## Facts

- The case concerned conjoined twins, referred to as Mary and Jodie, who were joined at the lower abdomen.
- Mary suffered severe brain abnormalities, had no lungs, and was entirely dependent on Jodie’s circulatory system.
- Medical opinion determined that without surgical intervention, both twins would die; separating them was the sole option for Jodie’s survival, but it would inevitably result in Mary’s death.
- The medical team sought a court declaration that such a procedure would be lawful.
- The twins’ parents opposed the separation on religious and moral grounds, leading the matter to the Court of Appeal.

## Issues

1. Whether the proposed surgical separation of the twins, which would cause the certain death of Mary in order to save Jodie, could be considered lawful.
2. Whether the surgeons’ intentions and the act-versus-omission distinction in medical law affected the lawfulness of the operation.
3. Whether the defense of necessity could apply in a situation where one life is taken to save another.

## Decision

- The Court of Appeal permitted the separation surgery to proceed, finding it lawful.
- The judges held that the primary intention was to save Jodie, not to kill Mary, even though Mary’s death was a foreseen consequence.
- The defense of necessity was considered applicable; the court found that the conditions for necessity were satisfied because the operation was essential to avoid the irreparable evil of both children dying.
- The appeal was dismissed; the operation went ahead, resulting in Jodie’s survival.

## Legal Principles

- Distinction between direct intention (aimed-for outcome) and foreseen but unintended consequences in criminal law.
- The act versus omission principle from Airedale NHS Trust v Bland [1993] AC 789 did not apply, as the case involved a positive surgical act, not withdrawal of treatment.
- The defense of necessity requires (i) the act to avoid inevitable and irreparable evil, (ii) steps taken to be no more than reasonably necessary, and (iii) the harm caused to be proportionate to the harm avoided.
- The court reaffirmed that in medical cases involving children, the welfare of the children is the primary concern.

## Conclusion

The Court of Appeal in Re A (Conjoined Twins) allowed the surgical separation to proceed, holding the operation lawful under the principle of necessity and establishing key guidance on intention and proportionality in complex medical cases resulting in the death of one to save another.


Re A (Conjoined Twins) [2000] 4 All ER 961