More than 90 women aged 50 and over gave birth last year, although the numbers are falling, data shows.
New figures from the Health and Social Care Information Centre (HSCIC) reveals the spread of age groups among women giving birth in English hospitals in 2014/15.
The number of births to girls aged 14 and under rose slightly to 143 from 133 the previous year, but there were fewer to women aged 50 and over.
The new data showed there were 23,262 births to teenagers aged 15 to 19.
Experts said unplanned pregnancies happened to women aged 50 and over who presume they are no longer fertile, although older women are also turning to donor eggs and IVF.
Among those aged 50 and over, there were 94 births in 2014/15, down slightly on the 107 the previous year and the 114 in 2012/13.
But the number of women having babies in their 30s is rising and there are still high numbers in their 40s having babies.
There were 23,194 births to women aged 40 to 44 and 1,298 births to women aged 45 to 49 in 2014/15.
Most births were to women in the 30 to 34 age group, with 194,086 deliveries.
Among women aged 35-39, there were 102,711 deliveries.
Overall, women in their 30s accounted for 47% of all deliveries and this is the only age group with increasing numbers of births.
A spokeswoman for the British Pregnancy Advisory Service (Bpas) said: "The overall average age of motherhood is increasing as women wait longer to begin their families, and complete them later.
"Maternity services need be organised to ensure they can cater for the slightly different needs of older women, who may be more likely to deliver by Caesarean section.
"A small number of women in their 50s gave birth last year. Accidental pregnancies have long occurred among women of this age, who may well believe they are no longer fertile, but they may also be the result of assisted conception.
"Whatever the age a woman decides to have a baby, her choices should be supported, and she should have access to the best possible maternity care and postnatal support."
Some 26.5% of all deliveries in NHS hospitals were by Caesarean section (up 0.3% in a year), rising to 36% among women aged 35 and over.
Most Caesareans were to mothers in Essex (28.8%) and London (28.7%). London also had the highest rate of all deliveries to mothers in their 40s.
Overall, the number of deliveries across England has fallen and is now the lowest recorded since 2006/07.
There were 636,600 deliveries, a 1.6% drop since 2013/14 when there were 646,900.
Natika H Halil, chief executive of the Family Planning Association (FPA), said: "Figures from the Office for National Statistics released last year showed the number of women over 40 having a baby has risen fourfold in the past three decades.
"With that in mind it is important for women who are not planning to have children, or have completed their family, to continue to use contraception until menopause.
"When we see stories in the media about women struggling to conceive as they get older, it is easy to assume that as you get into your late 30s, 40s and beyond you might not need to use contraception any more."