Mothers have a right to consistent standards wherever they live

Roger Taylor, Dr Foster

Ipswich hospital tops the list with 1.3 births every day for each delivery bed, compared to the national average of 0.76 births per day.

The maternity units with most pressure on beds are large hospitals, usually in major cities, according to the guide, published by independent health care company Dr Foster.

"This research reveals for the first time an unexpectedly high degree of variation in the number of births per bed in British maternity units," said Roger Taylor, editor at Dr Foster.

"That is not to say there is a similar difference in the quality of care, but there will be some pressured units which are operating with substantial overcrowding.

"Mothers have a right to consistent standards wherever they live."

Midwife shortages

The Royal College of Midwives (RCM) says staffing levels are under tremendous stress.

RCM deputy general secretary Louise Silverton said: "This shows how precarious the service is at the moment and under resourced.

"The government is putting in a lot of effort, but returnees to midwifery are few.

"It's almost like running the tap and pulling the plug out."

Hospitals with more than one birth per bed per day

Ipswich - 1.3 Solihull Hospital - 1.3 Royal Devon and Exeter Hospital - 1.3 Kingston Hospital, London - 1.2 Royal Sussex Hospital - 1.2 Birmingham Heartlands Hospital - 1.2 Whittington Hospital, London - 1.2 Birmingham Women's Hospital - 1.2 Royal Infirmary of Edinburgh - 1.2 Leeds General Infirmary - 1.2 Walsgrave Hospital - 1.1 Norfolk and Norwich Hospital - 1.1 John Radcliffe Hospital, Oxford - 1.1 Ninewells Hospital, Scotland - 1.1 Milton Keynes General Hospital - 1.1 Nevill Hall Hospital, Wales - 1.1 Ulster Hospital - 1.1 Wexham Park Hospital, Slough - 1.1 Queen's Medical Centre, Nottingham - 1.1 Royal United Hospital, Bath - 1.1 King George Hospital, London - 1.1

Smaller units and community hospitals offering a midwife-led service tend to have far fewer births per bed, the data shows.

The guide reveals Caesarean rates in some large hospitals are twice the level of others even after adjusting for differences in the types of people served by the unit.

In the south west, an average of 7% of mothers opt for an elective Caesarean, while in Northern Ireland and Wales, the average is 10%.

At London's exclusive private Portland Hospital, planned Caesareans are common, with 26% of women choosing this option last year.

This compares with a London average of just 8%.

Parents wanting a home birth can assess which units are most successful at providing this service.

Other topics covered include pain relief and ante-natal screening.

The data was collected from hospitals by Dr Foster after consultation with the National Childbirth Trust, Royal College of Midwives, Royal College of Obstetricians and Gynaecologists and the Department of Health.