Pregnancy and Vaccination - Current Research 2021

Women who are pregnant, breastfeeding or planning a pregnancy may have some questions about the safety of Covid-19 vaccines. In pregnancy, physiological changes occur that may increase the risk of Covid-19 complications, particularly for women with comorbidities. With low rates of infection in the community in Australia many women may prefer to delay vaccination. The recent outbreaks in NSW and Victoria are prompting many to consider seeking a vaccination earlier. The decision to be vaccinated or not is a very personal one; current research and global experiences can help you make an informed choice. 

What do the experts say?

The Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) and the Australian Technical Advisory Group on Immunisation (ATAGI) recently released advice that pregnant women are routinely offered the Pfizer vaccine at any stage of pregnancy. This is due to the increased risk of hospital admission, ventilation and severe illness if a woman were to contract coronavirus whilst pregnant. Pregnant women have now been added to Phase 1B of the national vaccination rollout, meaning any pregnant woman who wishes to can now access the Pfizer vaccine. 

What are the Risks to My Baby and I if I get Coronavirus?

From January to October in 2020, 1.3 million cases of coronavirus in women of reproductive age were reported to the USA Center for Disease Control (CDC). Of these, 23,434 were pregnant. Researchers adjusted the data for age, ethnicity and underlying medical conditions, finding that pregnant women were significantly more likely to be hospitalised, receive ventilation and die from Covid-19 when compared with non-pregnant women.

An ongoing meta-analysis of 192 separate studies and case reports confirmed the risks of coronavirus to pregnant women. Amongst pregnant women with a diagnosis of Covid-19, “increased maternal age, high body mass index, non-white ethnicity, any pre-existing maternal comorbidity including chronic hypertension and diabetes, and pre-eclampsia” were associated with more serious outcomes including ventilation and death. 

There is also an increased risk of pre-term birth and admission to neonatal intensive care (NICU) for babies whose mothers have Covid-19.

One study compared birth outcomes at a London hospital before and during the pandemic. There was a significant increase in stillbirths during the pandemic period, however the study could not conclude that the increase was due to coronavirus infection alone. Other potential contributing factors included reduced face-to-face antenatal visits and screening appointments, or a reluctance of women to go to hospital. 

Can I get Covid-19 from the Vaccine? 

Pfizer is a messenger RNA (mRNA) vaccine that does not contain live virus, so it cannot transmit the COVID-19 virus. Vaccines using this technology have been used extensively all over the world, including in pregnant women. This global surveillance has “not identified any significant safety concerns with mRNA COVID-19 vaccines given at any stage of pregnancy”. There is also evidence that antibodies, acquired by vaccination or previous infection, are present in cord blood and breastmilk, and this offers some protection to the baby. 

What is the current research?

Pregnant women are not included in initial clinical trials for new medicines and vaccines, however no adverse outcomes were found amongst the small number of women (57) who accidentally became pregnant during initial trials. In 2021, many countries including the United States and United Kingdom have vaccinated pregnant women. No significant adverse outcomes have been reported and monitoring is continuing . Scientific trials that include pregnant women who receive the vaccine are underway. It is anticipated that these will demonstrate the safety of the vaccine in pregnancy, as well as a number of benefits to both the mother and baby, given the risks of covid-19 infection.

What if I am Breastfeeding?

A small study in Israel analysed breastmilk samples of women who had received an mRNA vaccine. The breastmilk samples were found to contain high levels of antibodies, offering the baby immune protection against Covid-19. Arm pain following injection was a common side effect for the mother, however none of the mothers or babies experienced significant adverse reactions.

What If I am Planning to Get Pregnant Soon? 

Women planning a pregnancy are understandably concerned that receiving the Covid-19 vaccine may impact on their future fertility. Though mRNA vaccines are relatively new, they have been in human trials since 2006 and no concerns around fertility have been noted. There is also no theoretical mechanism through which the vaccine could impact on any fertility.

The choice to get vaccinated is personal and needs to take into account your individual circumstances, including underlying health problems and the risk of exposure to coronavirus. Having the most up-to-date information to hand is important for making an informed decision. Current research, as well as information collated from around the world demonstrate the safety of vaccination for pregnant and breastfeeding women, should they wish to receive one.