The high court will today decide whether girls under the age of 16 should be allowed to terminate a pregnancy without their parents' consent.

Sue Axon, 52, a single mother of five from Manchester, took the government to court last year in a judicial review challenging guidance giving teenagers the right to contraception and abortions without their parents' knowledge.

Ms Axon says parents should have the automatic right to know when their child is seeking a termination except where there is evidence they might be abusive.

During the hearing in November, lawyers for the health secretary, Patricia Hewitt, argued that guidance guaranteeing confidentiality to young people, except where they are considered to be at risk of abuse, was crucial. Without it, attempts to reduce the number of teenage pregnancies and tackle sexually transmitted infections would be compromised because teenagers would be put off seeking help.

Ms Axon told the Guardian that her argument centred on the fact that children could not get other serious medical treatment without their parents' knowledge. "A dentist can't take a tooth out without parents' knowledge, a schoolteacher can't give a plaster, you can't get a tongue pierced but you can get an abortion. How crazy is that?" she said.

After reading about Melissa Smith, a 14-year-old from Wakefield who had an abortion arranged by a school outreach worker without her mother's knowledge in 2004, Ms Axon investigated the guidance in her daughters' school and found the same could happen there. She contacted a solicitor and applied for legal aid.

Ms Axon said that an abortion she had at the age of 30, after which she suffered medical complications and depression, motivated her to take the case so far. "I wouldn't want my children to go through that without support from me," she said.

It emerged during the court case in November that her daughter, then 15, was pregnant.

"I set out to protect my own daughters. You can't change human nature and, of course, teenagers will still have sex, but they shouldn't be allowed radical medical treatment without my knowing," she said.

Ms Axon said current guidance provided a cover for abuse. "As it stands, this guidance just protects abusive parents and paedophiles. They can continue to abuse and no one finds out," she said.

But the government and campaigners argue thatconfidentiality is crucial. Susie Daniel, London chief executive for Brook, which offers confidential advice to teenagers, said: "We would have an uphill battle to persuade young people that we are still a safe place to get advice if the law changes. Confidentiality is key to working with young people."

A spokeswoman for the Department of Health said it stood by its guidance and declined to comment further before the judgment.

FAQ: The law

Can under-16s get contraception and abortions without their parents' knowledge?

Yes. Department of Health guidance makes clear that the young person's right to treatment overrides their parents' right to know. The exception is when an advice worker, nurse or doctor suspects the child is being abused, in which case they are compelled to tell the police.

How long has confidentiality been in place?

A case brought by Victoria Gillick in the early 1980s led to the legal establishment of the right to confidentiality in accessing contraception for under-16s. There are provisos: the practitioner must be convinced that the teenager understands their decision and that attempts were made to persuade them to tell their parents. The DoH guidance issued in 2004, which Sue Axon is challenging, says the practitioner should also try to get the young person to tell another responsible adult if not their parent.

If Ms Axon wins, what will change?

Ms Axon wants parents to be told automatically when their child is requesting an abortion, except where professionals are convinced that the child's safety would be compromised by abusive parents. It would override the 2004 guidance.

'I won't ever tell my mum about it'

Case study: Stephanie, 14, Brixton

I was pregnant last year, I had an abortion. When I found out I started asking my mum questions to see how she would react if I told her and she got suspicious. She just said that she would chuck me out of the house if I did that. I didn't say anything after that.

I kind of wanted to tell her. Then if I needed someone to talk to I could talk to her. But I don't think it's my mum's business to know about my sex life.

I won't ever tell my mum about it now. She would get more mad at me now for not telling her at the time.

I wouldn't have come to a clinic if they contacted my parents. That's the most important thing about getting that support. When I came to the clinic they spoke to me and tried to find out whether I was being pressured by my boyfriend.

If they wanted to tell my mum I would still have sex, but I wouldn't go to a doctor. I would try to get a friend to get contraception for me. I don't know what I would have done when I was pregnant.