Due to hormone fluctuations, older women tend to release more than one egg at a time, explaining why they tend to have twins. The studies conducted at Amsterdam's Vrije University explain why non-identical twins, those born from two eggs fertilized in the same time, are born in a time when fertility is declining. Dr. Roy Homburg, the study's co-author, stated: "We have shown that older women have an increased tendency to multiple, simultaneous ovulations, and as FSH [follicle-stimulating hormone] levels are constantly rising in this age group; we believe that an overshoot of the FSH rise causes an increased frequency of multiple ovulations." The scientist analyzed 959 cycles of egg development of about 500 women artificial inseminated. "Ovarian function declines as women get older, affecting fertility and eventually resulting in infertility. But in between fertility and infertility is this gray zone, where things happen that are out of character," stated Dr. Jaime Grifo, director of reproductive endocrinology at New York University Medical Center. This gray area Grifo talks about is characterized by a high chance of fraternal twins. In today's world, women are used to delay the pregnancy. From 35 years on, ovaries embark on the road to menopause, having a decreasing number of eggs, some of which incapable of being fertilized. These facts, as terrible as they sound, are not known by many women, thus risking their chances for a descendant. Even if twins might seem a good piece of news, as one of the researchers said, "isn't all it's made out to be".