An ambulance was called to the car park of the Domain Medical Clinic at about 2pm today to treat the woman and her male partner.

"A 19-year-old female, six months pregnant, had acid over her," an ambulance spokeswoman said.

"She had inhaled or ingested some of the acid.

"And a similar aged male partner had burns on his arms."

Paramedics said the woman's injuries were not believed to be life threatening.

Police were investigating the incident but it was not clear if the burns were caused by accident or in a dispute.