A Church of England curate has won the right to a judicial review into a case where a foetus with a cleft palate was aborted late in pregnancy.
Miss Jepson asked police to investigate the abortion
Joanna Jepson, herself born with facial deformities, believes that the operation breaches abortion law.
The High Court gave her permission on Monday to challenge in court the refusal of the police to prosecute.
She claims that a cleft palate is not a "serious handicap", which would allow the termination under the Abortion Act.
Neither the mother's identity, nor the date of the operation can be revealed, for legal reasons.
The operation was carried out after the 24th week of pregnancy, which would normally be illegal.
However, the law states that in cases where a severe disability is detected in the foetus, the mother has the option to terminate well beyond this date.
What constitutes a "severe abnormality" is not fully defined under the Act, and doctors can apply a degree of discretion when taking the mother's wishes into consideration.
However, when Miss Jepson, who says she is not an active anti-abortion campaigner, learned of the case, she made a complaint to West Mercia Police, asking them to investigate.
In papers submitted to the High Court, the force says it took the advice of a senior member of the Royal College of Obstetricians and Gynaecologists before making the decision not to take the matter further.
Miss Jepson, from St Michael's Church, Chester, then applied for judicial review, which was turned down at the High Court.
After Monday's ruling, she said: "Each step in this process
has been taken with trepidation.
"I have been encouraged by the public's support. I hope that we shall succeed at trial and recognise again the value and dignity of our common humanity, disabled or able-bodied, no matter what we look like."
"If we lost today it would undermine that move towards a less discriminatory society."
She believes that the decision to terminate on the grounds of a cleft palate amounts to "eugenics".
"This case is saying enough is enough.
"This law needs to be tightened, it isn't right that babies lose their lives for trivial reasons," she told the BBC.
What is it?
The argument centres over the acceptance by the doctors concerned that a cleft lip and palate constituted a "severe abnormality".
Clefts are detectable in the womb
A cleft palate happens when, during normal development, there is a failure of the body to fuse together cells making up the structures of the palate, lips and face.
Until recently, doctors did not have the ability to detect this problem in the foetus.
The degree of disability varies widely from case to case. Sometimes the cleft can go all the way up the face, sometimes there is far less malformation when the child is born.
A baby with cleft lip and palate faces problems early on, the most obvious being difficulties feeding, which may require the insertion of metal plates into the mouth.
However, operations are carried out to correct the cleft at a relatively young age - three months for lips, and 18 months for palate.
Further operations may be required if the facial bones continue not to grow properly, and treatment may continue until the child is in his or her 20s.
Ann Furedi, from the British Pregnancy Advisory Service, said she had been told that the severity of cleft palate varied widely, and in some cases the deformity could be life-threatening.
She said: "In this case we just don't know - we have to trust the doctors involved.
"I think it is absolutely bizarre that the Reverend feels - knowing absolutely nothing about individual circumstances of this woman, that she can go on to take legal action around it."