Doctors have been given the go-ahead by a judge to perform an abortion on a woman with severe learning disabilities.
A police investigation is underway after a GP discovered that the woman - who is in her 20s but has the mental age of a toddler - was 12 weeks pregnant.
At a hearing at the Court of Protection in London, where judges consider issues relating to people who lack the mental capacity to make decisions, Mr Justice Williams was told the woman may have been raped or been made pregnant by a man who also had learning disabilities and a lack of understanding.
DNA tests are being carried out to establish the identity of the father, but bosses at an NHS hospital trust asked the judge to allow doctors to perform a surgical termination.
A lawyer representing the trust said the woman, who lives in the north of England and cannot be identified, had lived with foster carers for most of her life.
Barrister Eloise Power said the woman's foster parents were Christians and churchgoers but believe an abortion is in the woman’s best interests - something medical specialists and council social workers involved all agreed with.
Mr Justice Williams said authorising the termination of a pregnancy was a matter of "great moment" and a "significant interference" in a woman's autonomy but he said the woman's best interests were the "lodestar" of his decision, and evidence showed that allowing the pregnancy to continue would harm her.
Evidence showed the pregnancy was already affecting the woman's mental health and causing her to behave in a "somewhat more aggressive fashion" and if it continued she would have to go for intrusive medical examinations and would not be able to care for a child.
The judge said medics could restrain the woman in order to administer a general anaesthetic if necessary.
He also said the names of the hospital and council involved could not be revealed in case they led to the woman’s identity being made public.
The decision comes just months after Mrs Justice Lieven ruled that termination was in the best interests of a woman who was 22 weeks pregnant in the same court.
That decision was overturned by Court of Appeal judges who decided the woman, who is in her 20s but has the mental age of a child aged between six and nine, should be allowed to give birth.