"Older" mothers are giving birth birth in record numbers and this is putting midwives and maternity units under "intense pressure", a report has revealed.
There were 6,859 more babies born in England and Wales to women in their 30s and 40s in 2014, than there had been in 2013.
The number of births to women aged 30 to 34 has been greater than 200,000 since 2010 - a level previously not seen since the 1930s.
Women over the age of 40 giving birth has risen from 14,252 in 1999, to 29,010 in 2014, the State of Maternity Services Report 2015 from the Royal College of Midwives (RCM) stated.
The report argues the NHS is short of around 2,600 midwives.
This shortage is made worse, the report states, by the ageing of the midwifery workforce.
The number of midwives in England aged 50 or over has doubled from 4,057 in 2001, to 8,169 in 2014.
RCM chief executive Cathy Warwick said: "All women deserve the very best care, regardless of the age at which they give birth.
"Women have every right to give birth later in life, and we support that. But typically older women will require more care during pregnancy, and that means more midwives are needed."
Warwick said it was "deeply frustrating" for midwives that they're unable to provide the quality of maternity care they want to deliver because they are so short-staffed.
The report also showed there were 661,496 babies born in England last year overall, almost 100,000 higher than in 2001.
Warwick added: "It would be far better if midwives could spend more time helping pregnant women to quit smoking and helping new mums to breastfeed, if they choose to do so.
"Too few midwives also means less time with women, with rushed midwives potentially missing signs of postnatal depression, for example."
Siobhan Freegard, founder of video parenting site Channel Mum told HuffPost UK Parents: "Mention older mums and people panic, but as these figures show they are nothing new.
"Giving birth later in life was common in the 1930s and 1940s when families were larger.
"But what's new is women now wait longer to have their first child and the rise of IVF pregnancies, which may need closer monitoring.
"Many of these pregnancies do need extra care and the midwife shortage means medical staff are struggling to give every mum the attention she needs."
Warwick said her main concern is the "retirement time bomb" that was unearthed in the report, showing not enough new midwives are being taken on.
She said: "We must see action now, including protecting or expanding midwifery training numbers and, just as importantly, making sure newly-qualified midwives get jobs in the NHS once they’ve qualified."
