Internal investigations are underway after a seven-week old baby died from whooping cough.

The child, who has not been named, was born at the Norfolk and Norwich University Hospital and treated by its maternity service.

Its death from the illness, also known as pertussis, has prompted an investigation into the antenatal care provided.

The hospital originally reported the baby's age as seven days, but has since clarified that the child was seven weeks old.

Another review is also being set up into the deaths of two other maternity patients, and two 'near-misses'.

The N&N said it was carrying out the reviews to ensure that staff learn everything possible from each case in order to 'drive continuous improvement'.

And improving maternity services in the region has been identified as a top priority for hospital chiefs working on the Norfolk and Waveney Sustainability and Transformation Plan (STP), this newspaper can reveal.

According to N&N documents a review was carried out after two previous maternal deaths. Since then a further three deaths have occurred, plus two near-misses - prompting a 'thematic review of the cases'.

One of those deaths was the baby who died of whooping cough.

The illness, a bacterial infection of the lungs, can affect anyone but is more dangerous for babies and young children.

However death from whooping cough is extremely rare - with only four such reported cases across England and Wales during 2015, according to Public Health England.

Latest figures show there were 242 cases of whooping cough in Norfolk, Suffolk, Cambridgeshire, and Essex in 2014, with just eight patients aged less than one year affected.

The reason the numbers are so low is that there is a national immunisation programme for children, and pregnant women are also advised to have immunisation by their midwife.

This is carried out at GP surgeries - however a spokesman for the N&N said the hospital trust is in the process of agreeing a pilot programme which would see its maternity service administer whooping cough and influenza vaccinations.

The hospital trust does not currently vaccinate pregnant women for whooping cough or seasonal flu.

Instead its maternity service merely provides information to the patients.

But that is set to change when the trust agrees the pilot deal with the local branch of NHS England (Midlands and East).

'These vaccinations will be given to eligible pregnant women booked at the trust and receiving antenatal care from the community midwife,' the N&N spokesman said.

Meanwhile transforming maternity services has become a key priority for STP leaders - as they seek to devise a plan that will meet demand for healthcare in the region.

In August this newspaper reported how midwives at the N&N's maternity unit were tasked with looking after too many patients, because of a national shortage of people in the profession.

A spokesman for the STP said more details of changes to the region's maternity services would be made available 'in the coming months'.

Have you got a health story? Email nicholas.carding@archant.co.uk