There's enough to worry about during a pregnancy, even without a pandemic. As the vaccine rollout continues, there's still concern over its impact on pregnancy. COVID-19 has added an entirely new layer of health anxiety for anyone expecting a child. That's why one of the biggest questions on many pregnant women's minds is if the COVID-19 vaccine is safe for them.

One drugmaker, Pfizer, will attempt to answer that question with a clinical trial of its coronavirus vaccine on pregnant women, the company announced last week. The results are not expected for months.

In the meantime, how can pregnant women decide whether they should get the COVID-19 vaccine? What about those trying to become pregnant or those who are nursing?

We asked CNN Medical Analyst Dr. Leana Wen for her advice. Wen is not only an emergency physician and public health expert; she's also a mother to 3-year-old son and a 10-month-old baby girl who was born during the pandemic.

CNN: Is the coronavirus vaccine approved for pregnant women?

Dr. Leana Wen: Technically, it's not, but it is an option for pregnant women. Here's why: The initial clinical trials did not include anyone who was pregnant or breastfeeding. Some women did become pregnant over the course of the trials, but because the research wasn't intended to study the vaccine's effect on pregnancy, there wasn't enough data for the Food and Drug Administration to authorize the shot for pregnant individuals.

Thousands of pregnant women have decided to take the coronavirus vaccine anyway. There have been no significant safety issues reported for these women. The US Centers for Disease Control and Prevention, the FDA and other experts have stated clearly that all pregnant individuals who are eligible should have the choice to receive the vaccine.

CNN: If the vaccine is not specifically tested in pregnancy, why would pregnant women take it?

Wen: Pregnant women are at higher risk for severe complications from COVID-19. There is a higher risk of being hospitalized and ending up in the ICU for pregnant women compared to non-pregnant women. The risk is further increased for pregnant patients with underlying medical conditions.

This is why medical organizations of OB-GYNs recommend that pregnant women are presented with the option of receiving the vaccine. The American College of Obstetricians and Gynecologists and the Society of Maternal and Fetal Medicine say that "given clear evidence of the dangers of COVID-19 in pregnancy, an absence of data demonstrating adverse effects associated with the vaccine in pregnancy, and in the interest of patient autonomy, ACOG and SMFM recommend that pregnant individuals be free to make their own informed decisions regarding COVID-19 vaccination."

CNN: So how do you recommend a pregnant woman make this decision?

Wen: Here are the two things I'd urge my patients to consider. First, what's your risk of exposure to COVID-19? Let's say that my patient is a nurse or respiratory therapist who is treating COVID-19 patients. That person has significant occupational exposure and getting the vaccine could protect her substantially during her pregnancy. Perhaps she has a spouse who is in a high-risk profession, or she lives in a household where she cannot keep physical distance from a family member with exposure risk. That would weigh in favor of getting the vaccine now.

Second, what's your risk of having a severe outcome if you were to contract COVID-19? Pregnancy alone already predisposes a person to more severe illness, and if you have other underlying medical conditions, you are at even higher risk, because risk is additive. Conditions like chronic lung, kidney or heart problems; diabetes; high blood pressure; and sickle cell disease could worsen the effects of coronavirus. Patients who are pregnant and with these underlying medical conditions could substantially benefit from the vaccine.

The bottom line is that any risk of an adverse effect from the COVID-19 vaccine is theoretical and the risks of COVID-19 infection are not. Based on what we know of the vaccine, there is no reason to believe that it will have a detrimental effect on the pregnancy or the long-term health of either the mother or baby. Lack of evidence doesn't mean it can't exist, but this kind of theoretical very low risk needs to be weighed against the real and potentially very high risk of a severe outcome from COVID-19.

This is the reason why many health care professionals who are pregnant have received the vaccine.

CNN: What about breastfeeding women?

Wen: We don't have data to say unequivocally that the vaccine is absolutely safe for breastfeeding people. However, there's no physiological reason as to why it would not be safe. Vaccines deemed to be of concern are those that contain live virus. The COVID-19 vaccines currently authorized in the United States -- and those that are in clinical trials here -- do not contain any live virus. In fact, if anything, the vaccines could have additional benefit to the baby. Some recent research suggests protective antibodies might be transferred to the baby via breastmilk.

CNN: You were pregnant at this time last year. Would you have gotten the vaccine if it were available to you when you were pregnant or breastfeeding?

Wen: I'm a health care worker seeing patients, with high-risk occupational exposure, and I also have asthma. So yes, I would have received the vaccine if it were available when I was pregnant. By the time the vaccines became approved, I had stopped nursing. As soon as I stopped nursing, I joined a vaccine trial. If I were still nursing and had the opportunity to get the vaccine, I would have no hesitation to take it.

CNN: What would you say to people who want to wait until there are clinical trials that prove the vaccine is safe for pregnant and breastfeeding women?

Wen: I'd say that's a reasonable choice, too. Everyone needs to make the best decision for themselves. A lot has been written about the ethics of vaccines in pregnancy. On the one hand, it makes sense to not include pregnant women in initial vaccine trials out of concern for them and their babies. On the other hand, it's not fair to deny an entire group of people the benefit of vaccines. The majority of health care workers are women of reproductive age, for example.

A lot of other vaccines actually have not specifically been tested in pregnancy but are routinely given because the proven benefits outweigh any theoretical risk. I think every patient needs to make the right decision for themselves and their family, in consultation with their health care provider.

It's important to note that pregnant and nursing women aren't in priority vaccination groups just by virtue by being pregnant or post-partum. If they are otherwise not prioritized to be vaccinated (for reasons such as a high-risk occupation or preexisting health condition), they need to wait their turn to be in the eligible groups, just like everyone else.

CNN: There's some misinformation out there about the vaccine and fertility. Can you clear this up?

Wen: Yes. There's absolutely no link between the coronavirus vaccine and fertility. This has been thoroughly debunked, and multiple medical societies around the world have come out with statements to this effect.

CNN: What would you say to women who are thinking of getting pregnant or trying to get pregnant? Should they get the vaccine?

Wen: If they are in priority groups to receive the vaccine and are able to, I'd say that they should. There's no reason to hold off. Of course, they should always consult with their health care provider, especially if they have medical procedures planned. For example, if they are planning IVF procedures -- maybe they don't want to time their vaccines for exactly the same day as their procedures to avoid simultaneous side effects.

Remember that the vaccines are very effective at preventing illness -- especially severe illness -- from COVID-19, but they are not 100% effective, and we still don't fully understand if those who have received the vaccine can transmit the virus. Even after receiving the vaccine, people should still use caution.

For pregnant patients, that means they can breathe a bit easier when going to their prenatal visits, but they should definitely still wear masks and abide by physical distancing guidelines in public places.

For breastfeeding women, they will have good immunity, but they won't know whether their babies do, so keeping up good physical distancing for their babies will still be important. And for everyone, an abundance of caution is a good idea until more people can be vaccinated and we are closer to reaching herd immunity.