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Separating conjoined twins

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Nearly twenty years ago, a court was faced with an agonising decision: whether the proposed separation of conjoined twins was lawful. A court decision was necessary; the parents opposed the separation because the operation would lead to the immediate death of one of their twins. This dilemma could re-emerge at any moment, so the decision merits study.

The case, Re A, concerned Jodie and Mary, born to devout Catholic parents. The girls each had their own brain, heart, lungs and vital organs; and each had 4 limbs. But the court was told that Mary’s cardio-respiratory system was insufficient to support life; she remained alive only because of their connected circulations. Jodie’s aorta supplied that of her sister; and their inferior cavae were distally united into a common channel. If Mary had been born as an independent baby, she would not have lived after cessation of placental circulation.

Without separation, the surgeons predicted that Mary would die within three to six months, followed within hours by her sister, who would exsanguinate into her dead sister’s circulation. Surgical separation in the neonatal period was feasible, and Jodie would be able to live a relatively normal life, but Mary would die within minutes of the division of the aortic connection. Their parents opposed the operation, believing their children’s fate should be left to God; and that terminating Mary’s life was wrong.

The legal ‘formula’ for murder in England requires an intention to kill (as well as an act that causes death) to be established. The Court in Re A recognised that each twin was a separate person for the purposes of homicide and that both girls had to be accorded equal rights to life, but considered Mary’s death to be justified as ‘the lesser of two evils’, declaring separation lawful. Nonetheless, the court conceded that the surgeons would by performing the operation ‘intend to kill’ Mary since her death would be virtually certain once her aorta was clamped. Although one of the reasons for the court’s decision was that the surgeons could rely on a defence of necessity (to save Jodie’s life), subsequent legal argument suggests that this defence may no longer be available.

Courts have held that the greater the scope for genuine doubt as to where a child’s best interests lie, the greater the expectation that the difficult decision will be taken by her parents.

Academic lawyers have suggested that seeking to justify giving priority to the welfare of one or other twin was an exercise too finely balanced for clinicians or judges to arrive at a conclusion with certainty. Put bluntly, it remains uncertain that either twin could mount a strong case that she should thrive at the expense of her sister. In these circumstances, the justification to usurp the parents settled decision to refuse surgery evaporates. At the same time, sociological evidence hints at conjoined twins’ profound disinclination to be separated. Plainly this evidence requires close scrutiny.

Taken together, considerable doubt is cast upon the proposition that the judgement in Re A can be relied upon by contemporary surgeons, faced with the prospect of needing to sacrifice the life of one twin for the benefit of another. It is arguable that if this sacrifice was made in 2019, the surgeons would need to convince a jury either that the elements of murder were not made out; or alternatively, that a defence against that charge was both available and applicable.

By extension, if the idea that enduring conjoinity was valued by and valuable to conjoined twins withstood critical analysis, courts might view any separation, whether or not imminent death of one twin was anticipated, with sufficient anxiety to defer a decision to separate until the children had capacity to make the choice for themselves.

Robert Wheeler
Department of clinical law, January 2019