Two videos, uploaded on Facebook by the woman's husband Syamjith Syamalan, show the group of protesters angry at the couple for trying to pass through their procession. Mr Syamalan says the group blocked their car, hit the bonnet and the sides after arguing with the couple.
"There was a massive jam due to the UDF procession and we were stuck for a considerable time. We thought my wife would deliver her baby soon. I approached a police official standing nearby and he suggested that we follow the DGP's vehicle to get through the procession. But instead the protesters stopped our vehicle, threatened and abused us and damaged our car," Mr Syamalan told NDTV.
He later filed a police complaint.
The incident took place during a pro-UDF procession of the eve of the protest called by the UDF in Kerala against the rising prices of petrol, diesel and cooking gas. "We will be going to meet the doctor today after 6 pm, once the Hartal gets over. I cannot take any more risk," Mr Syamalan said.