The Government is coming under pressure to justify why it imprisons pregnant women and their babies, after a report suggested that the practice can cause significant harm to infants and mothers without benefiting public safety.

Campaigners, MPs and midwives have called for urgent reform in the light of evidence suggesting babies may be suffering mental and physical disabilities as a result of being held in prisons and claims that pregnant women are being watched by male guards while giving birth.

Some 600 pregnant women are held in prisons in England and Wales every year, with at least 100 babies being born while their mother is serving a prison sentence. Unlike many countries, the UK does not make sentencing allowances for women who are pregnant in the criminal justice system.

Following assessments, some are allowed to keep their baby with them in prison after birth until they are 18 months old in a specialist Mother and Baby Unit. Others have their baby taken from them shortly after birth to be placed with a family member outside the prison or to enter the care system for fostering or adoption. Women tend to continue in standard prison cells as usual while pregnant, being taken out to scans and check-ups at nearby hospitals by prison guards and transferred to local maternity wards for the labour, before returning to prisons or Mother and Baby Units after birth.

The concerns are highlighted in a report published by Birth Companions, an organisation helping women who are pregnant inside the prison system, which raises concerns that many women and babies are being seriously failed by the criminal justice system. The report highlights growing research suggesting babies born in prisons are much more likely to develop ADHD, autism, mental health problems, have a lower birth weight and suffer attachment issues than other babies.

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Research has suggested this is partly caused by hormonal disruption caused in the womb due to acute distress experienced by pregnant women in prison. The issue is thought to be further compounded by restrictive and repetitive prison environments which mean babies do not experience new faces, sounds or sights during key developmental periods, causing them to suffer developmental delay.

There are also concerns pregnant women are not receiving adequate nutrition as they eat heavily processed, unhealthy food from prison canteens meaning they and the babies risk becoming seriously underweight during pregnancy and breast feeding. One woman said: “We are meant to be able to eat, we’re meant to be able to drink. We shouldn’t be dehydrated. The prisons may say ‘we are feeding them’ but I’ve still got my [medical] notes that say I was dehydrated and starving - that’s what the midwife was saying: ‘This girl is starving and dehydrated we’re keeping her in [hospital]’.”

One woman told The Independent spending limits in prison shops mean women have to chose between extra food or telephone credit, she said: “I had to decide, do I get extra food for me and my baby or do I phone my mum so I can talk to her about how the baby is doing and get support?”

There are also concerns rising prison violence could represent significant risk to pregnant women. One woman told The Independent: “When I was pregnant there were fights kicking off around me all the time, I was so frightened something would happen to my baby.”

Another woman told The Independent of her distress when she was handcuffed while eight-months pregnant on her way to a scan. She said: “It was so stressful and humiliating - where did they think I was going to run to, while eight months' pregnant?”

Women also say prison staff are present during labour. One woman told The Independent that two female guards were stationed in the hospital room while she was in labour. She was acutely distressed by their presence and felt unable to push when she felt contractions while they were watching. She says she subsequently had to have an emergency c-section because of this.

One woman said: “When I was there, every single mother had a caesarean section - we all felt that it was because we were stressed and the officers were in the room all the time. I was in deep labour and I couldn’t really speak but I know they were there, I can still see their faces.”

Another woman said male guards were present at her birth until she had a c-section and they were excluded from the operating room on medical grounds. They later returned and she had to ask them to leave so she could breastfeed.

She had suffered a high risk birth and experienced heavy bleeding throughout her pregnancy while in prison. She says shortly after the emergency c-section and arduous birth the prison guards pressured her into returning to prison instead of recovering in hospital, telling her prison staff had to be paid extra to guard her during overnight stays in the hospital and the prison governor was worried about costs.

Unlike many countries which make allowances for women who are pregnant in the criminal justice system, the UK imprisons pregnant women and babies until 18 months (Getty Images)

Birth Companions is calling on the Government to issue clear guidance on how prisons and prison staff should treat pregnant women and babies inside jails. Director Naomi Delap told The Independent that some prisons treated women and babies well and were aware of their statutory duties to them, but many others seemed unaware of how to treat them with appropriate care and dignity. She said: “Prisons were designed with men in mind. Women are a small population, pregnant women are an even smaller one within that and many of the institutions haven’t really addressed the issue and the impact of current policies.

“Prison staff and healthcare workers often don’t know what they should be doing. Some prison staff can be hugely supportive, but others don’t know what they’re doing. Women need to have choice and to have their wishes and dignity respected in these difficult circumstances.”

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Shadow Lord Chancellor, Charlie Falconer, told The Independent: “I welcome the work done by Birth Charter and urge the Government to include measures to reform the way the criminal justice system treats pregnant women and mothers with children in its forthcoming prison reform bill.

“Sending pregnant women, or a woman who has a child they are caring for under 18 months old, to prison, should be a last resort and implemented only for the most serious of offences.”

Women’s Minister, Caroline Dinenage, told The Independent: “As the Prime Minister has made clear, this Government is committed to improving the treatment of female offenders.

“We are looking into options including tagging, problem solving courts and alternative resettlement units to improve our care for female offenders. This is particularly important if they are pregnant or have young children.