Virus unlikely to spread to children of Covid positive pregnant women: Study

As researchers race to understand the effects of COVID on pregnancy and babies, these findings offer good news for expectant parents.

“Analysis suggests infection was uncommon in babies born to women with COVID-19,” said Kate Woodworth, a medical epidemiologist at the Centers for Disease and Prevention.

Nevertheless, a pregnant woman with COVID is at risk of developing serious illness, which can have negative health consequences for her unborn child, even if the baby is born COVID-free. Recent studies have linked COVID-19 infection during pregnancy to both preterm labor and stillbirth.

The CDC released a study in September that found the rate of mother-to-child transmission was less than 4%. Another study published last February looked at data from more than 4,000 women in the US and UK, with Covid-19 newborn registries estimating it is even lower – around 2%.

Research indicates that this is related to the lack of the virus in the potential mother’s bloodstream. SARS-CoV-2 is often not present in blood samples, indicating that it does not usually enter the bloodstream of an infected person. In one peer-reviewed study, for example, only 6% of patients who visited the emergency room with COVID-19 had the virus in their blood. Other recent data suggest that the viral presence in the blood may be associated with more serious disease.

“For [Covid-19] To reach a pregnant fetus, it has to circulate in the bloodstream,” said David Schwartz, a medical epidemiologist and pathologist who most recently taught at the Medical College of Georgia at Augusta University. [Covid-19] There isn’t an agent that circulates in the bloodstream very often, there aren’t going to be many women whose uterus, placenta, and babies are exposed to the virus.”

Of the small number of newborns who tested positive at birth, the CDC said most infections in studies have been found to be mild or asymptomatic. The World Health Organization has reported similar findings.

Recent work by Schwartz has focused on the adverse effects of COVID on pregnancy. He stressed that there are still many unknowns. For example, most studies on the transmission of COVID from pregnant women to their newborns took place before the emergence of both the Omicron and Delta types.

Schwartz and health experts from 12 different countries recently teamed up to analyze placental damage caused by a virus called placentitis. Damage to the placenta may offer some explanation for why adverse fetal outcomes sometimes occur, Schwartz and colleagues found in a study published last August. Placental damage can help facilitate transmission of the virus, but, perhaps of greater concern, it can also starve the baby of essential oxygen and nutrients.

Zika Dangers

Dennis Jamieson, chief of gynecology and obstetrics at Emory Healthcare in Atlanta, Georgia, said that, in most cases, SARS-CoV-2 transplacental transmission from the placenta doesn’t hold true for every virus. For example, the Zika virus is extremely dangerous for pregnant women because it can more easily cross the placenta and cause serious problems for the fetus, including birth defects such as microcephaly and brain damage. Such complications can occur even when maternal Zika symptoms are mild.

So far, it appears that COVID-19 behaves similarly to the flu during pregnancy, Jamieson said. The flu is another virus that is rarely transmitted to the fetus. As with the flu, pregnancy problems are more closely linked to pregnant women becoming ill than transmission of the virus to their unborn child.

Flu vaccines are strongly recommended for pregnant women, not only because they protect expectant mothers from serious illness, but because antibodies from the vaccine travel through the placenta to help boost the baby’s immunity. before they are old enough to take the shot themselves. There is evidence that the same positive effect may occur with COVID-19 antibodies, which provide some level of protection against the virus.

A peer-reviewed study from Weill Cornell Medicine that analyzed cord blood samples from more than 100 pregnant women during 2021 found that those who were vaccinated during pregnancy had antibodies a few days after their first dose. Production started. Exactly two weeks later, they began to transfer what is known as “passive immunity” to their children.

This means that even if an infant is unlikely to catch COVID-19 in the womb, it will still be protected from the virus once it enters the world.

“Most kids who test positive are fine,” Schwartz said. “But all of these things can be prevented rapidly by getting vaccinated and promoted.”

This story has been published without modification in text from a wire agency feed. Only the title has been changed.