Follow all of PopSci’s COVID-19 coverage here, including travel advice, pregnancy concerns, and the latest findings on the virus itself.

Because of the coronavirus’ novelty to humans, there are many issues that we still haven’t pinned down—like how many different ways the virus can be transmitted and whether its spread will slow when warm weather arrives.

How COVID-19 affects pregnancy is another area where there’s little that scientists know for certain.

“At this time there are more questions than there are answers,” says Ashley Roman, director of the Division of Maternal Fetal Medicine at NYU Langone Health. “This a rapidly evolving situation [and] we’re being bombarded with new data on a daily basis.”

We aren’t completely in the dark—there are some initial reports from China on pregnant women who were diagnosed with COVID-19. And scientists can extrapolate a bit from what we know about other viruses, including the related coronaviruses SARS and Middle East Respiratory Syndrome (MERS).

These are some of the questions about the new coronavirus that scientists are racing to answer:

Can a pregnant person pass the infection on to their fetus or newborn?

The main way that COVID-19 spreads from one person to another is through droplets that are launched into the air when a sick person coughs or sneezes. However, certain pathogens—like the Zika virus—can spread through the placenta or breast milk, or during childbirth.

In early February, health officials became concerned that the new coronavirus could travel this way too. A woman in Wuhan with confirmed COVID-19 gave birth to a baby who tested positive for the virus 36 hours later.

However, shortly afterwards researchers in China reported in the journal Translational Pediatrics that throat swabs from nine newborns born to women infected with COVID-19 had all tested negative for the coronavirus.

Another team in China also published a report on another nine women who contracted COVID-19 and developed pneumonia during the third trimester of pregnancy. Throat swabs from the newborns and samples of the mothers’ breast milk, amniotic fluid, and cord blood all tested negative for the virus.

This very small group of cases suggests that there’s currently no evidence that COVID-19 is being spread in utero or soon after birth, the researchers wrote in The Lancet. Additionally, there haven’t been any reports of SARS or MERS being transmitted this way. But we won’t know for sure until scientists have tracked a much larger number of pregnant people with COVID-19, including people who caught the disease during earlier stages of pregnancy.

Are pregnant people more vulnerable to COVID-19?

When someone is pregnant, their immune system is suppressed somewhat so their body won’t reject the fetus. Because of this and other changes to their bodies (including hormonal shifts), pregnant people are more susceptible to certain infections, such as urinary tract infections.

Some respiratory infections—including influenza, SARS, and MERS— can also cause pregnant people to become more seriously ill than others who catch the disease. On the other hand, there are also coronaviruses that cause the common cold and have been circulating among people for decades, and they haven’t been reported to cause more severe illness in pregnant people, says Sallie Permar, a professor of pediatrics, microbiology, and immunology at the Duke University School of Medicine.

Based on the very limited information that we have right now, it doesn’t appear that pregnant people are more likely to catch COVID-19 than anyone else or to experience severe symptoms, Permar says.

All of the women that researchers tracked for the report published in The Lancet had developed pneumonia, but none of them became severely ill or died. “The clinical characteristics of COVID-19 pneumonia in pregnant women were similar to those of non-pregnant adult patients with COVID-19 pneumonia,” the researchers wrote.

Can COVID-19 affect a developing fetus?

Some diseases have profound consequences on a pregnancy that range from early labor to congenital abnormalities or miscarriage. So far, there haven’t been any reports of COVID-19 causing people to miscarry, Permar says. It’s not clear yet whether COVID-19 has any impact on early pregnancy.

We do know, however, that SARS and MERS do not appear to increase the risk of congenital abnormalities. “In both of those outbreaks, the primary risks in pregnancy appeared to be the risk of more severe disease in the mother and the risk of preterm labor,” Roman says.

According to the Centers for Disease Control and Prevention, there are some reports of babies born to mothers infected with COVID-19 facing issues such as premature birth. However, it’s not clear whether these problems were related to the coronavirus.

Will vaccines and drugs to treat COVID-19 be safe for pregnant people?

There is not currently a vaccine or antiviral drug to combat the new coronavirus. Treatment right now is focused on helping the sick person cope with the symptoms of COVID-19. That can mean helping them stay hydrated, giving them medicines to bring their fever down, or giving them oxygen if they are having trouble breathing.

“If a pregnant individual does get diagnosed with COVID-19 and does end up having to seek medical care, the medical care would in general be the same,” Permar says. The main difference is that doctors might also monitor the fetus by tracking its heartbeat over the course of the infection.

Generally, live vaccines—which use a weakened form of the virus—aren’t recommended for pregnant people because of the theoretical risk that the virus could infect the fetus. Live vaccines include the measles, rubella, and chickenpox vaccines.

However, most other vaccines are safe for pregnant people and protect against diseases such as influenza, tetanus, diphtheria, and whooping cough. These include vaccines that use a killed version of the virus or only include a piece of the virus, which renders it unable to infect human cells and reproduce inside a human.

“What we have come to realize over the last couple decades is how important it is for pregnant women to get vaccines,” Permar says. “Many of the types of vaccines that are being developed for coronavirus should be the type that cannot replicate as a full live virus vaccine.”

This means that when a vaccine for COVID-19 does become available, it’s likely to be safe in pregnant women—but researchers will need to confirm that this is the case.

Similarly, there are certain antiviral drugs that are known to be safe for pregnant people and fetuses. In fact, one of the medications being tested as a treatment for COVID-19—a cocktail of the drugs lopinavir and ritonavir—is often used to treat pregnant people with HIV and prevent the virus from reaching the fetus or newborn.

But in many cases, when a new vaccine or drug is being developed, the clinical trials used to test their safety and effectiveness often don’t include pregnant people or children—despite the fact that these populations are especially vulnerable to many diseases. So when the medicines first hit the market, it isn’t clear how safe they are for these populations, Permar says.

It will be vital for researchers to consider pregnant people early on in their safety evaluations so that they can benefit from any new treatments or vaccines, she says.

What can pregnant people do now?

Any insights we have right now about how the coronavirus affects pregnancy are based on very limited, preliminary data. Scientists will need to monitor many more cases over longer periods of time to figure out how COVID-19 differs from other infections.

“As we get more experience with COVID-19 and pregnancy, we’ll get more answers,” Roman says. For now, though, if you’re pregnant and concerned about COVID-19, Roman and Permar do have some advice:

  • Follow the standard steps for preventing COVID-19 transmission. Wash your hands frequently and thoroughly, especially after coming into contact with other people or objects that people frequently touch, such as elevator buttons. Use alternatives to shaking hands like the elbow bump. Keep your distance—at least 6 feet—from someone who is coughing and seems sick.
  • Check the CDC website for up-to-date information about the virus, testing, and treatment for COVID-19, and guidelines for breastfeeding if you do become ill.
  • If you don’t feel well, stay home and isolate yourself from friends and family if at all possible. Be in touch with your OBGYN if you feel sick to determine if you need any additional care or monitoring.