Key to infertility in older women is revealed

A protein, known as securin, may be behind the high cases of miscarriages in older women. Photo / 123RF

An older woman's chances of having a miscarriage or a disabled baby could be slashed thanks to a new scientific breakthrough.

Scientists may have pinpointed one of the leading causes of genetic abnormalities in the eggs of older women, which often leads to miscarriages and disabilities.

Researchers have found a fault in how eggs from older women control levels of a protein known as securin, reports Daily Mail.

The discovery may help to unlock the key to infertility in older women and help tackle high levels of miscarriages and deformities.

Female fertility declines rapidly after the age of 37 - with women over 42 having only a five percent chance of having a baby without fertility treatment.

Researchers from Monash Biomedicine Discovery Institute (BDI) and University College London found that insufficient levels of the protein securin may give answers as to why older women have higher incidences of miscarriage and other complications.

Securin is important for cell division, which influences the number of chromosomes present in an egg.

In older women, insufficient protein levels appear to particularly influence the later stages of cell division, known as meiosis II.

Yet, most chromosome abnormalities arise from mishaps occurring in early cell division, known as meiosis I, the researchers add.

An example is Down's Syndrome, where the fetus has three copies of chromosome 21.
The protein may also play a role in fertilized eggs that fail to implant in the womb, resulting in miscarriage.

The researchers, writing in the journal Nature Communications, believe their findings help explain why things go wrong in the second stage of cell division.

Dr Ibtissem Nabti and Professor John Carroll from the Monash BDI said new approaches to improving egg quality in older women is important as women are waiting increasingly longer to start their families.

Professor Carroll said: "It is immensely challenging because any treatments need to be safe for the egg and subsequent embryo, and would usually need to be applied while the egg is in the ovary.

"It may one day be possible to perform treatments in-vitro (in the laboratory) but human in-vitro egg maturation is not yet very successful.

"Now that we have an idea of at least one of the causes of the increased incidence of chromosomal abnormalities and miscarriages in older women, we can attempt to find ways to prevent this happening."

It is not yet known why securin levels deplete in older women. The researchers are investigating ways to prevent this decline.

This comes after news that researchers from Northwestern University's Feinberg School of Medicine and McCormick School of Engineering, both in Illinois, are using 3D printed ovaries to allow infertile mice to give birth.

While it has only been tested in mice so far, the researchers hope the technique could one day be used to help women who are unable to have children.