The woman was part of a large group that says it was being harassed by police on Sunday, July 21.
Police have a different view.
"We have full confidence that our officers did act appropriately," Ocean City police spokesperson Lindsay O'Neal told CBS Baltimore.
O'Neal says the incident began with the group yelling, cursing and disrupting families at the beach. She says a lifeguard asked them to tone it down and that one person in the group threatened the lifeguard - followed by threats to police when they arrived.
O'Neal says the pregnant woman was assaulting officers prior to being taken down.
"Any person who assaults a police officer must be detained," she said.
Cell phone video of the confrontation begins with shouting, and Ocean City officers quietly standing by.
Then, according to the police version, 25-year-old Abdul Kargbo of Woodbridge begins cursing and yelling at officers, and begins walking away.
Soon officers take down other members of the group, including the pregnant woman.
Police say she will be charged with assault and resisting arrest, along with Kargbo, 24-year-old Musa Seisay and 21-year-old Saidu Kargbo
According to CBS Baltimore, members of the group would not go on camera but say the police account is totally false and they were racially profiled.
They are reportedly considering legal action against Ocean City police. The group also says it has more video of the incident.