Another study , examining data from , pregnancies in the United Kingdom, observed that the rate of stillbirth was 4. Researchers from the Albert Einstein College of Medicine of Yeshiva University in New York learned that the genetic process of recombination could be responsible for the increased risk of conditions such as Down syndrome. Risks of delaying pregnancy until age 35 years or older Fertility declines in both men and women with age. By Hannah Nichols The trend toward older parenthood looks set to continue, with more women in their 30s having babies now than women in their 20s. However, this decreased to 61 percent of individuals between the ages of 31 to 34, and it further declined to 54 percent of women aged 35 and over. While these risks become slightly more likely after hitting 35 years old, this does not mean that they will have a significant impact on everyone in their mid-thirties and older. Everyone is aware of the ticking of the biological clock, but does your 35th birthday represent a particularly special milestone in biology? Do you hit 35 and suddenly become "high risk" overnight? Women are delivering healthy babies throughout their 30s and beyond. Other risks Research comparing pregnancy complications among women aged 18 to 34 years, 35 to 40 years, and 40 and over, found small increases in most pregnancy- and birth-related complications with age. Expectant parents are typically well aware of the risks associated with late pregnancy, but they are less aware of the positive effects. Research presented at the American Stroke Association's International Stroke Conference revealed that compared with women who go through pregnancy at a younger age, pregnant women aged 40 and older are at greater risk of ischemic stroke , hemorrhagic stroke, heart attack , and death from cardiovascular disease.