A ST ALBANS woman, pregnant with Siamese twin girls, is facing the stark choice that she will have to sacrifice one daughter in order to save the life of another.

Ms Tina May, 23, risks losing both babies unless she allows doctors to separate the pair, who share just one heart and one liver.

She said: "This is the most horrific choice for any parent. I will have to let one die so the other can live."

Ms May and her fiance Dennis Smith, 33, a St Albans bus driver, learned that they were expecting conjoined twins during a routine ultrasound scan at the QEII Hospital in Welwyn garden City in November last year.

They now face the grim prospect of allowing doctors to separate the girls named Natasha and Courtney, in the full knowledge that only one will be strong enough to survive the surgery.

Doctors plan to deliver the twins by Caearean section at 37 weeks. They will then be transferred to Great Ormond Street and kept alive for one month until strong enough to undergo the gruelling operation.

Although the life chances are slim for both girls, medical staff believe that Natasha as the dominant twin has the strongest chance of survival because she has a greater proportion of the heart muscle.

Conjoined twins are an extremely rare medical condition affecting less than one in every 100,000 births. They occur when a fertilised egg splits in two, but fails to complete the splitting process, meaning the identical twins grow together as one.