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Singapore became the first country in Asia to start its COVID-19 vaccination campaign, which was launched in December 2020. But while vaccination is generally encouraged, it is entirely voluntary. Today, the global drive to get inoculated is extensive and aggressive, especially with the rising concern over new variants of the virus that causes COVID-19. 

Is COVID-19 vaccination safe for pregnant women and breastfeeding mothers, and does it affect female fertility?

In the words of the World Health Organization, the COVID-19 vaccine products “that have been assessed by the WHO Strategic Advisory Group of Experts on Immunization can be offered to women.” It is recommended that pregnant and breastfeeding women “be provided with information about the risks of COVID-19 in pregnancy, the likely benefits of vaccination in the local epidemiological context, and the current limitations of safety data in pregnant women.”

We’re still not out of the woods completely and evidence is continually being gathered on the virus and the benefits vs. risks of vaccination. Meanwhile, we encourage all women to read on and learn more about the following crucial topics to help them make informed decisions: 

  • COVID-19 risks in pregnant women
  • COVID-19 vaccination in pregnant women
  • COVID-19 vaccination and breastfeeding
  • COVID-19 vaccine and fertility
  • COVID-19 vaccination reminders for women

COVID-19 risks in pregnant women

Pregnant women have been found to be significantly at higher risk for developing severe COVID-19 complications as compared to non-pregnant women. 

As with all infections, COVID-19 adds to the potential complications in pregnant women who are older, overweight, or have conditions such as diabetes and high blood pressure. The risks may lead to complications that merit admission into the intensive care unit (ICU) or require mechanical ventilation, and in severe cases, even death. 

Babies in the womb are also at risk for preterm birth. These neonates often require admission into the neonatal intensive care unit (NICU), and some are just too small and underdeveloped to survive.

There’s yet to be a clear-cut answer as to why pregnant women are more prone to developing severe Covid-19 symptoms. Although experts say that it could be due to the changes that women go through during pregnancy, such as increased heart rate and increased oxygen consumption. For one, lung capacity can be affected by a growing uterus.

The childbearing women’s immune system also goes through changes that may pose a greater risk of developing blood clots. Click To Tweet


With the emergence of new COVID-19 variants and a resurgence of community-transmitted cases in Singapore, health authorities strongly recommend the vaccination of pregnant women in efforts to curb infections and complications.

COVID-19 vaccination in pregnant women 

Large clinical trials on COVID-19 vaccines may not have included pregnant women. But real-world data in almost 4000 women in the US has shown the safety of mRNA COVID-19 vaccines (e.g. Pfizer and Moderna). These vaccines have not been linked to increased risks of adverse pregnancy outcomes, or any adverse events.

There have been concerns about blood clots with adenovirus vector vaccines (e.g. AstraZeneca).  But these risks are very small compared to the actual risks of developing serious COVID-19 complications during pregnancy. Currently, the adenovirus vector vaccine is not available in Singapore. What we do use in the country are mRNA vaccines (Pfizer and Moderna). 

There have been reports of rare blood clots (cerebral venous sinus thrombosis) in some people who received mRNA vaccines. But it’s worth noting that this complication is extremely low, and there’s no evidence which shows that it increases the risk after receiving the mRNA vaccine. What remains true is that the risk of blood clotting is considerably higher if a pregnant woman is infected with COVID-19.

Besides the protection you give yourself, you also passively transfer the antibodies you develop to your baby through the placenta. In the studies conducted to assess maternal transfer of antibodies, the Covid-19 vaccination was given during the third trimester. The extent of protective effect is still being studied. 

COVID-19 vaccination and breastfeeding

We all know that breast milk can contain components of whatever the mom is consuming or is exposed to. As such breastfeeding mothers are deeply concerned about the safety of the COVID-19 vaccine—not just for their own sake but mostly their child’s health. 

It’s a good thing that many experts report that getting the WHO-screened COVID-19 vaccines now available are safe for breastfeeding mothers—experts that include the Centers for Disease Control and Prevention (CDC). There is no need to stop breastfeeding right after vaccination so there is no interference to breastfeeding schedule. 

Studies likewise show that none of the vaccine’s components can be passed through breast milk. Getting COVID-19 vaccinated while breastfeeding would still benefit the mother. In turn, vaccinated mothers develop antibodies, which are passed on to breast-fed kids. However, the nature and extent of the protection provided by the vaccine to children who consume mother’s milk are still being investigated at this point.

COVID-19 vaccine and fertility

There are those who say that getting vaccinated may affect women’s fertility—a MYTH already debunked by many global medical authorities, including Johns Hopkins. To date, there is no evidence to suggest that the COVID-19 vaccine can affect a woman’s ability to conceive. 

There are no reports of female infertility occurrences after getting inoculated, thus far. In one of the COVID-19 vaccine clinical trials, 23 female participants in the study got pregnant after being inoculated voluntarily with the Pfizer-BioNTech vaccine. As of now, those participants reported no adverse effects.

For their own peace of mind and safety, women who are trying to conceive or are undergoing fertility treatments should consult with their doctors before getting vaccinated but pre conception vaccination is now highly encouraged.

COVID-19 vaccination reminders for women

As a general rule, women should seek individualised risk-based pre-vaccination counselling. Ask your healthcare professional or doctor to provide you with information regarding the benefits and possible risks of the COVID-19 vaccine with regards to your condition. The counselling should include occupational exposure, underlying medical risk factors that would increase severity of Covid in pregnancy Eg underlying respiratory conditions, obesity, hypertension and diabetes, the expected benefits of vaccination and possible risks Eg small risk of anaphylaxis or myocarditis.  

There is no need to produce an obstetrician’s letter before vaccination at the national vaccination centre. Both the mRNA vaccines Moderna and Pfizer are approved by the ministry of health in pregnancy. 

Meanwhile, in the absence of other contraindications, breastfeeding women are encouraged to get vaccinated.

Preconception vaccination is also encouraged in women who are in their reproductive age.  Click To Tweet


For those who get pregnant and have received their first dose, you may opt to continue with the second dose at a later date although there is little evidence to support delaying the second dose or completing the vaccination process only after the first trimester of pregnancy. Still, do take up the matter with your OB-GYN during your regular prenatal visits. Based on feedback from patients, vaccine hesitancy is still fairly high amongst the pregnant population. Because it is such a precious and important time of development for the fetus it is understandable that mothers are very cautious about medications they receive. Hopefully with more data published in the future, mothers can then be reassured to take that step to protect themselves and their babies. 

Lastly, regardless of the vaccination status, pregnant women must continue to follow the usual safety protocols—social distancing, frequent hand washing, and wearing face masks—as a precaution. And if the pregnant individual chooses not to be vaccinated, all her family members and contacts are strongly encouraged to be vaccinated to reduce transmission risks to her. 

As more of Singapore’s population are now getting vaccinated, the likelihood of the virus spreading and wreaking havoc gets slimmer and slimmer, the safer we’ll all be as a society. Our government and health experts strongly recommend that all pregnant and breastfeeding women discuss their options on COVID-19 vaccination, urgently, with their obstetricians or health care provider.

To help you make an informed decision, or answer any more of your questions, you may call +65 6254 2878 (Thomson) to book a consultation with Dr Pamela Tan, or simply drop an enquiry here.

Dr Pamela Tan
About Dr Pamela Tan

Dr Pamela Tan is a board certified obstetrician and gynecologist in Singapore. She finished her undergraduate studies at the National University of Singapore and earned her post-graduate degree at the Royal College of Obstetricians and Gynaecologists in the UK. She is an accredited specialist by the Specialist Accreditation Board (Ministry of Health), and a fellow of the Academy of Medicine, Singapore. She subspecialises in colposcopy and is certified to perform Level 3 minimally invasive keyhole surgeries such as laparoscopic hysterectomy, myomectomy and cystectomy. Dr Pam also supports the natural birthing method and she strives to provide a personalised care and treatment for each patient.