Decreased Ovarian Oxygen Affects Ageing Eggs

In recent years many couples have put building a family on the back burner for many reasons. Whether it is to build a career or ensure financial stability, the consequences of delaying pregnancy can mean difficulty or inability to conceive for some couples. It is well known that as a woman ages her eggs become less viable. Scientists have been unable to discover what exactly caused the biological clock to tick; however, new research from the Yale School of Medicine provides an answer to that question along with hope that fertility doctors may be able to use this information to help older women become mothers.

After the age of 35 a woman’s ability to conceive a child and carry to term is significantly decreased. By the time she is 40 the chances of her conceiving is about five percent each ovulation cycle. By the time she reaches her mid-forties, the ability to bear children is, for most women, lost. The reason for this being that both the quantity and quality of eggs decreases. The team at Yale, set out to understand why the quality of eggs was degraded as women aged. Their findings were very interesting.

The Study

Researchers knew that after the age of 40 the cumulus cells that nurture eggs begin to die. This causes the quality of the egg to be affected, decreasing chances of conception as well the odds of carrying a pregnancy to term. To understand what causes these cells to die, the team studied cumulus cells from patients under the age of 35 and cumulus cells of patients over 40. They found extreme differences in the RNA structure between the two groups. Lack of oxygen to these cells was found to be the main cause of dying off and disturbances in the RNA. Pasquale Patrizio, M.D., director of Yale Fertility Center and professor in the Department of Obstetrics, Gynecology and Reproductive sciences said, “Our data show that cumulus cells from older women are affected by chronic exposure to suboptimal oxygen levels, as indicated by an increased expression of hypoxia-induced genes when compared to the same cells collected in younger patients.”

What This Means

The findings of this study are remarkable. With this knowledge fertility doctors may soon be able to help women participating in IVF treatments choose eggs that are the most viable based on how much oxygen is present in the cumulus cells that surround them. Understanding what causes eggs to respond to the “biological clock” may lead to modifying ovarian stimulation protocols and can hopefully lead to more successful in vitro fertilization treatments all together.

Age and Fertility

Women are born with as many eggs as they will ever have; this is referred to as the, “ovarian reserve.” While every woman is different, by the age of 35 a sharp decline in fertility is exhibited and experiencing loss of ovarian reserve is normal. As the amount of eggs declines, the remaining eggs become less sensitive to follicle-stimulating hormones making it even more difficult to conceive. Concurrently, the decreased amount of oxygen in the cumulus cells surrounding oocytes causes degradation in quality of eggs. The diminished quality of eggs is normally exhibited as too many or not enough chromosomes, also known as aneuploidy. The combination of decreased sensitivity to FSH, diminished ovarian reserve, and decline in egg quality makes it extremely difficult for women over the age of 40 to bear a child. Sadly at this point in time there is nothing a woman is able to do to increase these oxygen levels or to protect her ovarian reserve.

There is no reason to give up your hope of a family however. With more and more women choosing to delay childbearing, and the many studies being conducted to understand better the role maternal and paternal age plays in fertility, there will always be hope of new technology allowing families to flourish.  If you are worrying about your ability to begin a family as you get older or are wanting to put off having children until you are ready, contact us at Viera Fertility Center today. We will be able to discuss with you your options and possible treatments available to help you bring the family of your dreams into the world.