Pregnant women in prison in England are three times more likely to be ­diagnosed with gestational ­diabetes than those on the outside, according to “alarming” new data.

Figures obtained through freedom of information (FoI) requests to NHS trusts providing healthcare to women’s prisons in England found 12% of women receiving care relating to pregnancy in 2023 were diagnosed with the condition, triple the national figure of 4%.

Gestational diabetes develops when the body cannot produce enough ­insulin to meet the extra needs of pregnancy. It can lead to complications in pregnancy and can increase the risk of developing type 2 diabetes later in life.

Laura Abbott, associate ­professor in midwifery at Hertfordshire University, said these figures were “alarming but not surprising”.

“We have known for many years that preterm birth is more common among ­incarcerated pregnant women, and this ­further highlights the severe health risks they face,” she said. “Gestational diabetes increases the risk of high blood pressure and pre-eclampsia, serious conditions that require early detection, good nutrition and careful obstetric management, which is extremely difficult in a prison setting. It can also increase the risk of stillbirth.”

There were 215 pregnant women in prison in England between April 2023 and March 2024, according to figures published by the Ministry of Justice. There were 52 births while in custody, 98% of which took place in hospital.

The NHS and Prison Ombudsman categorise all pregnancies in prison as high risk. Pregnant women in prison are seven times more likely to have a stillbirth and twice as likely to go into premature labour, according to data from FoI requests in 2022. In 2019, newborn Aisha Cleary died at HMP Bronzefield after her mother, who was in prison on remand, was left to give birth alone in her cell. Louise Powell, who gave birth to a stillborn baby in a toilet at HMP & YOI Styal in 2020 after her ­emergency calls went ­unanswered, told the Guardian last year: “No woman should have to give birth behind bars.”

Amelia, who asked to remain anonymous, was 16 weeks pregnant when she entered prison and was later diagnosed by the prison midwife with gestational diabetes. A specific meal plan was recommended by the NHS to help manage the condition, but Amelia said the prison refused to implement it, and refused her additional supplements and prescriptions. She said she was given mouldy fruit: “I remember being given raspberries that had blue fur on them, and when I complained to the officer, I was told that it was a privilege to get any fruit.”

Despite the additional risks associated with gestational diabetes, Amelia missed midwifery appointments and developed high blood pressure and sciatica during her pregnancy. “I have previously had a miscarriage and this was my miracle pregnancy. I was terrified I would lose another baby,” she said.

Amelia’s sentence was overturned during her pregnancy and, a week after her release, she went into premature labour, having an emergency c-section, which she attributes to the high stress and poor health caused by the prison environment. “I’m quite a strong person, but I’m mentally scarred by the experience I had being pregnant in prison. I still wake up in a sweat with night terrors, and I rarely go out of my house now. Prison is so unhealthy – not only for mothers, but the baby as well. I’m so grateful to be out, but the effects of being pregnant in prison will be everlasting.”

In April last year, the Sentencing Council introduced pregnancy as a mitigating factor for judges when sentencing. As the Independent Sentencing Review published its initial findings last week and the government’s newly appointed Women’s Justice Board begins work, to reduce the number of women sent to prison, calls are growing to end the imprisonment of pregnant women.

“Prison is no place for pregnant women. There are better, safer alternatives, such as ­community sentencing, which should be prioritised wherever possible,” says Clare Livingstone, professional policy adviser at the Royal College of Midwives. “The RCM believes that the sentencing of pregnant women needs radical reform. We believe every aspect of the criminal justice system should be aligned towards ensuring mothers and babies are kept together, wherever possible, in the best interests of the child.”

Janey Starling, co-director of Level Up, a feminist campaign group, said: “Prison will never be a safe place for pregnant women. Several other countries, including Costa Rica and Brazil, have laws against the use of imprisonment for pregnant women and mothers. It’s time the government follows international best practice and ends the profoundly cruel practice of incarcerating pregnant women, and mothers and babies.”

A government spokesperson said: “This account is deeply concerning. It is an example of why the Lord Chancellor has launched the Women’s Justice Board so that fewer women end up in prison, particularly those who are pregnant or mothers.

“We have specialist midwives and pregnancy, mother and baby liaison officers in every women’s prison, and NHS England now treats all pregnancies in prison as clinically high risk.”