
  • The vaccine was linked to miscarriage in one season, but not in the season the year after. To see if there really is a link, you would also need to conduct the study over a much longer period of time.

Whilst it’s important that more studies are being conducted into the causes of pregnancy loss, it can be very worrying for women and their partners who are expecting a baby, and may have suffered miscarriages previously, to read about unverified reports in the media. Remember that if you are ever worried about something you read or hear, you can get in touch with us at Tommy’s to talk it through. We have world renowned experts at our four centres in the UK who can check and verify reports from around the world, and a team of midwives who can talk you through the best options for you and your health.

If you are pregnant and feel like you are coming down with the flu, go to see your GP as soon as you can so you can get the support that you need.

How to have a safer pregnancy

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