A driver has been charged after allegedly fleeing the scene of a horror crash that claimed the lives of a woman and an unborn child, and left three others with serious injuries.

A Commodore sedan was driving on Newcastle Rd at North Lambton, a suburb of Newcastle in NSW, when it collided with a Hyundai sedan about 2.40am on Saturday.

A 28-year-old pregnant woman was driving the Hyundai and was seriously injured in the crash.

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She was rushed to Newcastle’s John Hunter Hospital, where doctors discovered she had lost her unborn baby.

The woman remains in hospital in a serious condition.

Her passenger in the Hyundai, a 55-year-old woman, was critically injured in the crash and died at the scene.

The driver and front-seat passenger of the Commodore allegedly fled the scene before police arrived.

He allegedly left two teenage girls, aged 15 and 17, seriously injured in the back seat of the Commodore.

Paramedics treated the girls at the scene before they were taken to John Hunter Hospital, where they remain in serious conditions.

After a police investigation, a 19-year-old man was arrested at a home in Mayfield on Tuesday afternoon.

He was charged with seven offences, including aggravated dangerous driving occasioning death, escaping pursuit and aggravated dangerous driving occasioning grievous bodily harm.

The man, from Wallsend, has been refused bail to appear before Parramatta Local Court on Wednesday.