The incident took place at the intersection of Bruce Roderick and Offenhauser Drives in East Tamaki, Auckland, on May 19, 2023.
Police said the 24-year-old man could not be named for legal reasons. He was sentenced on Wednesday to two years and four months' imprisonment for manslaughter, dangerous driving and driving while disqualified.
He was also disqualified from driving for another 12 months.
"The events of that night were a tragedy for everyone concerned," Detective Senior Sergeant Dean Batey said.
The woman was a spectator, and was seriously injured and had to undergo emergency surgery.
"Her young baby sustained such catastrophic injuries that she barely even stood a chance at life and did not survive the day," Batey said.
The driver was 22 at the time.
Police said they would "continue to carry out disruptive and enforcement activities in response to anti-social behaviour on our roads".
"A lot of this behaviour ends up as merely a momentary rush of glory on social media or amongst peers," Batey said.
"The reality is that the driving taking place on public roads is putting participants, spectators and innocent members of the public at real risk.
"I put this question to those taking part: Is a life really worth it?"
