Parents need to be vigilant but should be reassured these sorts of events are very rare

Great Ormond Street Hospital spokeswoman

Her parents had to endure an agonising 17-day ordeal before police found Alex in a cottage in the Cotswolds.

Visitors to the maternity unit at the Wordsley Hospital must also speak into a voice intercom and can be observed at all times by a camera sited directly above the door.

Ward F4, from where the baby was taken, is on the top floor of the modern four-storey maternity hospital.

It is where mothers and their new arrivals are taken shortly after giving birth in the delivery suite on the first floor.

Babies lie in clear plastic cots seated on small trolleys, at the side or end of their mothers' beds, and mothers are encouraged to wheel their babies with them at all times.

Alarm tags

Such measures are in place in maternity wards across the UK, with CCTV cameras and 24-hour security now commonplace.

Special alarmed name tagging systems were also brought in, although many hospitals decided not to introduce them because the tags could be removed without triggering the alarm.

However, because hospitals are open places with staff and visitors coming and going at all times of the day and night, enforcing security is very difficult.

Official NHS guidelines say: "It is vital that parents, visitors and staff are aware of the importance of security measures, to report any suspicious behaviour, to challenge unidentified people and never to leave infants unattended."

Vigilance needed

Despite the increased security, there have been a number of lapses.

Abbie Humphries was snatched from Nottingham's Queen's Medical Centre in 1994, while last year six-month-old Joshua Cahill was abducted from Cheltenham General Hospital.

The babies were eventually reunited with their parents.

A spokeswoman for Great Ormond Street Hospital in London said: "Parents do need to be vigilant but they should be reassured that these sort of events are very rare.

"It's a difficult balancing act but security is a top priority for hospitals and it is something they do take incredibly seriously."