By Branwen Jeffreys
Health correspondent, BBC News
Research shows that for low-risk women giving birth at home is as safe as doing so in hospital with a midwife.
But there is a very significant variation in the home birth rate across the UK, from barely more than 1% in some areas to as high as 10% to 12% in others.
It is a gap that can only partly be explained by different policies on maternity services.
Julie's elder daughter slept while her mum gave birth at home
Wales has the highest average rate of any of the UK nations and is the only one to have set a specific target.
In 2002 maternity services were asked to reach a 10% home birth rate by 2007.
It was a very ambitious target and many areas haven't managed to reach it, but in some it has transformed the choice in maternity services.
The small, bright birth centre in Brecon is part of the Powys maternity service which looks after pregnant women across a huge rural swathe of mid Wales.
It is tiny compared to many large hospital units, with a birth pool suite, another delivery room, a bedroom for women to rest and a kitchen.
The midwives here are out on the road much of the time, visiting women for antenatal care or delivering babies at home.
Staying at home
Julie Richards, the head of midwifery for the Powys health board, says they offer home birth as a realistic choice for women who are low risk. That means a careful assessment at every stage.
"We usually reassess at the birth plan appointment around 38 weeks to discuss again whether the pregnancy has remained normal, uncomplicated and low risk and remind them the option of home birth is there.
"Obviously when women ring up in labour we go back over that and give them the chance of a home assessment to see if they can continue with a home birth. "
The 42 midwives in the service have to work very flexibly across a large area coping with an annual caseload of around 1,200 births. The service is now consistently achieving a homebirth rate of 10-12%.
Julie Richards is clearly proud of the changes which she says have led to a shift in thinking in which they staff the community service rather than just thinking about staffing the buildings.
Unlike many maternity services they do not have to staff a large obstetric unit at a hospital.
Their rural service has to transfer women to hospitals in north and south Wales as well as across the border into England if they need the care of a doctor or decide they want access to an epidural.
Each year around 15% of the home birth mothers are transferred during labour with journey times that can be up to an hour.
Just outside Hay-on-Wye on the border between Wales and England I visited Julie North, one of the mothers who has recently had a home birth with the Powys maternity service.
Her second daughter Isabelle was born just over six weeks ago, during the night while her two- year-old sister Bethan was fast asleep.
The privacy of being at home and convenience of not having to find someone to look after Bethan was part of the decision to choose a home birth, but Julie was also reassured by knowing a number of other women who had made the same choice.
"I'd say that made a big difference, being able to talk to friends who'd had good experiences. It allayed any fears I had, tales you hear about things that go wrong at home, I heard more good things than bad things."
Women in many other parts of the UK might not be able to draw on a similar range of experience of home birth among midwives or their peer group.
The range in the home birth rate suggests that it is driven in part by the willingness of maternity services to offer it as a choice for appropriate women.
There has also been a lack of significant research on the safety of home births, which was highlighted when NICE published its guidelines on birth in 2007.
In the light of that lack of evidence the guidelines at the time said if something goes unexpectedly seriously wrong during labour at home "the outcome for the woman and baby could be worse than if they were in the obstetric unit with access to specialised care".
A major research project, Birthplace, is now being carried out by the National Perinatal Epidemiology Unit at the University of Oxford.
It will follow women through labour to compare the safety of home, midwife led units and obstetrician led units for mothers and their babies.
While childbirth in the UK is generally very safe by international standards their research should provide women with much better information to make an informed choice.