Poor standards of care in maternity units may be causing long-term health problems for mothers and babies, the NHS inspectorate warns in its annual report published today.

The Healthcare Commission says "weak managerial or clinical leadership" is often the root cause of poor performance because problems are left unidentified or unresolved.

Sir Ian Kennedy, its chairman, said yesterday that some maternity services were "not as good or as safe as they could be". But he feared that units with high death rates were only one part of the story, as poor standards might be jeopardising the health of mothers and children long after they leave hospital.

In a drive to raise standards, the commission will ask all health trusts to review immediately their maternity provision to learn lessons from three hospitals it studied after concern over high death rates - Northwick Park Hospital in Harrow, north-west London, New Cross Hospital in Wolverhampton and Ashford St Peter's Hospitals, south-west of London.

Common problems included poor reporting of incidents and handling of complaints; poor working relationships and poor co-operation in multidisciplinary teams; inadequate training and supervision of clinical staff; poor environments with services isolated geographically or clinically; staff shortages coupled with poor management of temporary workers.

The commission says the problems extend beyond safety and many relate to the general quality of care. They include doctors and midwives not having time to explain what is happening to patients; lack of advice on feeding, bathing, settling, and the health of the baby or mother; overcrowding and poor standards of cleanliness in lavatories and bathrooms; delays caused by faulty equipment; lack of information for bereaved families and women whose first language is not English.

Failures in maternity service account for more than 70 per cent of NHS legal disputes, reflecting the lifelong consequences of birth-related disabilities. One in 10 complaints about the NHS relates to maternity care.

The commission is worried that some trusts cannot monitor their own performance because they do not collect enough information. Full data for only 72 per cent of births in England was provided in 2003-04.

In future, organisations which fail to supply enough information will face greater scrutiny. They will be more likely to face a spot check, which could affect their annual performance assessment.

Sir Ian said: "The commission wants to work with those providing services, including midwives, doctors and managers, and their professional organisations. We want to bring all units up to the standards of the best. We need a fresh, co-ordinated effort to raise standards and get the risks as low as possible."

Although he said very few mothers and babies died or suffered serious damage, the numbers could be smaller "if we threw the spotlight on maternity more often, and not just in the aftermath of a serious problem".

The commission will launch a series of national studies on maternity services to explore the risk factors already identified. One issue will be the relationship between high maternal death rates and social deprivation after a study showed that women from deprived areas were 45 per cent more likely to die than those in affluent areas. Women from minority ethnic groups were, on average, three times more likely to die.

It wants primary care trusts, which commission the services of maternity units in hospitals, to use the risk factors revealed by its study to assess the performance of these units.

A recent survey by the National Childbirth Trust suggests maternity services are not meeting the needs of women. Some 58 per cent of respondents said the environment was too clinical and 49 per cent said they had no control over who came into the room.