In 2006, the Spanish native of Cadiz, María Del Carmen Posada de Lara, became famous. The 66-year-old woman became the oldest woman in the world’s medical history when she gave birth to twins through fertility. In 2008, Indian woman Devi Logan became a mother for the first time at the age of 70 through in vitro fertilization. According to the March issue of the Spanish monthly magazine Fun, this assisted reproduction is common for women in their 50s in India, a country where the culture of not having an heir is considered a stigma. These two examples are extreme instances of a phenomenon that is common worldwide. Globally, more and more women are defying the laws of nature with the help of medical treatments and completing childbirth as advanced maternal age, even some who have already reached menopause. The statistics bear out this trend. In the United States, official statistics show that the number of women over the age of 35 who become pregnant and have children has doubled since the 1980s, and the number of women over 40 who have children has quadrupled. On the European continent, Spain is the second most delayed birth for women in the European Union, after Italy. Spain’s National Statistics Institute noted that 33 percent of Spanish women who gave birth in 2014 were over the age of 35. Although births at higher ages are uncommon, the number of women over 40 visiting obstetrics has increased by 4 percent since 2000. Over the past few decades, various family planning programs have been working to avoid unplanned pregnancies. The ability to make decisions on such an important matter of human life has affected sexual and conjugal relationships, as well as the environment in which they take place. In the West, few people today talk about having more than two siblings, and large families with many members have largely disappeared today. People are having fewer and fewer children, and are having them later and facing difficulties along the way. The dilemmas to be faced are obvious. Biologically speaking, the optimal age for having children also happens to be when people devote most of their energy to their careers or to enjoying their lives. Choices made at this time may have implications for the future. No one can explain, in strictly scientific terms, how fertility goes downhill. All that is known is that it does, but there are many factors that influence it: age, health status, personality, frequency of sex, etc. When it comes to female fertility, the most frequently cited survey is that 1 in 3 women between the ages of 35 and 39 are unable to conceive despite trying for more than a year. Henri Leridon of the French National Institute for Demographic Research has been trying to prove whether assisted reproductive technology can curb the decline in fertility rates caused by delayed childbearing. In a survey he published in 2004, Leridon firmly stated, “Even if we take some aspects of this research lightly, it is indisputable that assisted reproductive technology still cannot compensate for the loss of fertility caused by age. However, there is a weakness in the French scientist’s research, which is based on data from 1670 to 1830. It is true that during this period women began to have fewer and fewer children from the age of 30, but it is also important to take into account that there were no antibiotics and no advanced medical care. In an environment so different from today’s, perhaps the most common form of contraception was to have less sex, thereby reducing fertility, but that does not mean that people were less fertile. The data published by maternity hospitals are more convincing in the discussion of declining fertility and its causes. The Spanish Society for Assisted Reproductive Technology states that the younger a woman is, the more likely she is to conceive after artificial insemination. However, this is a relative situation, since it is also necessary to consider couples who undergo this treatment for their own fertility problems, and whose fertility is not a universal phenomenon. In addition, according to the Spanish Society for the Study of Reproductive Biology, only about 16,000 babies are born each year in Spain with the help of assisted reproduction, which represents only 4 percent of the annual births. Mary Herbert, a professor of reproductive biology at Newcastle University in the United Kingdom, believes that there is no need to delay births. Herbert argues that there is no need to delay childbirth. Her 20-year study of the effects of reproductive aging concluded that the decline in egg numbers over time is an irreversible process. “Women are destined at birth to have nearly 2 million eggs during their lifetime, and this number decreases month by month until they reach menopause. And the changes caused by age affect not only the number of eggs, but also their quality.” Herbert said. According to Herbert, it is a mistake to expect assisted reproductive technology to extend the ideal fertility period. She also believes that egg freezing, which is now in full swing, does not guarantee healthy fertility, not to mention the high cost. She points out that delaying childbearing increases the risk of chromosomal triploidy. This is a chromosomal ploidy caused by a genetic disorder in which a pair of chromosomes gets three instead of the normal two when the body’s cells divide. Statistics show that more than 65% of newborns born with Down syndrome in the UK in 2008 had parents over the age of 35. The problem is not limited to the United Kingdom, as U.S. medical authorities state that babies born with this genetic disorder are five times more likely to occur in older mothers than in others. The reduction in integrins leads to premature division of sister chromatids, which can lead to abnormal chromosome arrangements and misdivision. Herbert notes, “From a certain age, the concentration of integrins in experimental mice decreases to the point where it is not enough to stabilize the chromosomal halves. They develop genetic disorders, such as aneuploidy and triploidy.” In addition, “integrins play a crucial role in the relationship between chromosome segregation and female aging. During the first decade or so of fertility, young eggs are healthy. But as they age, integrins begin to decrease, thus causing erratic ovulation”. Herbert’s point is clear: it’s better to have children before it’s too late. Kenneth Rothman, a scientist at Boston University, has a different view on this issue. Rothman studied the natural decline in fertility in 2,820 women of all ages who did not have fertility problems. He noted, “Fertility does decline with age, but time is not the main factor. We should also take into account various other factors, such as whether the woman is already a mother.” The data he collected showed that in the 20- to 34-year-old age group, they were 84 percent more likely to become pregnant, and in the 35- to 40-year-old age group, the likelihood decreased to 78 percent. Psychological factors also contribute to delayed pregnancy. A University of California survey revealed that some women who had children after age 40 with assisted reproductive technology noted that they made the right decision. These couples felt more prepared for the issue of having a child, were less nervous and enjoyed the process. Elizabeth Gregory, director of the Women’s Studies Program at the University of Houston, agrees that older mothers are actually more emotionally stable, more prepared for pregnancy and childbirth and for educating their children, and often already have some financial resources. A survey by University of Southern California fertility expert Richard Paulson points out that older mothers face less pressure to be parents, they are psychologically intact and they don’t feel more strenuous than younger mothers. The report says that having a child at an advanced age may also extend the mother’s life expectancy. Boston University School of Medicine spent 20 years studying the health of centenarians to determine what factors make them live longer, or why they age with such high quality. The study found that women who had children after age 40 were four times more likely to live past 100. “According to Thomas Perls, who heads the New England Centenarian Study, “women who have children after age 40 are four times more likely to live beyond 100. According to Perls, “The fact that their reproductive systems are in perfect condition is evidence that other organs in their bodies are also functioning well. We don’t rule out the possibility that living with children can help extend life span. In vitro fertilization also does not appear to cause damage to the babies born. In 2008, scientists at the University of Iowa compared the academic performance of 423 young people to see if reproductive technology, which was well established more than 30 years ago, could have a negative impact on cognitive development. The study concluded that the IVF babies’ academic performance was equal to or better than that of other students. Parents would be more concerned about their children’s education if their mothers were of advanced maternal age. Another issue related to advanced maternal age is whether leaving the child in the care of strangers will have an impact on the child. Few couples can accept a model in which one partner does not work, and the grandparents who usually take care of newborns in Spain may be too old to provide substantial help. For the child, it is a complex adjustment process. Parents are aware that this is a difficult time, but at the same time may find it beneficial to develop their child’s social skills. However, some recent studies have questioned this. In the late 1990s, the Canadian province of Quebec subsidized kindergartens that accepted children under the age of five to help mothers return to work. The measure was extremely well received. Jonathan Gruber, an economist at the Massachusetts Institute of Technology, notes, “It gave us a large database that we could use for research on the impact of kindergarten on young children.” Gruber and his Canadian colleagues have been tracking and analyzing this government policy for 10 years since then. They analyzed the behavior, perceptions and health of children who spent most of their time in kindergarten and concluded that this was not a good approach, especially for young children. Gruber noted that “young children who are educated in kindergarten from an early age are more hyperactive, less focused, more aggressive, more prone to illness, and have deteriorating relationships with their parents. Researchers from Columbia University and Duke University studied mother-child relationships in 2,000 families. They found that children who had been separated from their mothers for at least a week before age 2 were more likely to be passive and aggressive by ages 3 to 5. “The parent-child relationship takes time to develop. If that relationship is interrupted, it can have social-emotional and perhaps cognitive consequences.” said Kimberly Howard, one of the study’s project leaders. When it comes to fertility, almost all analyses focus on women. Few studies point out that men’s fertility actually wanes over time as well. Some recent studies have suggested that a father’s age may be associated with some of the child’s disorders, such as autism, Abel’s disease and dwarfism. But much research is needed to understand what factors contribute to such effects. The specific processes that regulate and constrain reproductive capacity and the consequences of delaying childbearing are not yet known. Biologically speaking, reproduction is our destiny as a species. Is this destiny now at risk?