A maternity unit has been criticised severely by a healthcare watchdog following the deaths of 10 women who gave birth at the same hospital.

The Healthcare Commission blamed system failures, weak leadership and a poor quality of care in nine out of the 10 cases at Northwick Park Hospital in north-west London.

The watchdog renewed its call for all NHS trusts to check that they had robust systems for monitoring the safety of maternity units as the report described what had happened to each of the 10 women, all of whom died during pregnancy or within 42 days of giving birth between April 2002 and April 2005. The number of deaths was more than six times the national average, where about one woman in 8,775 dies in childbirth.

The investigation into the North West London Hospitals NHS Trust found a catalogue of failings.

Difficult decisions were often left to junior staff, the report added, the hospital failed to respond quickly when a woman's condition changed unexpectedly and it had inadequate resources to deal with high-risk cases.

The report found there was a reliance on agency and locum staff without adequate managerial support.

The trust's board was also criticised for failing to appreciate the seriousness of the situation.

In April last year, the Healthcare Commission was called in to investigate maternity services at the hospital amid concerns over the high number of deaths.

Five of the families of the 10 women, who were in their twenties, thirties and forties, met the investigation team to discuss the report and a sixth family responded in writing. The North West London Hospitals NHS Trust said lessons had been learnt and improvements made at the hospital.