Following the allegedly unprovoked attack, the woman - who is 30-weeks pregnant - fell to the ground clutching her stomach where she was helped by a passerby.
A 28-year-old woman has been arrested by an off-duty police officer after allegedly attacking a heavily pregnant woman as she walked down a street in Sydney's Surry Hills, NSW police said.
According to police, the victim - who is 30-weeks pregnant - was walking to work just before 9 am on Tuesday when another woman suddenly emerged from an alcove and allegedly began hitting her in the head.
The 26-year-old victim also allegedly had her hair pulled before she was rammed into a power pole.
NSW Police Force allege the attack was unprovoked.
"It was just a totally unprovoked, unwarranted, unnecessary attack," Detective Chief Inspector Adam Johnson told reporters on Tuesday.
Following the incident, the victim fell to the roadside clutching her stomach and a passerby intervened, helping her away. The victim was taken to hospital for observation.
Meanwhile, an off-duty probationary police officer apprehended the alleged attacker and took her to Surry Hills Police station where she was charged with assault occasioning actual bodily harm.
Inspector Johnson praised the passerby and the off-duty officer for their quick action.
“The civilian did not hesitate to leap to the rescue of the pregnant woman and we commend his bravery,” he said.
“We would also like to praise the swift response of the probationary constable who saved the woman from further harm."
The 28-year-old, from Mount Druitt in Sydney's west, appeared in Central Local Court on Tuesday afternoon and was refused bail.