Vaccination is likely the best way to prevent COVID-19 in pregnancy, when risks for severe illness and death from the virus are higher than usual. 

The American College of Obstetricians and Gynecologists says COVID-19 vaccinations should not be withheld from pregnant women, and that women should discuss individual risks and benefits with their health care providers. 

The U.S. government's emergency authorization for the Pfizer and Moderna vaccines being rolled out for priority groups doesn't list pregnancy as a reason to withhold the shots.

But the OB-GYN group says women should consult their doctors, since COVID-19 vaccines have not yet been tested in pregnant women. Evidence about safety and effectiveness is reassuring from studies that inadvertently included some women who didn't know they were pregnant when they enrolled.

More answers are expected from upcoming research, including a study by Pfizer and German partner BioNTech expected to start early this year that will include pregnant women.

Experts say there's no reason to think the two authorized vaccines would harm fetuses. They might even protect them from developing COVID-19, although that hasn't yet been proven, said Dr. Denise Jamieson, chair of gynecology and obstetrics at Emory University School of Medicine.

That thinking comes in part from experience with vaccines for influenza and whooping cough, which are approved for use in pregnancy and protect newborns and their mothers from developing those diseases.