done specific studies on pregnant women...
From the FDA website:
https://www.fda.gov/emergency-preparedness-and-response/coronavirus-disease-2019-covid-19/pfizer-biontech-covid-19-vaccine-frequently-asked-questions#:~:text=While%20there%20have%20been%20no,with%20their%20healthcare%20provider.
Q: Can pregnant or breastfeeding women receive Pfizer-BioNTech COVID-19 Vaccine?
A: While there have been no specific studies in these groups, there is no contraindication to receipt of the vaccine for pregnant or breastfeeding women. Pregnant or breastfeeding women should discuss potential benefits and risks of vaccination with their healthcare provider..