Men who lie to sexual partners about being infertile should not be found guilty of rape, judges have ruled.
The issue was considered because of an appeal by 55-year-old Jason Lawrance.
Last July he was found guilty of raping a woman twice - despite her consenting to sex - because he had lied about having had a vasectomy.
However, Court of Appeal judges said these convictions were unsafe and have quashed them. Lawrance has other rape convictions and remains in prison.
The woman deceived by him took emergency contraception but became pregnant, then had an abortion.
Despite this, the judges said Lawrance's "lie about his fertility was not capable in law of negating consent".
Lawrance is serving life sentences for his other rapes and his legal team did not appeal against any of his other convictions.
His solicitor, Shaun Draycott, said: "We are delighted by this judgment. There was real concern that the upholding of the convictions recorded at Nottingham Crown Court [last July] would have had the potential to criminalise large sections of an otherwise law-abiding population, both male and female.
"The ruling provides clarity on the important issue of whether one person's consent to a sexual act can be negated by another person's dishonesty."
Who is Jason Lawrance?
He was given a life sentence in 2016 for raping five women, attempting to rape one woman, and sexually assaulting another.
The assaults took place between June 2011 and November 2014 in Derbyshire, Leicestershire, Lincolnshire, Northamptonshire and Cambridgeshire.
He met the women through online dating site Match.com - which was also how he met his wife - and Dating Direct.
Lawrance, originally from Leicestershire, went on trial again last July accused of raping and sexually assaulting six more women. One of these was the woman he deceived about having had a vasectomy.
He was convicted of five charges of rape, one charge of sexual assault and a further charge of assault by penetration. He was found not guilty of two charges of rape.
How did Lawrance lie about his fertility?
Lawrance and the woman were texting each other before they met and he told her he had undergone "the snip" in a discussion about contraception.
Giving evidence in a trial last year, the woman said Lawrance also made the same claim verbally before they slept together.
They had sex twice and Lawrance left in the middle of the night. He later texted her saying: "I have a confession. I'm still fertile. Sorry xxx"
Clive Stockwell QC, prosecuting, asked the woman: "Would you have had sexual intercourse with him if he had not had a vasectomy?"
The woman replied: "Absolutely not; unless he had other protection."
She also told the court: "I was absolutely gobsmacked that anybody could do such a thing."
Lawrance's text messages were used as evidence he had deceived the woman, and that he knew the woman would not have consented to sex without contraception.
Why was he prosecuted for the deceit?
The Sexual Offences Act 2003 says a person commits rape if the other person "does not consent to the penetration" or they "do not reasonably believe" the person consents.
Section 74 of the Act specifies that a person consents if he or she "agrees by choice, and has the freedom and capacity to make that choice".
The prosecution's case was that the woman's consent was vitiated by Lawrance's deception.
Clive Stockwell QC, prosecuting Lawrance, told jurors that because he deceived the woman, this had "robbed her of her freedom of choice".
"Her consent was obtained by a deception," he said in his opening. "That, we submit, is not true consent."
Lawrance was charged with two counts of rape because he had sex with the woman twice.
Defence barrister David Emanuel QC said classing the deceit as rape was "taking it too far".
However, the jury decided it was rape and found Lawrance guilty of those two charges.
What did the Court of Appeal judges say?
The appeal was heard by the Lord Chief Justice for England and Wales, Lord Burnett of Maldon, sitting with Mrs Justice Cutts and Mrs Justice Tipples.
Their judgment said: "In terms of section 74 of the 2003 Act, the complainant [the woman] was not deprived by the appellant's [Lawrance's] lie of the freedom to choose whether to have the sexual intercourse which occurred."
The judges looked at similar cases involving deception, including Julian Assange's extradition case, where a judgment said sex without a condom would be a sexual offence in the UK if the other partner had only agreed on the condition a condom was used.
They also considered a case known as R(F), which involved a woman who consented to sex with her husband on the condition he withdrew before ejaculating.
However, the Court of Appeal judges said Lawrance's case was different from these cases.
The judgment said: "Unlike the woman in Assange, or in R(F), the complainant agreed to sexual intercourse with the appellant without imposing any physical restrictions.
"She agreed both to penetration of her vagina and to ejaculation without the protection of a condom."
The woman was, instead, "deceived about the nature or quality of the ejaculate", the judges said.
"The deception was one which related not to the physical performance of the sexual act but to risks or consequences associated with it."