Women found to have only 12 percent of ‘ovarian reserve’ by age 30

January 27, 2010 by Shawn Douglas
Filed under: News, Pregnancy

New research suggests that by the age of 30, a woman’s ovarian reserve may dwindle to only 12 percent of what they were born with.

Are you a woman waiting to conceive a child until after the age of 30? New research provides further evidence of the challenges that await you if you do.

Researchers out of the University of St. Andrews and Edinburgh University have collected data on 325 women from the U.K., U.S. and parts of Europe. The women represented a broad range of ages and had their reserve of eggs assessed.

The data was then plotted on a graph to provide a clearer picture of potential decline in the ovarian reserve of women from conception to menopause.

They found that on average, roughly 300,000 egg cells exist as a newborn, but the researchers were surprised at how quickly the available reserve declined in women.

Co-author of the study, Dr. Hamish Wallace, said of the decline: “Our research shows that they are generally over-estimating their fertility prospects. Our model shows that for 95 percent of women, by the age of 30 years, only 12 percent of their maximum ovarian reserve is present, and by the age of 40 years only three percent remains.”

The researchers also found significant variance in the size of women’s ovarian reserves. Some women were found to have nearly two million egg cells while others had counts as low as 35,000.

The research, published in the journal Public Library of Science One, supports other research findings that women who wait until their 30s or later are at significant risk of fertility-related problems.

Dr. Tom Kelsey, a study researcher at St. Andrews, said: ‘Women often do not realize how seriously ovarian reserve declines after the age of 35. Every year that goes by you are losing a big proportion of your ovarian reserve.”

Some doctors already suggest that women should receive fertility screening at the same time they receive screenings for cervical cancer. A simple blood test that measures the amount of estradiol, the predominate sex hormone in females, can be performed by a gynecologist. The test can measure the potential reserve of eggs a woman has, determining if she has a reasonable chance for conception.