The jury in the case of a motorist accused of causing the death of a heavily-pregnant mother and her unborn child has retired to consider its verdicts.

Rebecca Evans, 27, died at the scene of a collision on the M4 near Port Talbot, South Wales, caused after Craig Scott, 51, drove his BMW into the back of the stationary Peugeot she was in with her partner Alex Evans and their young son.

Ms Evans' unborn daughter, Cari, also died - while her two-year-old son Cian had to be airlifted to hospital after suffering a skull fracture and broken legs.

Scott, of Heath, Cardiff, who previously admitted causing Ms Evans' death by careless driving - but denies the more serious charges of causing her death and Cian's serious injury by dangerous driving, went on trial at Swansea Crown Court on Monday.

On Thursday, during his summing up, Judge Keith Thomas told jurors that they "must put emotions to one side" during their deliberations and be "rational and objective" in their assessment of the evidence.

"Nobody hearing about such events could fail to be moved by the tragedy," he said.

The court has heard Scott, a plant manager at the Baglan Bay power station, was driving to work on November 29 2016 and had made two handsfree mobile phone calls before the collision at around 8.13am.

The second of those calls was to his boss and finished between 14 to 34 seconds before the impact.

Catherine Richards, for the prosecution, said Scott was "quite simply avoidably and dangerously distracted" and did not notice Ms Evans' car had come to a stop in queuing traffic until it was too late.

The court has heard there was no evidence of Scott braking and that he was driving at around 70mph.

Giving evidence, Scott said of the moments before the collision: "I was driving along and there was something that attracted my attention on the bridge [above the motorway] and I looked away. I glanced away and there was something that attracted my attention on the left of me as well, so I glanced at that.

"Obviously that's distracted my attention from the road ahead and I believe that's caused the accident."

Scott said he did not know what either of the things that attracted his attention had been, but that he was not distracted by the phone calls.

In his closing speech, Craig Harris, for Scott, urged jurors to "put themselves in that position" and to conclude that this was careless, not dangerous, driving.

The trial continues.