Women in labour are turned away from a Sussex maternity unit more often than almost anywhere else in England.

The unit at the Royal Sussex County Hospital in Brighton was closed to new admissions on 16 days in the last year.

The number of hours the unit closed ranged from four to ten at a time.

The hospital has the fourth-highest closure rate in England and Wales according to figures published today in The Times Good Birth Guide.

The guide is compiled by medical research group Dr Foster, which has been investigating all hospital maternity units.

The maternity unit deals with almost 3,500 births a year.

A combination of any unexpected rush in births, staff shortages and sickness can add to the pressure, forcing the unit to close.

Hospital bosses admit it can be upsetting for women who have been getting regular antenatal care from a hospital to be sent elsewhere when they go into labour.

They insist it is only done as a last resort.

A spokesman for Royal Sussex said: "We closed the maternity unit to new admissions on 16 occasions during the year in question. Some of these were for as little as four hours.

"The total period during the whole year was 135 hours - in other words we were open for 98.5 per cent of the year.

"The unit is only ever closed if the senior midwife believes that client safety would be compromised if it were left open.

"It is closed when the ratio of mums-to-be to midwives causes concern. This happens when staff sickness or recruitment becomes a problem or when we get overloaded.

"We are a very busy unit with one of the highest delivery-to-midwife ratios in the country.

"If we do have to close, an agreed protocol is followed and expectant mums are advised to go to one of the other units with which we have a reciprocal arrangement.

"If a poorly mum turns up unannounced then we would invariably see them despite being closed as it would be possibly more risky to transfer them to another hospital.

The Brighton hospital is one of three in Sussex to feature in the top 20 hospitals who have closed most often.

Princess Royal Hospital in Haywards Heath is fifth on the list after closing 13 times in the last year.

Worthing Hospital, which closed four times, is ranked equal 11th.

Brighton and Sussex University Hospitals NHS Trust, which is responsible for both Royal Sussex and Princess Royal Hospitals, is working on a business case to apply for more money to recruit extra midwives.