When the Grammy award winning songwriter, Olivia Nervo, agreed to start a family with her partner she believed she was in “a monogamous, committed relationship leading to a future”, and had never heard of reproductive coercion.

Her world came crashing down when she was six months pregnant and she found out that her partner was in a relationship with another woman who was also pregnant, and with whom he already had a child.

It was a discovery that led her to learn about reproductive coercion, a form of controlling behaviour in which someone interferes with an individual’s ability to make decisions about their own body. The Labour MP, Natalie Fleet, led a debate in parliament on the issue last month in which she said it was “so important – in the public interest, even – that the story of Olivia Nervo is heard”.

The court declined to make any finding as to whether there had been reproductive coercion in Nervo’s case, with Fleet describing the doctrine as something the legal system in England and Wales “still struggles to recognise”.

Nervo, one half of the DJ and songwriting duo of the same name with her twin sister Miriam, fought a lengthy, expensive and ultimately dispiriting court battle in London against her former partner, the wealthy New Zealand businessman, Matthew Pringle, sometimes known as the “honey king” because of his ownership of businesses including Manuka Honey.

She said: “If you have sex with someone and you don’t disclose the fact that you have an STD (sexually transmitted disease), that’s assault [if you are infected they can be charged with grievous bodily harm] and that’s criminally chargeable. And if you remove a condom covertly that’s considered rape. But if you deceive someone into having a child, or just even having sex, you just fall between the cracks.

“I can’t get over it, I don’t think I’ll ever get over it. And I just feel like reproductive coercion needs to be considered properly within family courts, at the very least. I would love it to be a standalone offence, but I understand that’s a big wish.”

A 2022 poll of 1,000 women aged 18 to 44 found 50% believed they had experienced reproductive coercion of some form, including pressure around pregnancy, abortion, sex and contraception.

Reproductive coercion is recognised in England and Wales as a form of coercive control under the Serious Crime Act. But Prof Sonja Ayeb-Karlsson, professor of intersectional justice at UCL, said that coercive control has itself “taken almost 10 years to understand” and, without its own standalone offence, reproductive coercion gets overlooked in the criminal justice system and criminal courts. She added: “I have tons of women who contact me who say: ‘This happened to me but I never spoke about it because I was so ashamed. Or, I couldn’t really put my finger on what it was or if it was wrong’.”

Olivia Nervo and Matthew Pringle. Photograph: Olivia Nervo

Nervo and Pringle met in 2016, and began trying for a child in 2018. “We named our child before she was born, we sort of had an idea of where we would live and settle,” said Nervo.

In February 2019 while six months pregnant, Nervo said she encountered a woman at Pringle’s Auckland office who told her: “He [Pringle] is meant to be in hospital, he’s having a baby this morning with my sister.”

When Nervo and Pringle’s child was born, he tried to tie financial support to confidentiality. Nervo wanted to publicise what had happened to her but in 2020, Pringle accused her of defamation and breaching his and their infant daughter’s privacy rights.

A court of appeal judgment from last month said Pringle proposed a £20m trust fund for their daughter and providing a £3m property, but financial negotiations stalled because “the parties remained in dispute as to the mother’s use of social media and in relation to the publication of an interview she had given”.

In 2022, more than three years after their daughter was born and while concerned about impending publication of another interview about their relationship and child, Pringle issued legal proceedings, applying for a parental responsibility order.

The court proceedings provided partial vindication to Nervo. In a high court judgment last year, Nicholas Allen KC determined that, based on the timing of the legal action, Pringle was motivated to bring family court proceedings partly “to protect his privacy and safeguard his reputation” through the strict reporting restrictions, including anonymity, which are normal in family proceedings to protect children. The judge also found that another motivation was a desire to establish a relationship with his daughter.

Pringle admitted domestic abuse of an emotional nature, including dishonest conduct before the birth of their daughter. Allen said: “The father’s behaviour towards the mother was reprehensible and I have no doubt it comes under the heading of domestic abuse. It appears to me that some of it probably can be characterised as controlling behaviour, as by his deception he engineered the mother to behave in a way she would not have done otherwise.”

However, another judge refused permission for a fact-finding trial to hear allegations of reproductive coercion, deeming it unnecessary to determine welfare issues.

Nervo said of Pringle’s admissions of domestic abuse: “He [Pringle] wouldn’t say it was reproductive coercion. The courts didn’t think it was necessary to name it, which I still disagree with. I think labels protect us in many ways. They just sort of made it broad as emotional abuse in nature.”

Her disappointment was compounded when the court of appeal overturned Allen’s ruling that Pringle, who withdrew his legal claims at the 11th hour, should pay 75% of Nervo’s costs of more than £500,000.

Delivering the court’s judgment, Lady Justice King, said that while Pringle’s behaviour was “shameful and deceitful”, Allen should have “factored in the mother’s late application for a finding of fact hearing which derailed the consensual progress of the case”. Lord Justice Males, sitting alongside King, described it as “a great pity” that when Nervo instructed a new legal team in September 2023 she introduced allegations including reproductive coercion which were “guaranteed to send the temperature of the litigation soaring and to increase the costs substantially”.

Nervo said: “I was deemed as just as unreasonable as him [Pringle]. To this day I haven’t even read that judgment in full because I’m so traumatised by it, I just can’t believe that’s where we ended up.

“You’re so vulnerable. You’re left open, and courts don’t want to see it, courts don’t want to name it. Courts punish you for wanting to name it. It’s just a really sad, sorry, state of affairs.”

As the court of appeal proceedings were in open court it meant they were no longer subject to reporting restrictions and Nervo could speak openly.

Since posting on social media, she says she has been contacted by hundreds of women with similar experiences.

Olivia Nervo, Labour MP Natalie Fleet and Miriam Nervo (L-R) Photograph: Olivia Nervo

Fleet told MPs: “If our courts are presented with clear evidence of coercive behaviour that has resulted in pregnancy, yet decline to recognise or name it, we are left with a gap not just in terminology, but in protection.

She added: “There are cases like Liv’s where the evidence is present, and yet it is still not being named. That must change. My ask of the government is for clearer recognition of reproductive coercion in the law … We need to ensure that patterns of behaviour are examined, not dismissed, and that individuals who raise legitimate concerns are not penalised for doing so.”

In response, the justice minister, Alex Davies-Jones, said that the current review of family courts would examine reproductive coercion.

Pringle declined to comment.