St John Ambulance officers began CPR on the 27-year-old woman in the town of Meekatharra, 775 kilometres north-east of Perth, and took her to Meekatharra Hospital on Monday night.

A Royal Flying Doctor Service spokeswoman told news.com.au the woman was 31 weeks pregnant.

News.com.au understands a call was received at 8:15pm Monday night with reports a woman in her 20s was “having a fit” after “something bit her”.

When emergency services attended a member of the public was already performing CPR on the woman.

AAP reports an RFDS doctor helped staff at the hospital but the woman went into cardiac arrest and died.

It is not yet known which type of snake killed the woman.

Her body is being transported to Perth where a post-mortem examination will determine the exact cause of death.