Standard early pregnancy screening for Down syndrome is known as combined screening, and doctors use three sets of numbers to estimate a fetus’s risk of developing this genetic defect: the characteristic values of the mother’s blood, the thickness of the fetus’s nuchal translucency (NT, the tissue in the region of the back of the neck) measured by ultrasound, and the mother’s age. The risk factor that parents and parents-to-be are probably most familiar with is this last one – it is well known that the older the mother, the higher the risk of genetic abnormalities in the baby. Down syndrome occurs in fetuses when there is an extra chromosome 21 in the egg. The risk of such errors rises as a woman ages. However, what this algorithm doesn’t take into account is the fact that the sperm’s chromosome 21 may also be adhering excess genetic material. Scientists generally believe that about 5 to 10 percent of Down syndrome cases can be attributed to the patient’s father, and some even believe that the percentage could be as high as 20 percent. As a man ages, his child’s risk of Down syndrome may also rise – the older the father, the higher the probability that the process of making sperm will go wrong, which could lead to problems with the sperm, such as an extra chromosome.In 2003, several scientists surveyed New York State’s health records, and as a result, they found that Down syndrome could be as high as 50 percent among parents over age 40 because of the father. “Genetic anomalies are not just a female problem,” said Harry Harry Fisch, a professor of urology at Weill Cornell Medical College and the study’s first author, said, “Couples are having children later in life now than they used to, and so the problem becomes particularly acute.” However, the combined screening only took into account the mother’s age, partly because we still don’t study the father’s age well enough to accurately include it in the calculation of risk factors. It was long thought that paternal age was only associated with some relatively rare genetic abnormalities, such as Klinefelter syndrome, chondrodysplasia, and dwarfism-until about the last 15 years, when a number of studies have suggested that paternal age may be associated with some more common disorders, such as autism and schizophrenia, a factor that has gradually received more attention from the research community. “The question is, why aren’t enough people paying attention to this? There is still far more interest in maternal than paternal factors. It will take a long time to change that.” Fisch said. The risk of giving birth to a child with Down syndrome has clear values for mothers of different ages, and these values do not take into account the influence of the father. Image source: http://www.ndss.org/ The Neglected “Father of the Year” Geneticist Helga Torrello, who is the author of the book “The Father of the Year”, says that the risk of having a child with Down’s Syndrome is very high. Geneticists Helga Toriello and Jeanne Meck have shown that the risk of “advanced paternal age” has been neglected. Geneticists Helga Toriello and Jeanne Meck, who co-wrote a genetic counseling guide for older new fathers, say that pregnancies of 35 and older are classified as “advanced maternal age,” but at the same time, the medical community has yet to define “advanced paternal age. “The medical community has yet to define “advanced age fatherhood. “There are studies for men over 40, and there are studies for men over 50 or 35.” Torrello said. While the findings suggest that fathers over the age of 40 have the most significant impact on their children; fathers who are too young may also be at greater risk, perhaps because the process of sperm formation in that population is more likely to result in mutations similar to those found in older people. A recent study showed that fathers in their 20s were twice as likely to have a child with Down syndrome as fathers in their 40s. However, we don’t currently know enough about the impact of the father’s age, so it’s hard to tell exactly how accurate the existing combined Down syndrome screening is. 49-year-old mothers have a 1 in 9 chance of having a child with Down syndrome – but the existing screening doesn’t take into account whether the child’s father is 24 or 64 years old. Under the current algorithm, a different risk factor corresponding to each year of the mother’s age would have to be used in the calculations; given that women usually have children with men older than themselves, it’s still not clear to us whether the father’s age has already crept in to affect the value of this risk factor. “We would need to take data from a sample of 49-year-old women having children with men in their 20s, then with men in their 30s, and so on, to be able to observe the difference.” Torrello said. Fisch’s study comes closest to this model, but no one else has replicated the study on a larger scale yet. “The most important problem is that we haven’t found a suitable direction to assess the impact of the father’s age on (existing) maternal risk factors,” Torrello said. Also, the medical professionals responsible for administering screenings and interpreting test results to patients may not understand the impact of the father’s age. “I think there’s a lot we don’t know in this field,” says Meck, “and a lot of OB/GYNs don’t know enough about prenatal screening. Internists are strapped for time and don’t have a comprehensive enough knowledge base, and those clinics with genetic counselors fare best on these kinds of issues.” The Risk Comes From Both Parents In recent years, some doctors have begun to abandon combined screening and other invasive screening techniques in favor of a newer, noninvasive prenatal test that uses placental cells floating in the mother’s bloodstream to check fetuses for chromosomal abnormalities. As this approach spreads, age-based assessment systems may be phased out. Noninvasive prenatal testing is more accurate than combined screening – the former can detect up to 93 percent of cases compared to 82 to 87 percent – and can be performed as early as the 10th week of pregnancy. Best of all, noninvasive prenatal testing does not rely on any algorithms to assess risk, so there’s no need to worry about age, either of the father or the mother. (In the United States, noninvasive prenatal testing may be included as an optional alternative to combined screening, but Medicare may not be able to cover the expense.) Nonetheless, once sperm and eggs are involved, there are still some outdated stereotypes in standard clinical practice, such as the insistence on using combined screening to assess Down syndrome risk. This screening takes into account only the age of the mother, and therefore gives the false impression that genetic abnormalities are only related to the age of the mother – a woman’s eggs “spoil” over time, just as food on the supermarket shelves does, while a man’s eggs can “spoil” regardless of age, just as food on the supermarket shelves does. Men can produce fresh, vital sperm, no matter how old they are. The age of the father is rarely a factor when it comes to having children. Image credit: shutterstock Current research results have proven the absurdity of this old notion. Older men do still make sperm, but the number of sperm decreases , and the probability of mutation increases. “There are a lot of things that can go wrong in the process of making sperm,” says Patricia Hunt, a reproductive biologist at Washington State University. Patricia Hunt, a reproductive biologist at Washington State University, said, “like a machine gradually aging and rusting.” Meanwhile, scientists are just beginning to realize the impact of the father’s age on sperm. “I think what we’re seeing right now is just the tip of the iceberg,” says Fahey, “and we don’t really know what other effects the father’s age has.” (Edit: odette) An AI Blame women for not being able to have children, blame women for children being female, blame women for unhealthy children, and blame women for low fertility rates. …… Are the scientific developments over the years aimed at the “dumpers” in a directed slap in the face? –No, science only cares about the truth and how to combat it. Do you think everyone is like you and only thinks about how to pass the buck?