The Siamese twins, known to the British public as Mary and Jodie, were joined at the pelvis with a fused spine. Although operations to separate other infants joined in such a manner have been relatively straightforward, doctors knew from before the girls’ birth that both babies could not survive.
Mary, the smaller and weaker twin, was fatally compromised. Her lungs and heart were not properly formed and her brain was primitive, although capable of sustaining life. If the operation had not taken place, both babies would have died. But the parents, devout Catholics, were not prepared to agree to the ending of Mary’s life. The case went to the high court which ordered that the separation should go ahead.