Deborah Orr: Despite Mrs Hewitt's best intentions, British women will be no closer to a natal nirvana

Who wouldn't want a perfect home birth, with no complications, a bit of gas and air, ana good midwife?

Wouldn't it be great if every fertile woman in the country could contrive to conceive in April 2008, opt for a home birth, and then yell in January 2009, between labour pains: "See? Told you target-based policy is irritating and meaningless!"

Because, of course, quite a number of the women opting for home birth in this mass demonstration would not, despite Patricia Hewitt's promise of yesterday, have a familiar and befriended midwife in the bathroom to shout at, which in turn would serve us right for using our babies to make a political point, when there are plenty of politicians around to do that for us.

Who wouldn't, in an ideal world, want a perfect home birth, with no complications, a bit of gas and air, and a really good midwife? Who wouldn't, at least, want something like that to be an easily accessible option, for those who are keen on it and are capable of attaining it? That's the beauty of the minimum-standard maternity guarantees given yesterday by the Department of Health. The sentiment is unarguable.

The NHS should do all it can to ensure that women give birth in the way they wish to, with a suitable level of expertise and technology available. Indeed, it has been Government policy to achieve such nirvana since the publication of Changing Childbirth in 1993. The trouble is that in the intervening 14 years, the likelihood of actually receiving such care has declined rather than improved for very many women, even though nobody apparently wants it to be that way.

Maternity services vary around the country. My own experience of NHS childbirth was absolutely appalling, twice, except for the fact that the first time they did manage to save the life of my sky-blue son, and the second time they did manage to stop me from making a permanent exit myself. The emergency care was great, and the rest was utterly abysmal. Certainly there is plenty of room in some trusts for the sort of improvements that Mrs Hewitt has outlined.

For others, though, the experience is much better. In parts of the country with well-organised and well-staffed midwifery units, up to 12 per cent of women opt for home births. But to illustrate how much more patchy that service has become, it should be noted that in 1973 there were 527 units offering a variety of services from midwifery-led to obstetrician-run services, that by 1996 there were 341 and that by 2004 there were 282.

The trend, despite all lip-service towards earth-motherly squatting behind the sofa, has been in favour of big, highly medicalised units. According to figures from Reform, an independent think-tank that compiled a policy document on NHS maternity services in 2004, the largest of these is Liverpool Maternity, which in 2003 delivered 8,084 babies.

In France, the largest unit at that time had delivered 4,000 per year and in Germany 3,000. Both countries did far better than Britain, needless to say, in the notorious Unicef report card on childhood in developed countries, with Britain coming fifth from the bottom of the league on low birthweights and sixth from the bottom on deaths before the age of 12 months per 1,000 live births. But that damning pair of statistics seems to have given no one pause for thought on whether centralisation of maternity services is really a good thing.

The latest promise is that we can now choose between home birth with a midwife, birth in a local midwife-led unit or birth at a hospital supervised by a consultant. The catch is that between the first two - suitable for women who have a low risk of complications - and the last - suitable for women with a high risk of complications - there is something of a gap (if Government plans turn out, by strange chance, as they are meant to). If you're medium-risk, and fancy hedging your bets, then your choices aren't going to be quite so great.

It may seem odd that while this fantastically rich revolution in maternity care is being planned, the Conservatives are able to allege that no fewer than 43 maternity units are under threat of closure. It may seem odd also that no fewer than five government ministers - including Hazel Blears - have seen fit to contradict their government's policy by campaigning against maternity unit closures in their own constituencies. But it isn't, really.

The emphasis is being put on greater provision of midwives because that's the good news story. Really, though, it is a by-product of the Government's more general health policy, which is to concentrate more specialist equipment and knowledge in regional super-centres, so that technology and expertise can be concentrated on single sites, while as much in the way of chronic conditions as possible can be treated in the simplest possible way - by GPs, on the internet, at walk-in centres, or, hey, at home with a midwife.

Is this, in general terms, such a bad idea? Maybe not, although we might all have a bit more confidence in it if two things were happening. First, this restructuring project would seem much less suspicious if government ministers started describing the policy to us as if we were grown-ups, instead of coming up with touchy-feely spin-led ways of presenting its more plausibly saleable consequences in a fashion they think will appeal to us.

Second, the endless rush towards central, directive-led control would all be much less scary if the plank of the Great Plan that was designed to parachute a lot of efficient institutions away from the dead hand of centralisation - foundation hospitals - hadn't been so watered down as to be almost useless. Surely good local hospitals, not central government, are best placed to decide whether they need to keep an obstetric-led maternity unit, or can manage perfectly well with a midwife-led clinic? The idea that this kind of decision can be made from the top down, with little regard for local pattern-of-use, is weird.

Yet even if these two large difficulties were one day magically overcome, there would still be nagging worries about this sort of organisation for maternity services in particular. Childbirth is a funny thing, and it doesn't always lend itself to triage, even at the best of times. Plenty of women I know, of all ages, have approached childbirth in the confident belief that they are fully healthy and fully prepared, only to find themselves having an emergency caesarean, or begging after hours of exhausting labour for the epidural they swore they'd never have.

Such unforeseen circumstances will only be catered to, under these policy directives, surely, if you chose a super-centre birth in the first place, or are near enough to get to one in time. Since even in a top London teaching hospital you can find yourself being told that you can't have an epidural because "it's too late" or because there's no anaesthetist available, that's not such a stunningly flexible array of choices, after all.

d.orr@independent.co.uk