Marco Paul Silvestri was driving a Mercedes Benz van with drugs in his system when he collided with an oncoming Honda sedan in September last year as he tried to overtake another car while crossing the Mullet Creek bridge at Dapto.

The crash seriously injured expectant mother Jacqueline Sparks and her two brothers, Jonathan and Timothy, all of whom were in the Honda.

Ms Sparks suffered a ruptured uterus in the crash and had to have emergency surgery to remove Mia from her womb.

The child was immediately intubated but showed no signs of life.

Silvestri was charged with three counts of dangerous driving causing grievous bodily harm, in line with current NSW laws that don't allow for a direct charge to be laid over the death of a foetus.

Ms Sparks penned a poignant letter to the court outlining her grief over her daughter's death, and her heartbreak at learning she would never be able to have children in the future because of her injuries.

"My womb had catastrophically ruptured upon impact...the surgeons had to remove all the surrounding organs to clear out the remains of my womb and my body was stiched back up from pelvis to chest," she said.

"I have lost my daughter, my womanhood and my chance to ever become a mother naturally."

In court on Wednesday, presiding judge Paul Conlon said Ms Sparks' pain at losing her daughter was palpable, and he considered the injuries caused to her by Silvestri's actions placed his culpability at the highest end of the range of objective seriousness.

"I'm satisfied he abandoned all responsibility to other road users," Judge Conlon said in refering to Silvestri's decision to deliberately move his car to the wrong side of the road and cause the collision.

He rejected an explanation by Silvestri that he'd had a "brain fart" moment and believed both lanes were southbound, noting Silvestri lived nearby in Kanahooka, and would have travelled that road regularly. 

Judge Conlon set a non-parole period of six years.