SINGAPORE - Pregnant and breastfeeding women should get vaccinated to protect themselves and their babies from Covid-19, as real-world data has shown that this is not only safe but is also beneficial to both mother and child, said specialists here.

With the emergence of new Covid-19 variants and a resurgence of community-transmitted cases, there is reason to vaccinate pregnant women, who are at higher risk of developing complications from Covid-19 than non-pregnant women, they added.

Vaccination also protects the baby, said the College of Obstetricians and Gynaecologists Singapore (COGS) and the Obstetrical and Gynaecological Society of Singapore (OGSS) on Thursday (June 3).

Studies in other countries have shown that pregnant women who get Covid-19 are more likely to require intensive care or invasive ventilation, such as a breathing tube inserted into the windpipe, said Dr Lim Min Yu, president of OGSS.

This puts the baby at higher risk of premature birth and stillbirth, and he may also need intensive care.

"It's for these reasons that we feel it is imperative to encourage our pregnant women to be vaccinated," Dr Lim said.

Moreover, antibodies that the women produce after vaccination are transferred to the babies before birth, as well as to breast milk. This offers protection to the babies, though the extent and duration of this protection is unclear at this stage, he said.

COGS and OGSS said the vaccines are safe for breastfeeding mothers, with none of the vaccine components passing into the breast milk.

They added that the vaccines are also safe for women who are planning to conceive.

COGS and OGSS issued a joint advisory and guidelines on Thursday, two days after the authorities here said it was safe for pregnant or breastfeeding women to get vaccinated.

Pregnant women who are older, overweight or obese, or who have conditions such as diabetes or high blood pressure, are at an increased risk of developing serious complications, the advisory said.

Pregnant women will be able to register and book a vaccination appointment from June 4 if they are part of the population group eligible for vaccination.

Adults aged 40 to 44 can now register for their Covid-19 jabs. Those aged 45 and above were included in previous phases of the national vaccination drive.

Pregnant women were among those advised previously to hold off on receiving the shots, as large-scale clinical trials on the Covid-19 mRNA vaccines have not involved such volunteers.

COGS and OGSS said a recent study of about 4,000 women in the United States "demonstrated safety of the mRNA Covid-19 vaccines (Pfizer and Moderna), with no increased risks of adverse pregnancy outcomes nor any obvious adverse events".

Dr Lim said that, currently, the main published data available on Covid-19 vaccines and pregnancy is on the two mRNA vaccines that are currently being used here, and that there is no safety data yet for the use of the Sinovac inactivated vaccine on pregnant women.

It is not clear why pregnant women are more prone to becoming severely ill with Covid-19.

Dr Lim said it could be due to the changes that women experience in pregnancy, such as increased heart rate and increased oxygen consumption.

For instance, their lung capacity gets affected by a growing uterus, their immune system also changes and there is an increased risk of developing blood clots.

He said that pregnant women can discuss the vaccination with their doctor.

"It's mainly to ascertain that they don't have any of the risk factors that would preclude them from vaccination, but those risk factors are actually the same as for the general population."