Firefighters rescued a pregnant woman and a man trapped in their bedroom by a blaze.

Three fire engines from Watford and Garston were called to Hagden Lane, Watford, by the East of England Ambulance Service at 2.18am today.

They found a young couple, one of whom was a woman 31 weeks pregnant, hanging out of the bedroom window of a terraced house.

Firefighters rescued the couple using a ladder and broke through the front door to tackle the blaze with breathing apparatus, a hose and a covering jet.

Both were taken to Watford General Hospital for treatment for smoke inhalation. Their injuries are not thought to be life-threatening.

Green Watch's Watch Commander Derek Macleod said the occupants were "panic stricken" but calmed down when firefighters arrived.

He believes the fire started in the kitchen of the home and rapidly took hold. An investigation into the cause began today.

He said by the time the couple had woken up, the house was already heavily smoke-logged.

Although the couple had three smoke alarms, the batteries had been removed from all three.

"It is so important that you have working smoke alarms.

"The fact that they did not have an early warning meant that they woke up to a fire that was far more developed than it would have been had they had a smoke alarm that worked."

Hertfordshire Fire and Rescue Service’s director of community protection and Chief Fire Officer, Darryl Keen, said: “The fire crews worked extremely quickly and professionally and there is no doubt that without the very fast response of both HFRS Fire Control and the responding crews the outcome could have been substantially worse.

“The property involved had smoke alarms fitted but none had batteries and so the residents were lucky to wake up. As a result Community Protection teams will be undertaking awareness activities in the area over the coming days.”