A new study has revealed the deadly toll COVID-19 can take on the babies of unvaccinated pregnant women, underlining the importance of vaccination for expecting mothers.
The peer-reviewed research published in the journal Archives of Pathology & Laboratory Medicine on Feb. 10 examined 68 perinatal deaths in 12 different countries.
The analysis shows that among 64 stillborn cases and four babies that died within seven days of being born, all the mothers had COVID-19 during pregnancy and were unvaccinated.
The researchers observed what they called “SARS-CoV-2 placentitis”. This is an uncommon complication in pregnant individuals with COVID-19 that causes unusual inflammation of the placenta, increased fibrin — a blood-clotting protein — and the death of body tissue in the protective cell layer of the placenta.
The study authors noted that the virus had caused widespread and severe destruction of the placenta — an organ that develops in a woman’s uterus during pregnancy and provides oxygen and nutrients to the growing baby.
Dr. David Schwartz, a perinatal pathologist and epidemiologist in Atlanta, Georgia, and the study’s lead author, said he was surprised to see such a high level of destruction. The average placenta was 77.7 percent destroyed by SARS-CoV-2 placentitis.
“The placenta is the sole source of oxygen and nutrition for the fetus. The severe extent of placental destruction we are seeing renders it incapable of performing its function of supporting the fetus, and it becomes incompatible with life,” he told Global News.
Dr. Graeme Smith, head of obstetrics and gynecology at Kingston Health Sciences Center in Queen’s University, said the stillbirths were likely caused by the damage done to the placenta rather than the baby getting infected with the virus.
“There may also be an increased chance of growth restrictions,” he said, adding that it’s important to monitor pregnant women, not just during their infectious stage, but also after they recover, just to make sure the baby is growing appropriately.
While worrying, occurrences of SARS-Cov-2 placentitis are rare.
However, a growing body of research suggests that pregnant women are at an increased risk of severe illness from COVID-19, and getting the disease during pregnancy increases the risk of premature birth, stillbirth and other maternal and neonatal complications.
A peer-reviewed study published in the British Medical Journal last month, including nearly 5,000 pregnant women infected with COVID-19, found that “severe complications,” such as critical care admission, stillbirths, and early neonatal deaths, were more common in those who were unvaccinated compared with those who were vaccinated.
Looking at the Canadian data, Dr. Darine El-Chaar, a maternal fetal medicine specialist at the Ottawa Hospital, said there has been about 1 per cent risk of stillbirth among all COVID-19 infected pregnancies, and this rate has remained fairly steady throughout the course of the pandemic in Canada.
“I think it is important to keep in mind that these are still very rare outcomes,” she said.
El-Chaar said other risks associated with COVID-19 that are more specific to pregnancy have been an increase in preterm birth rate, which could be either due to the inflammation of the infection or because of a need to deliver the baby early because of the severity of illness.
There has also been a higher risk of potentially requiring a cesarean section for delivery among pregnant individuals who have COVID-19, she added.
Vaccinated moms can protect babies
In January, a group of hospitals in Ontario reported a “disturbing” trend of infant hospitalizations due to COVID-19. The Children’s Hospital of Eastern Ontario (CHEO) in Ottawa noted that all the infants admitted since mid-December had unvaccinated mothers.
“Infants are especially at risk because they have an immature immune system that has difficulty combatting disease,” a joint statement by Toronto’s Hospital for Sick Children, McMaster Children’s Hospital, CHEO and Kingston Health Sciences Centre said.
“And if the mother has not been vaccinated or infected, they do not have the protection of maternal antibodies transferred during the third trimester of pregnancy,” the statement added.
In Canada, public health officials have stressed that pregnant women should get vaccinated against COVID-19 since they are at an increased risk of severe outcomes.
In an official health advisory issued in September 2021, the U.S. Center for Disease Control and Prevention (CDC) recommended urgent action to accelerate primary vaccination for people who are pregnant, recently pregnant (including those who are lactating), who are trying to get pregnant now, or who might become pregnant in the future.
Canada’s National Advisory Committee on Immunization (NACI) recommends that people who are planning a pregnancy, are currently pregnant or are breastfeeding should get a complete series with an mRNA vaccine and a booster dose when eligible.
“There’s no evidence that any vaccines, including COVID-19 vaccines, cause fertility problems,” NACI says.
Dismissing baseless claims circulating online, experts say based on the data collected, COVID-19 vaccines have not shown an increased risk of stillbirth, miscarriage or birth defects.
Meanwhile, some studies show that mothers who were vaccinated against COVID-19 during pregnancy can pass on antibodies to their newborns through breast milk and the placenta.
So far, no COVID-19 vaccines have been approved for children below the age of five, including infants.
“From the baby’s point of view, we know that the antibodies that moms produce, specifically IgG, crosses the placenta and it provides protection to the baby for probably about six months after delivery,” said Smith.
Schwartz said their latest findings underscored the importance of COVID-19 vaccines for expecting mothers and their babies.
“Clearly, vaccination of pregnant women is a life-saving procedure for the mother and so we think that it’s potentially a life-saving procedure for the fetus as well.”