The vaccines are deemed safe and effective for pregnant women, and the Centers for Disease Control and Prevention (CDC) has been urging expectants mothers to receive the shots.
However, some providers have been refusing to give women the jabs when they arrive at the clinic and reveal they are carrying a child.
State officials this is a problem because pregnant women are more likely to suffer severe symptoms and even death from the virus, and failing to get vaccinated could leave them exposed to infection.
Some pregnant women report being turned away from vaccine clinics in Mississippi. They are among the least vaccinated group in America, with only 25% having received the shots. Pictured: A pregnant woman in Provo, Utah, receives a COVID-19 vaccine shot
'Some of the patients had reported to us that they had gone to be vaccinated, and were turned away because they were pregnant,' Dr Michelle Owens, a maternal-fetal medicine specialist at the University of Mississippi Medical Center (UMMC), told ABC News.
Some of these pregnant women have ended up hospitalized, where they are notifying doctors the reason they are unvaccinated.
One expert told ABC that some physicians may not be comfortable with giving drugs to pregnant people, even a vaccine.
'People are kind of adverse to pregnant patients when they come in. They're hesitant to give pregnant patients medications, and certainly, vaccinations kind of fall into that,' said Dr Marty Tucker, chair of obstetrics and gynecology at UMMC.