For months, obstetricians, pregnant women and the people who love them have been asking: Can a pregnant woman pass COVID-19 to her fetus?
Based on a small study in China, the thinking was no. Now, based on research coming out of Italy, the answer could be yes.
That research has not been published yet, but researchers spoke about their findings in a virtual conference earlier this month. Of the 31 babies born to women with COVID-19 when they delivered, two infants tested positive for the disease.
The Italian study tested the babies, placenta and umbilical cords as well as breast milk and tissue from the mother right at birth, which means that the baby might not have contracted the disease after birth.
"What they did find is different from what everyone else found before now," said Dr. Kaylen Silverberg, medical director of Texas Fertility Center.
Before this study, doctors were basing the assumption that babies could not get the virus in utero on a study of 33 women in China and three infected newborns, but those babies were tested on their second day of life, not at birth, and the cord blood, breast milk and placenta were all negative for the virus.
They also believed that COVID-19 would behave like other coronaviruses, such as SARS and MERS, which have not shown a vertical transmission of disease from a mom to a baby in utero.
This new study doesn’t present strong evidence of vertical transmission, but "it does raise a red flag," Silverberg said.
What all the studies have shown is that the babies who get the disease do well and recover.
For Silverberg’s patients who are looking for a definitive answer, he has to tell them he can’t provide that right now.
"All we have so far is a very limited amount of data," he said.
Dr. Crystal Berry-Roberts, an obstetrician/gynecologist at Austin Regional Clinic, said we don’t know from any of the studies what the risk is to the baby, but she does know that what doctors were telling patients in March, that there was no risk of vertical transmission, might not be correct.
She tells her patients, "we’ve identified that this is a possible concern," she said. "It’s been really hard to counsel patients that what I was telling them three months ago is not true today."
Information and risk factors will continue to evolve with this disease. COVID-19 hasn’t been around long enough to have gone through complete pregnancy cycles in a large number of women. It’s unclear what effects it could have in the first, second or third trimester, or if there might be long-term effects, which we might start seeing as the children of pregnant women infected with COVID-19 go through the first three years of life.
More research is being done. The National Institutes of Health is looking at 21,000 pregnant women’s medical records and studying the outcomes for them and their babies for the first six weeks of life to see if there are differences in mothers with COVID-19 and mothers without.
An International Registry of Coronavirus Exposure in Pregnancy has opened to track outcomes as well. Berry-Roberts is encouraging her pregnant patients to join that registry if they should become infected to give researchers information and to receive information from the researchers.
For patients who are not yet infected, she reminds them that there are things they can do to lessen their risks as well as their worry about the effects on their baby: social distancing, wearing a mask and washing their hands often.
Also, they should be aware of what the people they interact with are doing.
"Anyone residing with that pregnant person, they could be a risk factor for that patient if they are not practicing those measures and coming home and putting her at risk," Berry-Roberts said.
If a pregnant woman does contract the disease, Berry-Roberts said, that will change the level of care she will receive. Respiratory diseases are always a worry with pregnant women, as are some infectious diseases that have known lasting side effects when contracted as a fetus.
For pregnant women with COVID-19, more ultrasounds will be done on the baby, and doctors will intervene with COVID-19 treatments faster to make sure the mother’s breathing does not decline.
"She could get sick faster than someone who is not pregnant," Berry-Roberts said.
The Centers for Disease Control and Prevention recently added pregnant women as one of the known vulnerable populations for increased risk of severe illness.
Even with increased risk factors, Silverberg said he’s trying to keep his patients calm. This isn’t like Zika, which has a high risk of birth defects.
Instead, he reminds them to "avoid any risks you can avoid." That would mean doing things like working from home, picking up groceries curbside and not going inside a restaurant to eat.
"You’ve got to be smart, more cautious than the average person," he said.