It is an irrefutable fact that with the progression of age, the female body's ability to bear a child decreases. It has been a mystery why this may be the case — until now.
A new study may finally be able to provide an answer to this question. A group of scientists from the University of Montreal Hospital Research Center conducted extensive research, which offers clues about female infertility.
How Was The Study Conducted?
The study was conducted on older mice. Using state-of-the-art microscopic technology, researchers were able to determine a specific defect in the eggs belonging to the creatures. Scientists believe that this same defect may be present in the eggs of older human females, which causes complications while conceiving.
Scientists carried out micromanipulations on mice eggs. The mice whose eggs were tested were aged 6 and 12 weeks, which is considered to be young for the creatures. The same procedure was followed for the eggs of 60-week mice, which is considered old.
Researchers swapped the nuclei of the young eggs and placed them in the older eggs. They then observed the complications that arose following this change, which aimed to determine the cause of age-related infertility.
Female Infertility: The Possible Cause
The researchers found that the cell division process became distorted after the nuclei swap, which prohibited proper chromosome sharing to occur. This sharing is required for a pregnancy to initialize.
"We found that the microtubules that orchestrate chromosome segregation during cell division behave abnormally in older eggs," stated professor Greg FitzHarris, a researcher at CRCHUM.
He added that this abnormal movement of the microtubules is essentially what causes age-related infertility among females.
"One of the main causes of female infertility is a defect in the eggs that causes them to have an abnormal number of chromosomes. These so-called aneuploid eggs become increasingly prevalent as a woman ages," explained FitzHarris.
The 'Cohesion-Loss' Concept
Previously, the scientific community believed that age-related infertility in women was caused by the improper working of the "glue" that kept chromosomes together. This theory is known as the "cohesion-loss" concept.
However, the current research asserts that the study does not disprove the cohesion-loss theory. It only postulates that there could be another reason behind the phenomenon.
The results of the latest study could pave the way for future treatments, which would perhaps address age-related infertility among women and aid in rejuvenating the eggs. However, researchers are quick to point out that such advancement would take several years as this study is just on a basic level.
Many such similar studies would need to be conducted to learn more about these defects, before an effective treatment can be developed.
The findings have been published in the journal Current Biology.