By Dr Michael van der Griend, Obstetrician and Gynaecologist, Head of Obstetrics at North Shore Private Hospital
In Australia, there are currently 2 vaccines approved for use:
- Astra Zeneca – a viral vector vaccine
- Pfizer – A mRNA vaccine
Current advice is for all pregnant women to be offered COVID 19 vaccine with Pfizer being the preferred vaccine as most of the data regarding pregnancy vaccination comes from the USA where Pfizer or Moderna are given and because of the rare complication of vaccine-induced thrombosis with Astra Zeneca, the Astra Zeneca vaccine should be avoided unless a first dose has already been given without any adverse effects.
Safety:
Over 120 000 pregnant women in the USA have received Pfizer or Moderna vaccine to date.
Common side effects included pain at the injection site, fatigue and low-grade fever – but the incidence was similar for non-pregnant women who were vaccinated.
The risk of miscarriage was 12.6% which is similar to the background spontaneous miscarriage rate.
The incidence of congenital anomalies in the vaccinated group was 2.2% which is the same background rate as the general non vaccinated population.
Following COVID vaccination antibodies can be detected in cord blood samples and breast milk – similar to that found with pertussis (whooping cough) vaccine which will provide passive immunity to the baby.
Vaccine timing:
COVID (PFIZER) vaccine can be given at any stage of pregnancy.
Some women may prefer to avoid the first 12 weeks of pregnancy but the risk of delaying vaccination versus the potential of pregnant women becoming seriously unwell with COVID infection need to be considered.
There is no need to delay vaccination during breastfeeding – nor is there a need to stop breastfeeding during vaccination.
If planning a pregnancy or undergoing fertility management there is no need to delay vaccination. There is no evidence that vaccination will affect fertility.
Summary:
All pregnant women should come to an informed decision about COVID vaccination in pregnancy and be supported even if they decline vaccination.
Some women may prefer to delay vaccination until later in pregnancy or after birth.
Most women who contract COVID 19 in pregnancy will have no or mild symptoms.
But a minority will suffer a severe illness requiring ICU or ventilatory support.
There is an increased risk of premature delivery and a doubling of the stillbirth risk with COVID infection in pregnancy.
Other considerations such as occupation and exposure sites also need to be taken into account.
At the time of writing, there was no preference for vaccine role out to pregnant women.
Ongoing research is occurring with updates occurring frequently.
REFERENCES:
Royal College of Obstetricians and Gynaecologists – COVID vaccine in pregnancy.
Royal Australian and NZ College of Obstetricians and Gynaecologists – current guidelines.
ATAGI – Australian Technical Advisory Group on Immunisation.