Toddler Tevye Kirton's beaming grin was even visible from the womb. At just 26 weeks old, the youngster gave his parents a glowing smile via ultrasound.

The pictures were captured by modern equipment, known as the 4-Dimensional scanner.

Tevye's parents, Theresa and Trevor Kirton, from Southwater, Horsham, were almost in tears when they glimpsed the first clear emotions on his tiny face.

Mrs Kirton, 30, said: "When the professor was scanning me we started to call the baby's name and it was amazing - he started to smile back at us. It was amazing just seeing him there.

"We were almost in tears."

Mr Kirton, 43, an IT consultant, said: "It was an incredibly emotional moment. He knew we were there and was smiling for us.

"We had spent a long time playing him classical music and talking to him in the womb but to see his response was astonishing.

"He also appeared to be concentrating at one point and was pulling exactly the same face as I do when I am thinking hard."

The couple decided to have the scan, now employed at some clinics and teaching hospitals, after an NHS scan ultrasound indicated there could be a problem with Mrs Kirton's womb, which would stop her from having a natural delivery.

Thankfully, the more advanced scan showed everything was fine.

Tevye, now 21 months, likes to watch himself as he was in the womb from a video made of the scan.

Mrs Kirton said: "He asked 'Who is that?' so we told him. He now knows it's him.

"I don't know what he'll say when he's older but we'll definitely show him the video."

The images of babies like Tevye, published for the first time this week, suggest unborn babies can smile, blink and cry weeks before they leave the womb.

Until now it was believed infants only learnt to smile by copying their parents.

Experts are debating whether Tevye's apparent grin reflects an emotional response or is an instinctive physical reaction.

The new ultrasound technique, pioneered by leading obstetrician Professor Stuart Campbell, of the privately-run Create Health Clinic in London, also clearly shows limb movements at eight weeks.

The foetus can be seen leaping, turning and "jumping" at 11 to 12 weeks, making intricate finger movements at 15 weeks and yawning at 20 weeks.

The discovery adds a new dimension to the debate about the morality of abortion.

Anti-abortion campaigners said the images proved foetuses could feel pain and show emotion at 24 weeks of a pregnancy, when termination is still legal.

Paul Denon, of the Society for the Protection of Unborn Children, said: "Babies are babies right from the start and are human beings.

"We are pleased this development will show people the humanity of the unborn child."