New Year, new vaccines. And praise the universe for that! With the roll out of the vaccines, the dark shadows of the pandemic are beginning to lift. We can see the promised post-COVID-19 sunny uplands on the horizon.
Three vaccines have so far been approved variously in the EU, US and UK. These are from Pfizer-BioNTech, Moderna and Oxford-AstraZeneca. Additional ones available in some countries from companies based in India, Russia and China.
We know the benefits of reducing the symptoms of COVID-19. But what are the risks of these vaccines in terms of pregnancy and preparing for pregnancy?
The EU and UK product information for the Pfizer vaccine notes:
- There is limited experience in pregnant women. Pregnant women were excluded from the clinical trial, but 23 women did become pregnant during it with no harmful effects noted
- Animal studies indicate no harmful effects in pregnancy or post-natal development.
However, the EU and UK authorities advise, “Use in pregnancy should only be considered when the potential benefits outweigh any potential risks for the mother and foetus.”
The EU/UK product information for the Moderna vaccine is identical to the Pfizer vaccine.
- Pregnancy: there is limited experience with use of the Moderna vaccine in pregnant women
- Animal studies do not indicate direct or indirect harmful effects with respect to pregnancy, embryo/foetal development or post-natal development.
As with the Pfizer vaccine, the EU authorities advise that the vaccine should only be considered in pregnant women when the potential benefits outweigh any potential risks for the mother and unborn child.
Available product information for the Oxford-AstraZeneca vaccine is similar to the other vaccines.
● Pregnancy: there is a limited experience with the use of the Oxford-AstraZeneca vaccine in pregnant women
● Animal studies so far do not indicate direct or indirect harmful effects with respect to pregnancy, embryo development, or postnatal development.
However, the authorities note that definitive animal studies have not been completed yet.
They also make the point that the full relevance of animal studies to human risk remains to be established
Fertility: preliminary animal studies do not indicate direct or indirect harmful effects with respect to fertility.
As with the other vaccines the authorities recommend that administration of the vaccine in pregnancy should only be considered when the potential benefits outweigh any potential risks for the mother and unborn baby.
So where does this leave us?
The Pfizer vaccine was reviewed by the World Health Organisation (WHO), which stated that vaccination should only be considered where the benefits outweigh the risks. In making this statement they noted that, “Pregnant women are at higher risk of severe COVID-19 than non-pregnant women and COVID-19 has been associated with an increased risk of pre-term birth.”
This review has led WHO to make two recommendations regarding vaccination and pregnancy:
- High risk of exposure to COVID-19: vaccination should be considered if a pregnant woman has an unavoidable risk of high exposure to COVID-19, for example in a health worker
- Low rIsk of exposure to COVID-19: for women who are not at high risk of exposure to COVID-19, WHO advise avoiding pregnancy for 2 to 3 months post-vaccination.
What about assisted reproduction?
The European Society for Human Reproduction and Embryology (ESHRE) follows the WHO guidance. On the question of whether couples who receive vaccination should postpone treatment ESHRE says, “It is prudent to postpone the start of assisted reproduction treatments such as sperm collection, ovarian stimulation, embryo transfer for at least a few days after the completion of vaccination.” By completion they mean after the second dose.
ESHRE added, “A more cautious approach could be considered i.e., postpone the start of ART treatment for up to 2 months.”
In the US, the American Society for Reproductive Medicine (ASRM) is less cautious with regard to, specifically the Pfizer vaccine. They advise that, ‘Since the Pfizer vaccine is not a live virus, there is no reason to delay pregnancy attempts because of vaccination administration or to defer treatment until the second dose has been administered.”
This all may seem less than definitive but unfortunately that is extent of available information at the moment. However, the good news is that the weighing of the benefits and risks of vaccination versus delaying pregnancy or assisted reproduction therapies is not a process that has to be undertaken without advice.
As the ESHRE statement noted, “This is a matter for close collaboration with a healthcare professional and access to fertility treatment should not depend on an individual’s decision to be vaccinated or not.”