The wikipedia entry on Advanced Maternal Age reads like an intentionally persuasive call to action for women to have children before age 30.
read the full poopstain here
Advanced maternal age is associated with adverse reproductive effects such as increased risk of infertility,[4] and that the children will have chromosomal abnormalities.[5] The corresponding paternal age effect is less pronounced.[6][7]
It is readily accepted that advanced paternal age 'doesn't really matter', judging by the non-chalant mentions it gets across the web and minimal consideration it gets from doctors of conceiving couples. It hasn't been studied as rigorously. Consider that women were once thought responsible for the gender of the child and, in most cvilizations, blamed for the inability to conceive. Sometimes women were even killed or disavowed for not producing males. It's a historical tradition and human instinct to assume maternal factors first, from status quo before evidence.
Older fathers may contribute just as much as older mothers to the dramatic increase in Down syndrome risk faced by babies born to older couples. A new study found that older fathers were responsible for up to 50% of the rise in Down syndrome risk when the mother was also over 40.
http://www.webmd.com/infertility-and-reproduction/news/20030701/dad-age-down-syndrome
The subtext of the promoting the maternal age concern is a belief it's preferable women have children younger for the good of society. The subtext of that is a belief women should make sacrifices; sacrifice reaching personal goals and learning whether they're cut out for motherhood via life experience (there is a cultural archetype, subconscious expectations, that women should be self-sacrificing, but that's a whole other story).
My experience is that I very much wanted my biological children 'someday' when I was 18-21, then when I learned more about life and myself I changed my mind with complete confidence. Bullet dodged. I know a few women who had kids in their 20's, who said going back in time they wouldn't choose to have children again (despite loving the ones they have.) Not an easy thing to admit.
Maria Guido writes of her bizarre experience with maternal age stigma:
I’m 39, so I was approached as if I was some sort of dinosaur with dried up eggs attempting to have a child. After I was informed of the hundreds of genetic defects that a child that emerged from my old womb could have, I was offered a series of genetic tests to go along with the routine first trimester NT scan. [...]
A receptionist from my birthing center called me after she received those results to inform me that they had found some “soft markers” for genetic defects, and I should consider getting an amniocentesis.[...]
Her[Clinic Receptionist]: The screen shows that your baby has an elevated risk for Down’s Syndrome. Your probability came out 1 in 255.
One in 255? I’m not really a math person, but those seem like some pretty good odds to me.
Me: Is there any way we can start with the results from the test I took that has a 99% detection rate, instead of the one that has an 80% detection rate?
Her: Oh. Let me look. (flips through chart for two minutes) Here it is. This one is saying you are low risk for all of the genetic abnormalities it tests for. But because of your age and poor OB history, I think you should still have an amnio.
Me: Really? Why did I even bother to take the other test if it is coming back negative and you are still recommending an amnio?
Her: I’m not a geneticist. I can’t interpret the results. But you know, you’re not 20 – you’re 39.
From: "I Said I Refused To Be Freaked Out By My ‘Advanced Maternal Age.’ I Lied" by Maria Guido link
Today I learned genetic tests are pushed on pregnant women dependent on age range!
The advanced reproductive age effect is just another societal grey-goo boogey baby; fear-based and easily spread by mimicry and uninformed repetition based on peoples biases which lead them to readily believe things true which suits their personal beliefs. That shit deserves a run-on sentence.
So the premise is the increased risks of birth defects is undesireable, maybe even taboo to have a child if high risk is known. The concern is not just for downs-syndrome, but an overall higher risk of predisposed genetic defects for the individual. The slippery slope is that line of thinking can justify 'eugenics' as well.
Perhaps a better solution can arise someday where affordabe genetic testing is available to all at low or zero cost. This could also mean women and men of optimal fertility age may want to try such testing too, were they not prohibted from access due to being 'low risk' group (as things usually go when alotting healthcare resources.)
The prejudice would only extend; someone enacting their right to choose to go through with pregnancy despite a high genetic risk would inevitably fall under the same criticism as older mothers now.
That is the why discrimination against advanced maternal age is about social control and not science.
It justifies the status quo of older male younger female couplings. Which is more of an urban legend than commonality anyway. Statistics show ~60% of couples are within 1 to 3 years of eachother and a small minority over five years (data from USA, UK, Australia taken from Wikipedia (I won't bother looking further than wikipedia on this one.)
The fear-factor has people over-concened about maternal age. where a headline reads: "Study Confirms Link between Older Maternal Age and Autism" the end quote by the study's scientist is "Although it is rising, the risk of autism is still very low and shouldn't affect the decision to have children at any age,"
There is more social-cultural bias and stigma against older female and younger male couples than vice-versa. People question it, make assumptions about each partners intentions, etc.
Speculations:
The status quo of acceptable age differences in hetero couples may change. If women can avoid the advanced maternal age risk by bearing children of men much younger than themselves, women who wish to have children later in life may consider that in mate choice. Women have a lot more say in matters of reproduction and mate choice at any age, if you look at the reality and not the colloquialisms of fertility-based female mate selection (maybe some wishful thinking that with age male choice holds more power than female choice.) Combine that with women becoming equal or higher earning as men, it could very well be a custom one day to see more or just as many 45 year old women with 35 year-old men than vice-versa. Such seemingly significant social shifts are threatening, we have an instinct to resist change to 'tradional values' and the way things are always done. And so socially spread mythos about autistic bogey-babies with down-syndrome are born.
A study released in 2003 by the United Kingdom's Office for National Statistics concluded that the proportion of women in England and Wales marrying younger men rose from 15% to 26% between 1963 and 1998.
A 2003 AARP study reported that 34% of women over 39 years old were dating younger men
Regardless, statistics show that most couples are within the same age by 3 years and that is is a natural choice to want a life mate around the same age; relatable. Divorce statistics often say large age differences are a divorce factor.
My take 'n stake in all this:
It is self-righteous and useless to care about other people's preferences of parental age, spouses, singledom, polyamoury, abortion, sperm-donor vs. husband, or remaining childfree (you can't be childless if you never had a child.)
Ultimately, statistics shouldn't dictate personal choice in this matter. Whether social taboo or enforced via policy and custom, it is social control.