Despite frantic efforts by the emergency services and medics who treated the woman at a local hospital, the mum-to-be and her baby were both were pronounced dead.
The 33-year-old was seven months pregnant.
The accident happened on London Road, Whitley, Coventry, at 5.35pm on Friday. A 57-year-old male driver was voluntarily interviewed and continues to co-operate with officers.
PC Damian Gibson told the Coventry Telegraph that family liaison officers have been appointed to support the woman's family, and appealed for witnesses to the collision to come forward.
Hundreds of shocked local residents took to social media to pay their respects to the mum and her unborn baby.
One, Jaz Bagri wrote: 'So, so sad and heartbreaking to hear. My thoughts are with the family and I really do wish them the strength to get through this. Living day by day with tragedy and the loss of loved ones is truly difficult. RIP.'
Another, Paul T Kelly wrote: 'Speechless and shocked to see this – thoughts and love to them both. RIP X.'