TORONTO -- A new study has found that pregnant people were more likely to experience severe outcomes of COVID-19 and more likely to lose their baby if they weren't vaccinated.

Scottish researchers published their findings in the . They looked at a database involving 145,424 pregnancies in the country between December 2020 and October 2021.

The researchers found that 77.4 per cent of Scots who got COVID-19 while pregnant were unvaccinated. Unvaccinated pregnant people also made up 90.9 per cent of COVID-19-related hospital admissions and 98 per cent of admissions to the intensive care unit.

Getting COVID-19 while pregnant was also associated with an increased risk of stillbirths and newborn deaths. The study counted 11 stillbirths and eight newborn deaths, all of which involved mothers who were unvaccinated at the time of COVID-19 diagnosis.

Researchers examined the perinatal mortality rate, which refers to the rate of stillbirths and infant deaths less than a week after birth. During the study period, the perinatal mortality rate was 5.6 deaths per 1,000 births for the whole population. Among those who had COVID-19 at any point during their pregnancy, the mortality rate was 8.0 per 1,000.

For those who had COVID-19 within 28 days of giving birth, the perinatal mortality rate was a staggering 22.6 per 1,000 births.

"Our data add to the evidence that vaccination in pregnancy does not increase the risk of complications in pregnancy, but COVID-19 does," said first author Dr. Sarah Stock in a news release. "COVID-19 vaccination in pregnancy is crucial to protect women and babies from preventable, life-threatening complications of COVID-19."

COVID-19 was also associated with higher rates of preterm births. The preterm birth rate for those without COVID-19 was 7.9 per cent. For those who had COVID-19 at any point during their pregnancy, the rate was 10.2 per cent and for those who had COVID-19 within 28 days of giving birth, the rate was 16.6 per cent.

The researchers say the findings underscore the importance of vaccination for pregnant people, given that they are at a higher risk of serious outcomes from COVID-19.

"As cases of Omicron continue to rise, I strongly encourage all pregnant woman to take up the offer of a vaccination or booster as these will help protect them and their unborn child," study lead Aziz Sheikh said in a news release.

The researchers point out that COVID-19 vaccine uptake among pregnant people in Scotland has been lower than the general population, despite assurance from public health officials that the vaccine is safe. In October 2021, the vaccination rate among Scottish women was 77.4 per cent while only 32.3 per cent of pregnant Scots were vaccinated.

Vaccine uptake among pregnant Canadians also lags behind the general population, but not as much as in Scotland. that 85 per cent of residents 12 and over had been fully vaccinated. But among pregnant Ontarians, the vaccination rate was 71 per cent.

Canada's National Advisory Committee on Immunization as well as the have both recommended the mRNA COVID-19 vaccines for pregnant people. the vaccines are safe to receive while pregnant, citing data from the U.S. involving 35,000 pregnant people that found no safety concerns.