Should pregnant women get the Covid-19 vaccine?

Women who have gotten pregnant after receiving their first dose of a Covid-19 vaccine do not appear to have had their pregnancy or fetus affected by the vaccine. — Wikimedia Commons

There are about 500,000 births annually in Malaysia.

As some pregnancies end up in miscarriages, it would be reasonable to assume that there are about 600,000 pregnancies annually.

The jury is still out on some pundits’ prediction that there will be an increase in pregnancies this year (2021) due to the movement control order, although the Chief Statistician did report that there was actually a decrease in the number of babies born in the first quarter of the year.

The information in this article is from international reviews.

The current evidence suggests that the likelihood of pregnant women getting Covid-19 is similar to that of other healthy adults.

About two-thirds of the infected pregnant have no symptoms (i.e. are asymptomatic).

Most of the infected have mild symptoms like that of the common cold or flu.

However, a small number can get moderate to severe disease.

Pregnant women with Covid-19 may be at increased risk of severe disease compared to the non-pregnant, especially during their last trimester (three months) of pregnancy.

As a precaution, the pregnant have been included in the list of those at moderate risk of Covid-19 in most countries.

No reported ill effects

Pregnant women in Malaysia are eligible to be registered for Covid-19 vaccination.

As vaccination is currently voluntary, it is their choice to either go ahead and be vaccinated, or await more information about the vaccines.

In my last column, I discussed how Covid-19 could potentially affect pregnant women and newborns.

Those factors are among those that should be considered when pregnant women make their decision as to whether or not to get vaccinated.

Pregnant women were not included in any of the clinical trials that tested the safety and effectiveness of the various Covid-19 vaccines.

This means that information about the effects of such vaccination in pregnancy is limited.

As such, no one can be 100% sure whether or not the vaccines will cause adverse events in pregnancy.

This uncertainty has to be considered against the risk of developing Covid-19 while pregnant.

A small number of women who received the vaccines in the trials did however subsequently became pregnant.

No safety problems were reported in those cases.

Data from the United States, where about 90,000 pregnant women have been vaccinated (mainly with the Pfizer/BioNTech and Moderna vaccines), have not raised any safety concerns.

Covid-19 vaccines do not contain ingredients known to be harmful to either pregnant women or the fetus.

Animal studies have also shown no evidence that the vaccine causes harm to the pregnancy.

Furthermore, pregnant women have been receiving vaccines like tetanus toxoid, influenza and pertussis, without any reported harm to their foetuses.

The Pfizer/BioNTech Covid-19 vaccine triggers an immune response with SARS-CoV-2 viral spike proteins produced within the body from mRNA (messenger ribonucleic acid) strands that are part of the vaccine.

The AstraZeneca/Oxford Covid-19 vaccine works the same way, except that it uses DNA (deoxyribonucleic acid) strands instead of mRNA.

The Sinovac vaccine is an inactivated vaccine, i.e. it consists of SARS-CoV-2 viral particles that have been killed.

These vaccines all do not contain the live virus, hence they cannot infect the pregnant woman or her foetus.

According to the Government, pregnant women in Malaysia will be offered the Pfizer/BioNTech vaccine, but not the AstraZeneca/Oxford or Sinovac ones.

Rare side effects

Vaccination is effective in preventing disease.Pregnancy naturally increases the risk of thrombosis, which would be further exacerbated if the woman gets Covid-19. — Positive ParentingPregnancy naturally increases the risk of thrombosis, which would be further exacerbated if the woman gets Covid-19. — Positive Parenting

Even if one gets infected with Covid-19 despite being vaccinated, the risk of severe disease, hospitalisation and death is minimised.

Vaccination itself will not cause Covid-19.

Side effects from vaccination are common in the general population.

They include pain at the injection site, muscle ache, headache, fatigue and joint ache.

Allergic reactions, which are very rare, occur in those with a history of allergy.

These side effects have not been reported to have affected pregnancy.

Media focus on blood clots (thrombosis) with Covid-19 vaccines have caused unnecessary anxiety and fear.

The European Medicines Agency estimates that the risk of cerebral venous thrombosis (CVT) after receiving the AstraZeneca/Oxford vaccine is 5.0 (on average from a range of 4.3 to 5.8) per million people.

University of Oxford Academic Clinical Fellow Dr Maxime Taquet and colleagues recently reviewed US data from more than a million people.

Of those diagnosed with Covid-19, the incidence of CVT was 39 per million people.

In those who received an mRNA Covid-19 vaccine (Pfizer/BioNTech and Moderna), the incidence was 4.1 per million.

The risk of CVT therefore, was 10 times higher in Covid-19 patients, compared with those who were vaccinated.

The normal risk of thrombosis in the pregnant in Malaysia ranges from 500 to 2,000 per million.

Vaccine timing

Vaccination early in pregnancy offers early protection.

As pregnancy lasts nine months, the question is whether there is still protection at the end of the pregnancy as there is still uncertainty about the duration of protection after completion of the two-dose vaccines.

Vaccination after the first trimester (three months) offers better protection against Covid-19, which has been associated with more complications in the third trimester.

The first trimester is a time when foetal development occurs and the risk of miscarriage is highest.

Although there is a lack of evidence that the Covid-19 vaccines affect foetal development, it is recommended that vaccination begins after the first trimester.

This prudent approach avoids suspicion of links, even if coincidental, between vaccination, pregnancy and foetal harm.

It is possible to continue the second vaccine dose in women who conceive soon after receiving their first dose.

However, the second dose can also be delayed until after the end of the first trimester.

The second dose of the current mRNA vaccines have been delayed up to 12 weeks after the first dose in several countries because of availability issues, without significant impact on protection of the recipients.

However, whether this effect in the general population is also applicable to the pregnant is an unanswered question.

There is currently no data on delaying the second dose with the Sinovac and Sputnik V vaccines.

This problem may be resolved by the single-dose vaccines, e.g. Johnson & Johnson and CanSino, which are yet to be registered in Malaysia.

Take home message

A discussion with your attending doctor will be helpful in addressing any questions about Covid-19 vaccination in pregnancy.

It is important to avoid anyone who has symptoms suggestive of Covid-19 even after vaccination.

It would also be prudent to adhere to the non-pharmacological interventions of:

  • Physical distancing, particularly in the third trimester
  • Face mask-wearing
  • Frequent handwashing with water and soap, or hand sanitising with minimum 60% alcohol-based hand sanitiser
  • Avoidance of crowds, confined spaces and close contacts
  • Proper coughing and sneezing etiquette
  • Staying home as much as possible, and
  • Seeking medical attention promptly when unwell.
Dr Milton Lum is a past president of the Federation of Private Medical Practitioners Associations and the Malaysian Medical Association. For more information, email The views expressed do not represent that of organisations that the writer is associated with. The information provided is for educational and communication purposes only and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
Article type: metered
User Type: anonymous web
User Status:
Campaign ID: 1
Cxense type: free
User access status: 0
Subscribe now to our Premium Plan for an ad-free and unlimited reading experience!

Next In Health

Chinese resort to traditional remedies to fight Covid-19
Newly discovered gene can rewind your heart's biological age
From tyre to tummy: Tyre microplastics absorbed by lettuce roots
The link between sexual and bladder health for women
Exercises that can help you channel your inner bunny
Injecting stem cells to treat this inherited cause of blindness
Dealing with fatty liver disease through your diet
Here's how to allergy-proof your home
This artificial pancreas could automate insulin delivery for diabetics
Simple ways to eat healthy this Chinese New Year

Others Also Read