Genes that let women conceive after age of 45

Some women have special genes that mean they can conceive naturally much later in life than most, doctors said today.

Researchers in Israel have found a group of women who have become pregnant over the age of 45.

Although unusual, there has been an increasing number of such pregnancies in recent years.

Cherie Blair gave birth to her fourth son Leo at 45 while actress Geena Davis had twins at 47.

Dr Neri Laufer, of the Haddassah University Hospital in Jerusalem, studied 250 women over the age of 45 who had conceived spontaneously.

He said: "Mostly they had had a large number of children and a low miscarriage rate, and these two factors indicated to us that they had a natural ability to escape the ageing process of the ovaries.

"We decided to see if we could find any differences in gene expression between eight such women and another six women of the same group who had finished their families at the age of 30."

It is hoped that more can be learned about the special genetic make-up of these women to develop better infertility treatments.

They were all Ashkenazi Jews but Dr Laufer does not believe the results will be limited to them as preliminary studies in other ethnic groups have been similar.