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COVID-19 vaccines and pregnancy, fertility and breastfeeding

Pregnant women are now categorised as Phase 1b in the National Vaccine Rollout and are therefore eligible for the Pfizer COVID-19 vaccine (Comirnaty) or Moderna (Spikevax).

Pregnant women should be routinely recommended Pfizer (Cominarty) or Moderna (Spikevax) at any stage of pregnancy. There is good real-world evidence supporting the safety of vaccination throughout pregnancy and prior to conception. Vaccination reduces the risk of adverse perinatal outcomes associated with COVID-19.

This position is supported by the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) as per this statement. Queensland Health’s peak clinical bodies also strongly encourage vaccination as per this Joint statement from the Queensland Clinical Senate and Statewide Clinical Networks (PDF 212 kB).

Why vaccination is important for pregnant women

Whilst pregnant women are not at a greater risk of contracting COVID-19 compared to the general population, vaccinating pregnant women against COVID-19 is strongly recommended by Australia’s peak clinical bodies because:

  • Pregnant women who contract COVID-19 Delta variant have a higher risk of severe illness compared to non-pregnant women of the same age, including:
    • 2.1 times more likely to require ICU admission/care
    • 2.6 times more likely to require support from a mechanical ventilator
    • 2 times more likely to require Extra-Corporeal Membrane Oxygenation (ECMO)
    • 2.9 times more likely to die.
  • There is a higher risk of adverse outcomes as a result of contracting COVID-19, and infants born to women who contract COVID-19 during pregnancy have a higher risk of adverse outcomes, including:
    • 1.5 rimes more likely to have a pre-term birth
    • 4.9 times more likely to require admission to a neonatal intensive care unit.

The Delta variant is currently the most dominant strain in Australia and globally. Delta is more infective (it infects more people more easily) and causes more severe infections than the original or other strains. Internationally and in Australia there has been a marked increase in the number of pregnant women with severe COVID due to Delta variant. Please refer to approximately 00:08:33 in the pregnancy and COVID-19 vaccines information session recording for more information on this.

The vaccines perform well against the Delta variant with two doses of Pfizer or Moderna  providing 80-95 per cent protection and two doses of COVID-19 Vaccine AstraZeneca providing 65-70 per cent protection against any symptomatic disease. This is discussed at approximately 00:07:02 in the pregnancy and COVID-19 vaccines information session recording. The vaccines perform even better at preventing severe disease and ICU admission with all three vaccines demonstrating 90-99 per cent effectiveness. Pregnant women who have already received a first dose of Astra Zeneca vaccine can receive either of the mRNA vaccines or the AstraZeneca vaccine for their second dose.

Whilst cases of Delta currently are low in Queensland, at some point in the near future our numbers will increase, and community transmission will grow. We need to continue to protect individuals against severe COVID-19, and vaccination remains the best method of protection.

Individuals are not fully protected until at least two weeks after their second dose. Therefore, individuals who vaccinate now will be fully protected in six weeks depending on the vaccine. This is particularly important as Delta outbreaks in New South Wales and Victoria continue, placing Queensland at risk of COVID cases.

Relying on herd immunity will not provide protection from COVID.

About the vaccines

As discussed at 00:15:48 in the vaccines and pregnancy information session recording, mRNA vaccine technology is not new.

Scientists around the world were already working on vaccines when the SARS-CoV-2 pandemic started. The magnitude of the pandemic led to unprecedented funding and global collaboration, enabling some processes to run in parallel. This has not compromised rigour or assessment processes. Safety, immunogenicity and efficacy outcomes are strictly assessed and safety monitoring continues even after approval.

On top of intense international scrutiny, all vaccines in Australia have been reviewed and approved by the Therapeutic Goods Administration (TGA) as will any subsequent vaccine candidates. This includes careful analysis of clinical trial data, ingredients, chemistry, manufacturing and other factors. This process is amongst one of the most thorough in the world. All new agents and medicines in Australia have “provisional approval” for two years. Provisional approval by the TGA does not mean the vaccine is not approved or is a trial product.

The Pfizer Comirnaty and Moderna Spikevax vaccines have a B1 rating in pregnancy in Australia which is the highest classification possible for a new therapy.

It is important to note that the TGA, the Australian Technical Advisory Group on Immunisation (ATAGI) consider and review a range of studies, data and evidence before making a recommendation.

The vaccines are not ‘live’ vaccines so they cannot cause COVID-19 infection in you or your baby. Live vaccines have previously been shown to be safe in pregnancy, for example whooping cough and influenza (the vaccine for which changes each year). The COVID vaccines also do not contain any ingredients that would be considered harmful to a pregnant woman or a developing baby.

mRNA vaccines do not alter your DNA or genetic code and are not considered biologically or scientifically plausible to cause genetic harm. The mRNA vaccines (Pfizer and Moderna) are quickly broken down once they have been injected – within a few days of vaccination there will be no vaccine mRNA left.

Side effects associated with the COVID-19 vaccines are generally mild and will only last one to two days. Discomfort can be treated with paracetamol, which is safe to have during pregnancy, whilst undergoing fertility treatments and whilst breastfeeding.

Contraindications for COVID vaccination are outlined in the Australian Technical Advisory Group on Immunisation (ATAGI) Clinical Guidance document.

Vaccination timing and scheduling

COVID vaccination is recommended at any time during pregnancy to protect the pregnant woman as soon as possible.

Influenza and pertussis (whooping cough) vaccinations continue to be recommended during pregnancy. These vaccines can be administered in addition to the Pfizer mRNA vaccine (Cominarty) or Moderna (Spikevax) vaccines by following the recommended dosing schedule. Queensland recommends at least a seven (7) day interval between a dose of a COVID-19 vaccine and other vaccines, including seasonal flu vaccine and pertussis.

Vaccination before the third trimester may support perinatal outcomes, as normal changes to the mother’s respiratory system commonly increase severity of viral respiratory illness during the third trimester.

Considerations for high risk pregnancies

General practitioners, midwives, obstetricians and other health professionals involved in the care of a pregnant woman may wish to refer high-risk pregnancies to the Statewide Queensland Adult Specialist Immunisation Service (QASIS) at the Royal Brisbane and Women’s Hospital for advice on vaccination. Referrals can be made via the Metro North Health Central Patient Intake Unit.

Fertility and IVF

The Australian Technical Advisory Group on Immunisation (ATAGI) and RANZCOG advise that women who are trying to become pregnant do not need to delay vaccination or avoid becoming pregnant after vaccination.

The Australian and New Zealand Society of Reproductive Endocrinology and Infertility advises:

  • There is no evidence the COVID vaccines will affect your fertility or the outcomes of your treatment cycle or your reproductive health.
  • There is no reason to delay fertility treatment. If you wish to delay treatment until your second dose of the vaccine for COVID-19, a few months delay is unlikely to reduce your chance of pregnancy unless you have a low ovarian reserve or are over 37 years of age.

Taking into account that some people may experience minor side effects in the few days after vaccination, the British Fertility Society recommends considering the timing of your vaccine. For example, it may be sensible to separate the date of vaccination by a few days from some treatment procedures (for example egg collection and embryo transfer in IVF) so that any symptoms, such as fever, might be attributed correctly to the vaccine or the treatment procedure.

The COVID-19 vaccines are safe for those undergoing immune suppressing treatments as they do not contain any ‘live’ virus. However, the level of antibodies produced by the body may be reduced, lowering your level of protection. As outlined on our FAQ page, vaccination for immunosuppressed and immunocompromised is strongly encouraged.

Are the COVID-19 vaccines safe for lactating women?

If you are breastfeeding, you can receive the Pfizer or Moderna COVID-19 vaccine at any time. You do not need to stop breastfeeding before or after vaccination. COVID-19 vaccination may also provide indirect protection to babies by transferring antibodies through the placenta (for pregnant women) or through breastmilk (for breastfeeding women).

In the UK, a small number of women have reported decreases in their milk supply following vaccination with a COVID-19 vaccine. While a number of factors can affect milk supply and infant behaviour, including general maternal health, amount of sleep, and anxiety, it may be helpful for breastfeeding women to know how to maintain their breast milk supply, particularly if they are feeling unwell.

Queensland Health has a range of resources to support breastfeeding:

Developing babies and longer-term effects

Medium and long-term (more than one year) safety data is not yet available, as the vaccines are relatively new. However, health organisations and professional colleges are confident in the science of mRNA vaccinations and the chance of any adverse outcome, in any trimester, on balance, is extremely low.

As pregnant women are not included in clinical trials, there is no data directly comparing how well the vaccine works in pregnant women with non-pregnant women. There is good real-world evidence supporting the safety of vaccination for the pregnant woman with substantial data from across the globe about vaccine safety during pregnancy:

  • In the United States of America, analysis of the CDC V-Safe COVID-19 pregnancy registry including 2,456 people concluded risk of spontaneous pregnancy loss at less than 20 weeks, is not increased in people who are vaccinated.
  • In the US, 148,000 pregnant women have been vaccinated with mRNA vaccines with no increase in incidents of adverse pregnancy outcomes or increased congenital abnormalities.
  • Israeli data showed vaccines were strongly protective against any COVID-19 infection and there were no safety concerns.
  • In the UK approximately 66,000 pregnant women were vaccinated with mRNA vaccines with no evidence of an increase in miscarriages or adverse outcomes.
  • Research from across six studies in four countries, involving more than 40,000 pregnant women, demonstrates that vaccination does not increase the risk of miscarriage, preterm birth, stillbirth, nor does it increase the risk of a small-for-gestational age baby, or of congenital abnormalities.

This is discussed at approximately 00:22:00 in the pregnancy and COVID-19 vaccines information session.

Studies have shown that protective antibodies from vaccination cross the placenta and may help protect the baby from COVID-19. The mRNA vaccines (Pfizer and Moderna) are quickly broken down once they have been injected – within a few days of vaccination there will be no vaccine mRNA left.

Changes to menstrual cycles or bleeding

The Therapeutic Goods Administration (TGA) has carried out an investigation of menstrual problems and unexpected vaginal bleeding suspected to be related to COVID-19 vaccination. The investigation did not find evidence for a link between vaccination and menstrual problems, but the TGA continues to monitor this issue as part of their routine vaccine surveillance activities.

An expert review panel in the UK has investigated reports of suspected side effects, menstrual disorders and unexpected vaginal bleeding following vaccination against COVID-19. The rigorous evaluation completed to date does not support a link between changes to menstrual periods and related symptoms and COVID-19 vaccines. The changes are also thought to be transient in nature with no evidence to suggest it affects fertility.

Anyone experiencing changes to their periods that are unusual for them, persist over time, or have occurred after menopause should contact their doctor.

Myocarditis and pericarditis

In Australia, myocarditis and pericarditis are very rare effects on the heart that typically occur within 10 days of vaccination with the mRNA vaccines Comirnaty (Pfizer) and Spikevax (Moderna). Cases are usually transient and resolve following treatment and rest.

International data indicates that cases are more frequently reported in teenage boys after the second dose. To 19 September, the Therapeutic Goods Administration (TGA) has received eight reports of suspected myocarditis in adolescents aged 15-17 years – 7 boys and one girl. Four of the cases occurred after the second dose. Myocarditis and pericarditis attributed to previous mRNA vaccine are contraindications to COVID vaccination.

Taking care of your mental health and wellbeing

COVID-19 may affect your mental wellbeing and place added stress on relationships and at work. During pregnancy, most women experience a range of emotions. It’s normal to feel some worry during pregnancy and when having a baby. If you feel worrying thoughts are becoming a regular part of life, it can help to talk about any concerns with your doctor, midwife, partner or a close friend. It is important to take care of yourself and share any concerns.

Advice for engaging with pregnant patients

The Australian College of Midwives (ACM) has developed tools to assist midwives and other health professionals when they engage with women about the COVID-19 vaccines:

An e-Learning package for midwives has also been developed along with significant education and evidence statements available on the ACM website.

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Last updated: 8 October 2021