One in four births in England is now emergency caesarean, BBC analysis shows

She says reasons for the rise are largely unknown, adding there is "no clear and consistent reporting". And she says it will not be possible to explain increases without "good quality data" about why operations are performed.

Prof Thangaratinam says she also wants to explore what part race has to play. While the national average for emergency C-sections is one in four births, it is about one in three for black and Asian mothers.

Prof Knight is investigating whether factors like age, obesity and pre-existing medical conditions are contributing to the increase - but she says NHS staff and mothers may also be influenced by high-profile maternity scandals.

For years, maternity units were told to keep rates of caesareans low. Those targets were dropped in 2022.

Recent maternity safety scandals in Morecambe Bay, East Kent and Shrewsbury and Telford all heard similar, devastating stories of mothers and babies dying and a reluctance to do caesareans. Ongoing inquiries in Nottingham and Leeds are likely to have similar concerns.

"We also need to recognise the potential impact of rising fear among women, families and staff, which may lead more to choose or to recommend caesarean birth," she says.

Another health professional told the BBC no one wants to be the next scandal.

Over the last five years, there has also been an 11% increase in the number of legal claims against the NHS for maternity problems.

"Legal cases typically question why caesareans are not undertaken or not undertaken sooner," Prof Knight says. "Doctors and midwives are rarely criticised for performing an early caesarean."

NHS England says "many factors" influence caesarean births and its "priority is always the safety and wellbeing of both mothers and babies".

The BBC spent two days in the maternity unit at Northwick Park Hospital in London and met 18-year-old new mum Khushi.

She had an emergency caesarean because her baby's heart rate kept slowing down during labour. It was classed as category one, the most urgent type.

Khushi says she was baffled and scared - that she had no clue what she was getting herself into.

"It was my first ever surgery. Just the thought of being open on a table still feels so surreal and so unbelievable," she adds.

Now at home with baby Aarav, she faces six weeks physical recovery from the major surgery, but says the mental trauma is the hardest part for her.

Dr Alison Wright, president of the Royal College of Obstetricians and Gynaecologists, has been delivering babies for 35 years. She worries how services will adapt to the increased number of emergency C-sections.

She says many maternity units already don't have enough dedicated obstetric theatres.

"If we do not invest in our workforce and in our operating theatre capacity, we may be in a position in the future where we cannot do the emergency caesareans we need to," she adds.

Prof Ed Wilson, health economist at the University of Exeter, says that according to NHS data, a routine vaginal delivery is almost £4,800. A planned caesarean would be about £6,000.

But he estimates that emergency C-sections cost almost £9,000.

An NHS spokesperson says: "The increase in the number of emergency caesarean births is influenced by many factors, and our priority is always the safety and wellbeing of both mothers and babies.

"Decisions are made by considering individual circumstances and clinical advice to ensure the safest and most appropriate approach for each birth."

The Department of Health and Social Care says it was committed to improving maternity and neonatal safety and pointed to Health Secretary James Murray's role as chair of the national maternity taskforce.