Police are still pursuing groundbreaking charges against a Wellington man following a crash which led to the death of his wife's unborn child.

The man's lawyer says the charge is uncalled for and should be dropped.

Ethiopia-born Bililigne Yohannes Gebretsadik, 40, has been charged with careless driving causing death after a two-car collision in the suburb of Newtown in June last year.

His wife and passenger Sebele Hailu Cherie, 40, later lost her baby - due in about nine weeks - following an emergency caesarean section in Wellington Hospital.

Gebretsadik's lawyer John Miller, in Wellington District Court on Wednesday, said his client was not guilty of careless driving causing death, or of two charges of careless driving causing injury to his wife and the other driver.

It is believed to be the first time in New Zealand history the killing of an unborn child has been the subject of the Land Transport Act rather than the Crimes Act.

Mr Miller said it was unnecessary and "extremely distressing" to put the couple through a case which would involve complex legal argument.

His wife did not want the charges laid.

He told the court Gebretsadik had been "punished more than other people can imagine", Fairfax Media reports.

Detective Inspector Paul Basham has said the investigation had been the subject of an independent legal review and police had not laid the charges lightly.

The case will go to a status hearing on February 28.