Yesterday Jack Straw declared reclaiming the "unfashionable" concepts of punishment and reform would not herald a Victorian approach to crime. Yet, with the publication this week of figures showing the number of babies born in prison is soaring, you don't need to read Little Dorrit to feel there's already something very Dickensian about our prison system.

Ministry of Justice figures show that between April 2005 and July 2008 an average of 1.7 babies were born behind bars. But between April and July of this year, the rate has more than doubled to almost four a week and the total for this year could reach 200 births.

Pregnant women prisoners are often beset with anxieties. One young woman told Prison Reform Trust researchers:

Social services cropped up a few times. I'd been in foster care myself anyway. I'd sit there at night thinking I've done drugs, I've done crime. They might think I'm a bad mother automatically because of these things. Am I going to get my baby taken away from me? Am I going through all this for nothing? There were lots of questions I'd sit there asking myself that I couldn't answer because I didn't know.

It's hard to think of a more depressing place to start life than in one of the eight mother and baby units located in our prison system. However committed the staff and improved the conditions, prison is no place for children.

In addition to those born in prison, many more children are affected by the imprisonment of a parent. Through no fault of their own they are at greater risk of poverty, bullying and poor health than other children. Yet they remain invisible to government.

Although it's unclear why the figures shot up so dramatically since April there's little doubt that the general upward trend in babies born in prison reflects the huge increase in the number of women prisoners. The number of women in prison has almost doubled since 1996 and now stands at nearly 4,400. In the course of one year about 18,000 children will be affected by their mother's imprisonment.

As the government's Corston review found last year, many of these women are damaged individuals who pose no risk to the public. Over a third of women in prison have no previous convictions – more than double the figure for men. The review confirmed what anyone who's been inside a women's prison will tell you, many women prisoners become trapped in a cycle of deprivation, domestic violence, drug abuse and crime that the prison system is failing to break. The Ministry of Justice has to come to terms with the inconvenient truth that most women in prison have been both perpetrators and victims of crime.

That's why the Corston review called on the government to establish – as an alternative to prison for the overwhelming majority of women offenders – a network of support and supervision centres to administer community sentences and help women offenders address the root causes of their offending and take responsibility for their lives and their children.

One young mother told the Prison Reform Trust:

If there was a place between a prison and a home – but not a hostel – somewhere where people could help and teach you real things so you can live and not have your baby taken away. It might help stop girls doing drugs or stealing or whatever. Somewhere that was clean and like a home. I would like that.

Although the government accepted the Corston review in principle, and despite the obvious commitment of a number of ministers, the worry is that when it comes to implementation, these quiet but invaluable reforms will be squeezed out by the need to fund the flawed flagship titan prisons.

The conditions in prison may no longer be Dickensian but young mothers are still going to jail for the same reasons they were in Victorian times: poverty, debt, addiction and mental illness.

This blog first appeared in Comment is Free