One in 10 mothers aged 40 and over gives birth to a premature baby, according to official figures.
Data from the Office for National Statistics (ONS) show 10.1% of babies born to mothers aged 40 or over were delivered before 37 weeks in England and Wales in 2011.
This is up slightly on the 9.5% figure for 2007 and compares to 6.7% of 25 to 29-year-old women giving birth prematurely in 2011.
The number of live births to mothers aged 40 and over has more than quadrupled over the last three decades from 6,519 in 1982 to 29,994 in 2012.
A normal pregnancy lasts about 40 weeks, with a delivery before 37 weeks considered premature.
Analysis by the ONS shows that part of the reason for the higher percentage of older mothers giving birth prematurely may be because they are more likely to have twins or triplets.
In 2011, 6.2% of babies born to mothers aged 40 or over were multiples compared with just 1.2% of babies born to mothers in their teens.
Only 5.6% of single babies are born premature, compared with more than half (53.1%) of babies who are part of multiples pregnancies.
The data also confirmed that younger mothers more likely to have babies who are small for their gestational age.
Premature babies are more likely to suffer health problems, including higher rates of disabilities such as cerebral palsy and even death.
Babies can also suffer breathing problems related to having immature lungs as well as jaundice and eye problems.
Louise Silverton, director for midwifery at the Royal College of Midwives, said: “This figures support our calls for enough midwives to provide care to the increasing number of older mothers who need more time, attention and monitoring throughout their pregnancy.
“It demonstrates that births are becoming increasingly complex as more older women give birth, along with other issues such as obesity.
“This also demonstrates the need for continuity of care for women which will reap benefits for older women who tend to have more complicated pregnancies.
“These women also need extra care after birth as they have a small baby or babies.”