Is there a link between COVID-19 and miscarriage? Experts weigh in

There is a lot that experts still don’t know about the impact of COVID-19 on pregnant women and their babies. But a disturbing new case report has linked the virus to a woman’s miscarriage.

The report, which was published in the Journal of the American Medical Association (JAMA), details the story of an unidentified pregnant woman in her second trimester who received care at Switzerland’s Lausanne University Hospital. The 28-year-old woman had a fever of 102.5 degrees, along with muscle pain, fatigue, mild pain with swallowing, diarrhea and a dry cough. She tested positive for COVID-19, was prescribed acetaminophen, and sent home. But she returned to the hospital two days later, after she started having uterine contractions.

The woman went through 10 hours of labor and delivered a stillborn baby on March 20. The case report notes that, while the woman’s nasopharyngeal swab was positive for SARS CoV-2, the virus that causes COVID-19, blood and vaginal swabs sampled during labor were both negative for the virus.

COVID-19 tests given to the baby were also negative. But two swabs and biopsies from the placenta that were taken close to the umbilical cord tested positive for COVID-19. The researchers concluded that while the baby did not appear to have been infected with COVID-19, the mother and her placenta were infected with the virus — and that may have caused the miscarriage.

“Absence of the virus is not surprising given the stage of fetal development and short time of maternal infection,” the researchers wrote. But, they added, “whether SARS CoV-2 crosses the placental barrier warrants further investigation.”

If you’re pregnant, it’s only natural to have questions about the health risks you and your baby may face. Here’s what you need to know.

Can COVID-19 increase the risk of miscarriage?

There is limited research on COVID-19 and its impact on pregnant women but, so far, this is the first research paper to link miscarriage with the virus. One small study published in the Lancet in May analyzed data on seven pregnant women with COVID-19 who were seen at a hospital in Wuhan, China. All seven mothers, who were in their third trimesters, had their babies and were eventually discharged from the hospital.

Another small study published in the Lancet in mid-March studied nine pregnant women in China with confirmed cases of COVID-19. Those women all had healthy babies during the study, and the virus was not detected in their breast milk, cord blood or amniotic fluid.

The woman in the new JAMA case report had a placenta infection, which is rare in pregnancy, Dr. Michael Cackovic, a maternal-fetal specialist at the Ohio State University Wexner Medical Center, tells Yahoo Life. “They are a common cause of preterm labor and preterm birth, accounting for as high as 40 percent of some preterm births,” he says.

Cackovic stresses that underlying risk is important to take into account with this report. “The background risk of miscarriage is generally around 20 percent but can be as high as 30 to 35 percent in some populations,” he says. The woman was obese, the case report noted, and had a fever — both of which can increase the risk of miscarriage, Cackovic says. However, a fever is a common symptom of COVID-19, which Cackovic recognizes is tricky. “It’s hard to separate infection from the fever in this case, as fever can spark an inflammatory response leading to loss or preterm birth,” Cackovic says.

Is COVID-19 causing an increase in miscarriages?

Again, it’s hard to say. “I have not noticed an increase in either miscarriage or preterm birth over the past three months,” Cackovic says. But Dr. Jessica Shepherd, an ob-gyn in Texas, says she has noticed an increase in miscarriages, and some of her colleagues have, too. “It’s been a hot topic among obstetricians,” she says.

Dr. Sherry A. Ross, an ob-gyn and women’s health expert at Providence Saint John’s Health Center in Santa Monica, Calif., tells Yahoo Life that her practice recently had a patient who had a stillbirth at 34 weeks of pregnancy with no obvious cause. “There are a lot of questions surrounding that and questions if it might be related to COVID-19,” she says.

Some women are also reporting on Facebook pregnancy groups that their doctors have mentioned an increased risk of miscarriage. Still, there isn’t published data to back this up.

“There is unpublished data that has been floating around for a couple of months that found there is an increased risk of miscarriage in women who have COVID-19,” Dr. Lauren Streicher, a professor of clinical obstetrics and gynecology at Northwestern University Feinberg School of Medicine in Chicago, tells Yahoo Life. “It’s not well documented, but it certainly is a concern.”

It’s unclear why there might be a link, but COVID-19 causes an increased risk of blood clots, and those can form in the placenta or umbilical cord, leading to miscarriage, Streicher points out.

Some research has indicated an increased risk of miscarriage in pregnant women who had either Middle East respiratory syndrome (MERS) or severe acute respiratory syndrome (SARS), which are both coronaviruses. One small study that was published in the Lancet in February analyzed data from 12 pregnant women who were infected with SARS during the 2002-2003 pandemic. Of those women, 57 percent had a miscarriage in their first trimester. Of the remaining women, 40 percent had fetal growth restriction (meaning their babies didn’t grow normally) and 80 percent had a preterm birth. The JAMA case report also cited data that found that 40 percent of women infected with MERS had either fetal growth restrictions or miscarriage.

But again, these findings were for SARS and MERS, not COVID-19. “With COVID-19, we really don’t know the risk,” Streicher says. Women’s health expert Dr. Jennifer Wider agrees. “More studies are needed,” she says.

What should you do if you’re pregnant?

Currently, the Centers for Disease Control and Prevention says that pregnant women should follow the same precautions as everyone else, including avoiding people who are sick or have been exposed to COVID-19, washing their hands regularly and cleaning and disinfecting commonly touched surfaces frequently.

The CDC says that mother-to-child transmission of coronavirus during pregnancy is “unlikely” but notes that a “very small number” of babies have tested positive for the virus soon after birth. “However, it is unknown if these babies got the virus before or after birth,” the CDC says online.

The American College of Obstetricians and Gynecologists released a statement in early April that backed up the CDC’s recommendations. Neither organization has linked COVID-19 to an increased risk of miscarriage.

However, Streicher says, that doesn’t mean the risk doesn’t exist — the data just isn’t there. “My recommendation has been that, in the absence of data, you should be ultra-careful,” she says. “You should assume that every single person you come across has COVID-19 and do appropriate social distancing.”

Wider also recommends that pregnant women be especially cautious. “Pregnant women need to be aware of a potential risk and take precautions,” she says. Shepherd, the Texas ob-gyn, specifically recommends flagging any unusual symptoms to your doctor, even if you’re unsure if it’s an issue.

“We have very little data, other than anecdotal data, but this is a valid concern,” Streicher says.

For the latest coronavirus news and updates, follow along at According to experts, people over 60 and those who are immunocompromised continue to be the most at risk. If you have questions, please reference the CDC’s and WHO’s resource guides.

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