Compared to children born of younger women, children born to mothers over 40 are less likely to have accidents or need hospital care and more likely to have been vaccinated early, a study has found.
They will also develop a broader vocabulary from a young age and achieve higher scores in IQ tests in a range of measures up to the age of five.
The research is good news for the rising numbers of mothers who are delaying motherhood.
Previous studies have highlighted the growing infertility rates for older women and the greater risk of them developing diabetes and pre-eclampsia.
But the latest research appears to show gains for older mothers once they have given birth, possibly due to their greater experience and maturity.
Researchers at the Institute of Child Health, University College London and Birkbeck College, London, said their findings showed older mothers could make better parents.
Dr Alastair Sutcliffe, who worked on the study, said negative publicity surrounding the rise of older mothers was based on the physical risks of pregnancy and childbirth.
"We have clear evidence that there are more desirable outcomes for children of older mothers compared with younger ages. We can reassure these older women that their children are probably better off," the Daily Mail quoted him as saying.
The study looked at 1,100 children born to women aged 40 and over, compared with 38,000 children born to younger women in Britain. The children's ages ranged from nine months to five years.
Dr Sutcliffe said older mothers might be more risk-averse, possibly because they were less active and unable to run after their children, but they may also be better at spotting and avoiding potentially risky situations.
The finding will be presented at The Royal College of Paediatrics and Child Health conference in Glasgow.