Anna Jones (not her real name) remembers the days after giving birth to her son James as the worst of her life. The 30-year-old mother developed a rare form of mental illness known as puerperal psychosis. She had terrifying delusions that she was being tortured in a concentration camp, and was admitted to a psychiatric ward.

"I knew I needed urgent help, and agreed to go because they reassured me that James would be with me," she says. "But when I got to the ward there was no cot in my room - they had lied."

She was kept in the general psychiatric unit without her baby son for two weeks, and was convinced that she would never see him again. She remembers the time vividly. "No one would tell me what was happening, I felt like they had taken James away as a punishment for being ill." Anna was later transferred to a specialist mother and baby unit (MBU) where she was reunited with her son and successfully treated for her illness.

This month, the National Institute for Clinical Excellence (Nice) will issue new guidelines for antenatal and postnatal mental health procedures, following a review ordered by the Department of Health.

Elaine Hanzak will be watching developments closely. Like Anna, she too developed a severe mental illness after having her baby, and began harming herself. The nearest MBU had been closed over the Christmas period, so she was admitted to the general psychiatric unit. Separated from her son, she was forced to stop breastfeeding, which she believes may have slowed down her recovery.

Ten years on and now a successful author, Elaine campaigns to improve mental health facilities and passionately believes that mother and baby should stay together. "I will always feel robbed of that time without Dominic and believe no woman should have to go through that kind of experience," she says.

Unfortunately, agencies working in the mental health arena say it is all too common. Research for the charity Mind revealed that 63% of women with postnatal illness had been admitted to hospital psychiatric wards. Three-quarters of mental health trusts in England didn't have, or have access to, mother and baby units.

Deborah Morgan-Graham from the postnatal charity PNI-UK, which provided the information for Mind's report, says the situation is appalling. "It is extremely cruel to separate a woman already in distress from her child, and quite frankly shouldn't be happening. Specialist perinatal services should be universally available."

With around eight "real" mother and baby units (as opposed to a room attached to a psychiatric ward) and no central funding, she says vast areas of England and Wales have no support. Puerperal psychosis is rare, and affects one or two women in a thousand. But she believes many mothers are simply not getting the treatment they deserve.

However, the tide may slowly be turning. The publication of the Confidential Enquiry into Maternal and Child Health (2004) put mental health issues in the spotlight. It revealed suicide as the leading cause of maternal deaths in the UK and concluded that many could have been prevented if underlying problems of mental health had been dealt with.

Such was the case of Daksha Emson. The 34-year-old psychiatrist, who had a history of bipolar disorder, killed herself and her three-month-old baby, Freya. An independent inquiry revealed many mistakes were made in her care and highlighted the fact that, had she lived in Hackney rather than Newham, she would have had access to a perinatal psychiatry service. The report concluded that the tragic deaths could have been avoided.

Her husband David hopes that lessons have been learned. He says: "As a psychiatrist, Daksha recognised the importance of specialist services. I believe that mothers with mental illness have needs above and beyond general psychiatry. Perinatal experts are a necessity not a luxury."

The government's mental health czar, Professor Louis Appleby, accepts there may have been problems in the past with postnatal care, but believes things are moving in the right direction. He says more money than ever is being directed into mental health, with the focus on early intervention and community-based treatment.

"I think we are often too critical and should try to look at the positive steps being made. Staff in this profession work very hard to deliver the best possible service," he says.